[PATCH v5 12/14] i2c: octeon: Split the driver into two parts
From: Jan Glauber
Date: Thu Mar 31 2016 - 06:29:09 EST
Move common functionality into a separate file in preparation of the
re-use from the ThunderX i2c driver.
Signed-off-by: Jan Glauber <jglauber@xxxxxxxxxx>
---
drivers/i2c/busses/Makefile | 3 +-
drivers/i2c/busses/i2c-cavium.c | 822 +++++++++++++++++++++++++++++
drivers/i2c/busses/i2c-cavium.h | 195 +++++++
drivers/i2c/busses/i2c-octeon-core.c | 983 +----------------------------------
4 files changed, 1020 insertions(+), 983 deletions(-)
create mode 100644 drivers/i2c/busses/i2c-cavium.c
create mode 100644 drivers/i2c/busses/i2c-cavium.h
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 3405286..282f781 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -91,7 +91,8 @@ obj-$(CONFIG_I2C_UNIPHIER) += i2c-uniphier.o
obj-$(CONFIG_I2C_UNIPHIER_F) += i2c-uniphier-f.o
obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o
obj-$(CONFIG_I2C_WMT) += i2c-wmt.o
-obj-$(CONFIG_I2C_OCTEON) += i2c-octeon-core.o
+i2c-octeon-objs := i2c-cavium.o i2c-octeon-core.o
+obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o
obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o
obj-$(CONFIG_I2C_XLR) += i2c-xlr.o
obj-$(CONFIG_I2C_XLP9XX) += i2c-xlp9xx.o
diff --git a/drivers/i2c/busses/i2c-cavium.c b/drivers/i2c/busses/i2c-cavium.c
new file mode 100644
index 0000000..9ad1f23
--- /dev/null
+++ b/drivers/i2c/busses/i2c-cavium.c
@@ -0,0 +1,822 @@
+/*
+ * (C) Copyright 2009-2010
+ * Nokia Siemens Networks, michael.lawnick.ext@xxxxxxx
+ *
+ * Portions Copyright (C) 2010 - 2016 Cavium, Inc.
+ *
+ * This file contains the shared part of the driver for the i2c adapter in
+ * Cavium Networks' OCTEON processors and ThunderX SOCs.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include "i2c-cavium.h"
+
+static int reset_how;
+
+/* interrupt service routine */
+irqreturn_t octeon_i2c_isr(int irq, void *dev_id)
+{
+ struct octeon_i2c *i2c = dev_id;
+
+ i2c->int_dis(i2c);
+ wake_up(&i2c->queue);
+
+ return IRQ_HANDLED;
+}
+
+static void octeon_i2c_disable_hlc(struct octeon_i2c *i2c)
+{
+ if (!i2c->hlc_enabled)
+ return;
+
+ i2c->hlc_enabled = false;
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
+}
+
+#define I2C_OCTEON_IFLG_WAIT 80 /* microseconds */
+
+/*
+ * Wait-helper which addresses the delayed-IFLAG problem by re-polling for
+ * missing TWSI_CTL[IFLG] a few us later, when irq has signalled an event,
+ * but none found. Skip this re-poll on the first (non-wakeup) call.
+ */
+static int poll_iflg(struct octeon_i2c *i2c, int *first_p)
+{
+ int iflg = octeon_i2c_test_iflg(i2c);
+
+ if (iflg)
+ return 1;
+ if (*first_p)
+ *first_p = 0;
+ else {
+ usleep_range(I2C_OCTEON_IFLG_WAIT, 2 * I2C_OCTEON_IFLG_WAIT);
+ iflg = octeon_i2c_test_iflg(i2c);
+ }
+ return iflg;
+}
+
+/**
+ * octeon_i2c_wait - wait for the IFLG to be set
+ * @i2c: The struct octeon_i2c
+ *
+ * Returns 0 on success, otherwise a negative errno.
+ */
+static int octeon_i2c_wait(struct octeon_i2c *i2c)
+{
+ long time_left;
+ int first = 1;
+
+ if (i2c->broken_irq_mode) {
+ /*
+ * Some chip revisions seem to not assert the irq in
+ * the interrupt controller. So we must poll for the
+ * IFLG change.
+ */
+ u64 end = get_jiffies_64() + i2c->adap.timeout;
+
+ while (!octeon_i2c_test_iflg(i2c) &&
+ time_before64(get_jiffies_64(), end))
+ udelay(50);
+
+ return octeon_i2c_test_iflg(i2c) ? 0 : -ETIMEDOUT;
+ }
+
+ i2c->int_en(i2c);
+ time_left = wait_event_timeout(i2c->queue, poll_iflg(i2c, &first),
+ i2c->adap.timeout);
+ i2c->int_dis(i2c);
+
+ if (time_left <= 0 && i2c->broken_irq_check &&
+ octeon_i2c_test_iflg(i2c)) {
+ dev_err(i2c->dev,
+ "broken irq connection detected, switching to polling mode.\n");
+ i2c->broken_irq_mode = true;
+ return 0;
+ }
+ if (!time_left) {
+ dev_dbg(i2c->dev, "%s: timeout\n", __func__);
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+
+/*
+ * Cleanup low-level state & enable high-level.
+ * Returns -EAGAIN if low-level state could not be cleaned.
+ */
+static int octeon_i2c_enable_hlc(struct octeon_i2c *i2c)
+{
+ int try = 0, ret = 0;
+ u64 val;
+
+ if (i2c->hlc_enabled)
+ return 0;
+ i2c->hlc_enabled = true;
+
+ while (1) {
+ val = octeon_i2c_read_ctl(i2c) & (TWSI_CTL_STA | TWSI_CTL_STP);
+ if (!val)
+ break;
+
+ /* clear IFLG event */
+ if (val & TWSI_CTL_IFLG)
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
+
+ if (try++ > 100) {
+ pr_err("%s: giving up\n", __func__);
+ ret = -EAGAIN;
+ break;
+ }
+
+ /* spin until any start/stop has finished */
+ udelay(10);
+ }
+
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
+ TWSI_CTL_CE | TWSI_CTL_AAK | TWSI_CTL_ENAB);
+ return ret;
+}
+
+static int octeon_i2c_lost_arb(u8 code, int final_read)
+{
+ switch (code) {
+ /* Arbitration lost */
+ case STAT_LOST_ARB_38:
+ case STAT_LOST_ARB_68:
+ case STAT_LOST_ARB_78:
+ case STAT_LOST_ARB_B0:
+ return -EAGAIN;
+
+ /* Being addressed as slave, should back off & listen */
+ case STAT_SLAVE_60:
+ case STAT_SLAVE_70:
+ case STAT_GENDATA_ACK:
+ case STAT_GENDATA_NAK:
+ return -EIO;
+
+ /* Core busy as slave */
+ case STAT_SLAVE_80:
+ case STAT_SLAVE_88:
+ case STAT_SLAVE_A0:
+ case STAT_SLAVE_A8:
+ case STAT_SLAVE_LOST:
+ case STAT_SLAVE_NAK:
+ case STAT_SLAVE_ACK:
+ return -EIO;
+
+ /* ACK allowed on pre-terminal bytes only */
+ case STAT_RXDATA_ACK:
+ if (!final_read)
+ return 0;
+ return -EAGAIN;
+
+ /* NAK allowed on terminal byte only */
+ case STAT_RXDATA_NAK:
+ if (final_read)
+ return 0;
+ return -EAGAIN;
+ case STAT_TXDATA_NAK:
+ case STAT_TXADDR_NAK:
+ case STAT_RXADDR_NAK:
+ case STAT_AD2W_NAK:
+ return -EAGAIN;
+ }
+ return 0;
+}
+
+static int check_arb(struct octeon_i2c *i2c, int final_read)
+{
+ return octeon_i2c_lost_arb(octeon_i2c_read_sw(i2c,
+ SW_TWSI_EOP_TWSI_STAT), final_read);
+}
+
+/* send STOP to the bus */
+static void octeon_i2c_stop(struct octeon_i2c *i2c)
+{
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
+ TWSI_CTL_ENAB | TWSI_CTL_STP);
+}
+
+/**
+ * octeon_i2c_unblock - unblock the bus
+ * @i2c: The struct octeon_i2c
+ *
+ * If there was a reset while a device was driving 0 to bus, bus is blocked.
+ * We toggle it free manually by some clock cycles and send a stop.
+ */
+static void octeon_i2c_unblock(struct octeon_i2c *i2c)
+{
+ int state, i;
+
+ octeon_i2c_disable_hlc(i2c);
+ dev_dbg(i2c->dev, "%s\n", __func__);
+
+ /* cycle 8+1 clocks with SDA high */
+ for (i = 0; i < 9; i++) {
+ octeon_i2c_write_int(i2c, 0);
+ udelay(5);
+ state = __raw_readq(i2c->twsi_base + TWSI_INT);
+ if (state & (TWSI_INT_SDA | TWSI_INT_SCL))
+ break;
+ octeon_i2c_write_int(i2c, TWSI_INT_SCL_OVR);
+ udelay(5);
+ }
+ /* hand-crank a STOP */
+ octeon_i2c_write_int(i2c, TWSI_INT_SDA_OVR | TWSI_INT_SCL_OVR);
+ udelay(5);
+ octeon_i2c_write_int(i2c, TWSI_INT_SDA_OVR);
+ udelay(5);
+ octeon_i2c_write_int(i2c, 0);
+}
+
+/*
+ * TWSI state seems stuck. Not sure if it's TWSI-engine state or something
+ * else on bus. The initial _stop() is always harmless, it just resets state
+ * machine, does not _transmit_ STOP unless engine was active.
+ */
+static int start_unstick(struct octeon_i2c *i2c)
+{
+ octeon_i2c_stop(i2c);
+
+ /*
+ * Response is escalated over successive calls,
+ * as EAGAIN provokes retries from i2c/core.
+ */
+ switch (reset_how++ % 4) {
+ case 0:
+ /* just the stop above */
+ break;
+ case 1:
+ /*
+ * Controller refused to send start flag. May be a
+ * client is holding SDA low? Let's try to free it.
+ */
+ octeon_i2c_unblock(i2c);
+ break;
+ case 2:
+ /* re-init our TWSI hardware */
+ octeon_i2c_init_lowlevel(i2c);
+ break;
+ default:
+ /* retry in caller */
+ reset_how = 0;
+ return -EAGAIN;
+ }
+ return 0;
+}
+
+/**
+ * octeon_i2c_start - send START to the bus
+ * @i2c: The struct octeon_i2c
+ * @first: first msg in combined operation?
+ *
+ * Returns 0 on success, otherwise a negative errno.
+ */
+static int octeon_i2c_start(struct octeon_i2c *i2c, int first)
+{
+ int result;
+ u8 data;
+
+ octeon_i2c_disable_hlc(i2c);
+
+ while (1) {
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
+ TWSI_CTL_ENAB | TWSI_CTL_STA);
+
+ result = octeon_i2c_wait(i2c);
+ data = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
+
+ switch (data) {
+ case STAT_START:
+ case STAT_RSTART:
+ if (!first)
+ return -EAGAIN;
+ reset_how = 0;
+ return 0;
+ case STAT_RXADDR_ACK:
+ if (first)
+ return -EAGAIN;
+ return start_unstick(i2c);
+ /*
+ * case STAT_IDLE:
+ * case STAT_ERROR:
+ */
+ default:
+ if (!first)
+ return -EAGAIN;
+ start_unstick(i2c);
+ }
+ }
+ return 0;
+}
+
+static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c)
+{
+ u64 val = __raw_readq(i2c->twsi_base + SW_TWSI);
+
+ return (val & SW_TWSI_V) == 0;
+}
+
+static void octeon_i2c_hlc_int_clear(struct octeon_i2c *i2c)
+{
+ /* clear ST/TS events, listen for neither */
+ octeon_i2c_write_int(i2c, TWSI_INT_ST_INT | TWSI_INT_TS_INT);
+}
+
+/**
+ * octeon_i2c_hlc_wait - wait for an HLC operation to complete
+ * @i2c: The struct octeon_i2c
+ *
+ * Returns 0 on success, otherwise a negative errno.
+ */
+static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
+{
+ int time_left;
+
+ if (i2c->broken_irq_mode) {
+ /*
+ * Some cn38xx boards did not assert the irq in
+ * the interrupt controller. So we must poll for the
+ * IFLG change.
+ */
+ u64 end = get_jiffies_64() + i2c->adap.timeout;
+
+ while (!octeon_i2c_hlc_test_ready(i2c) &&
+ time_before64(get_jiffies_64(), end))
+ udelay(50);
+
+ return octeon_i2c_hlc_test_ready(i2c) ? 0 : -ETIMEDOUT;
+ }
+
+ i2c->hlc_int_en(i2c);
+ time_left = wait_event_interruptible_timeout(i2c->queue,
+ octeon_i2c_hlc_test_ready(i2c),
+ i2c->adap.timeout);
+ i2c->hlc_int_dis(i2c);
+ if (!time_left)
+ octeon_i2c_hlc_int_clear(i2c);
+
+ if (time_left <= 0 && i2c->broken_irq_check &&
+ octeon_i2c_hlc_test_ready(i2c)) {
+ dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
+ i2c->broken_irq_mode = true;
+ return 0;
+ }
+
+ if (!time_left) {
+ dev_dbg(i2c->dev, "%s: timeout\n", __func__);
+ return -ETIMEDOUT;
+ }
+ if (time_left < 0) {
+ dev_dbg(i2c->dev, "%s: wait interrupted\n", __func__);
+ return time_left;
+ }
+ return 0;
+}
+
+/**
+ * octeon_i2c_read - receive data from the bus via low-level controller
+ * @i2c: The struct octeon_i2c
+ * @target: Target address
+ * @data: Pointer to the location to store the data
+ * @rlength: Length of the data
+ * @phase: which phase of a combined operation.
+ * @recv_len: flag for length byte
+ *
+ * The address is sent over the bus, then the data is read.
+ *
+ * Returns 0 on success, otherwise a negative errno.
+ */
+static int octeon_i2c_read(struct octeon_i2c *i2c, int target, u8 *data,
+ u16 *rlength, bool first, bool last, bool recv_len)
+{
+ u8 ctl = TWSI_CTL_ENAB | TWSI_CTL_AAK;
+ int i, result, length = *rlength;
+ u8 tmp;
+
+ if (length < 1)
+ return -EINVAL;
+
+ result = octeon_i2c_start(i2c, first);
+ if (result)
+ return result;
+
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, (target << 1) | 1);
+
+ for (i = 0; i < length; ) {
+ tmp = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
+ result = octeon_i2c_lost_arb(tmp, !(ctl & TWSI_CTL_AAK));
+ if (result)
+ return result;
+
+ switch (tmp) {
+ case STAT_RXDATA_ACK:
+ case STAT_RXDATA_NAK:
+ data[i++] = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_DATA);
+ }
+
+
+ /* NAK last recv'd byte, as a no-more-please */
+ if (last && i == length - 1)
+ ctl &= ~TWSI_CTL_AAK;
+
+ /* clr iflg to allow next event */
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, ctl);
+ result = octeon_i2c_wait(i2c);
+ if (result)
+ return result;
+ if (recv_len && i == 0) {
+ if (data[i] > I2C_SMBUS_BLOCK_MAX + 1) {
+ dev_err(i2c->dev,
+ "%s: read len > I2C_SMBUS_BLOCK_MAX %d\n",
+ __func__, data[i]);
+ return -EPROTO;
+ }
+ length += data[i];
+ }
+ }
+ *rlength = length;
+ return 0;
+}
+
+/**
+ * octeon_i2c_write - send data to the bus via low-level controller
+ * @i2c: The struct octeon_i2c
+ * @target: Target address
+ * @data: Pointer to the data to be sent
+ * @length: Length of the data
+ * @last: is last msg in combined operation?
+ *
+ * The address is sent over the bus, then the data.
+ *
+ * Returns 0 on success, otherwise a negative errno.
+ */
+static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
+ const u8 *data, int length, int first, int last)
+{
+ int i, result;
+
+ result = octeon_i2c_start(i2c, first);
+ if (result)
+ return result;
+
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, target << 1);
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
+
+ result = octeon_i2c_wait(i2c);
+ if (result)
+ return result;
+
+ for (i = 0; i < length; i++) {
+ result = check_arb(i2c, false);
+ if (result)
+ return result;
+
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, data[i]);
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
+
+ result = octeon_i2c_wait(i2c);
+ if (result)
+ return result;
+ result = check_arb(i2c, false);
+ if (result)
+ return result;
+ }
+
+ return 0;
+}
+
+/* high-level-controller pure read of up to 8 bytes */
+static int octeon_i2c_simple_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+ int i, j, ret = 0;
+ u64 cmd;
+
+ octeon_i2c_enable_hlc(i2c);
+ cmd = SW_TWSI_V | SW_TWSI_R | SW_TWSI_SOVR;
+ /* SIZE */
+ cmd |= (u64) (msgs[0].len - 1) << SW_TWSI_SIZE_SHIFT;
+ /* A */
+ cmd |= (u64) (msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
+
+ if (msgs[0].flags & I2C_M_TEN)
+ cmd |= SW_TWSI_OP_10;
+ else
+ cmd |= SW_TWSI_OP_7;
+
+ octeon_i2c_hlc_int_clear(i2c);
+ __raw_writeq(cmd, i2c->twsi_base + SW_TWSI);
+
+ ret = octeon_i2c_hlc_wait(i2c);
+ if (ret)
+ goto err;
+
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+ if ((cmd & SW_TWSI_R) == 0)
+ return -EAGAIN;
+
+ for (i = 0, j = msgs[0].len - 1; i < msgs[0].len && i < 4; i++, j--)
+ msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
+
+ if (msgs[0].len > 4) {
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT);
+ for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--)
+ msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
+ }
+
+err:
+ return ret;
+}
+
+/* high-level-controller pure write of up to 8 bytes */
+static int octeon_i2c_simple_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+ int i, j, ret = 0;
+ u64 cmd;
+
+ octeon_i2c_enable_hlc(i2c);
+ octeon_i2c_hlc_int_clear(i2c);
+
+ ret = check_arb(i2c, false);
+ if (ret)
+ goto err;
+
+ cmd = SW_TWSI_V | SW_TWSI_SOVR;
+ /* SIZE */
+ cmd |= (u64) (msgs[0].len - 1) << SW_TWSI_SIZE_SHIFT;
+ /* A */
+ cmd |= (u64) (msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
+
+ if (msgs[0].flags & I2C_M_TEN)
+ cmd |= SW_TWSI_OP_10;
+ else
+ cmd |= SW_TWSI_OP_7;
+
+ for (i = 0, j = msgs[0].len - 1; i < msgs[0].len && i < 4; i++, j--)
+ cmd |= (u64)msgs[0].buf[j] << (8 * i);
+
+ if (msgs[0].len > 4) {
+ u64 ext = 0;
+
+ for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--)
+ ext |= (u64) msgs[0].buf[j] << (8 * i);
+ writeqflush(ext, i2c->twsi_base + SW_TWSI_EXT);
+ }
+
+ writeqflush(cmd, i2c->twsi_base + SW_TWSI);
+
+ ret = octeon_i2c_hlc_wait(i2c);
+ if (ret)
+ goto err;
+
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+ if ((cmd & SW_TWSI_R) == 0)
+ return -EAGAIN;
+
+ ret = check_arb(i2c, false);
+
+err:
+ return ret;
+}
+
+/* high-level-controller composite write+read, msg0=addr, msg1=data */
+static int octeon_i2c_ia_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+ int i, j, ret = 0;
+ u64 cmd;
+
+ octeon_i2c_enable_hlc(i2c);
+
+ cmd = SW_TWSI_V | SW_TWSI_R | SW_TWSI_SOVR;
+ /* SIZE */
+ cmd |= (u64)(msgs[1].len - 1) << SW_TWSI_SIZE_SHIFT;
+ /* A */
+ cmd |= (u64)(msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
+
+ if (msgs[0].flags & I2C_M_TEN)
+ cmd |= SW_TWSI_OP_10_IA;
+ else
+ cmd |= SW_TWSI_OP_7_IA;
+
+ if (msgs[0].len == 2) {
+ u64 ext = 0;
+
+ cmd |= SW_TWSI_EIA;
+ ext = (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
+ cmd |= (u64) msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
+ __raw_writeq(ext, i2c->twsi_base + SW_TWSI_EXT);
+ } else
+ cmd |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
+
+ octeon_i2c_hlc_int_clear(i2c);
+ writeqflush(cmd, i2c->twsi_base + SW_TWSI);
+
+ ret = octeon_i2c_hlc_wait(i2c);
+ if (ret)
+ goto err;
+
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
+ if ((cmd & SW_TWSI_R) == 0)
+ return -EAGAIN;
+
+ for (i = 0, j = msgs[1].len - 1; i < msgs[1].len && i < 4; i++, j--)
+ msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
+
+ if (msgs[1].len > 4) {
+ cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT);
+ for (i = 0; i < msgs[1].len - 4 && i < 4; i++, j--)
+ msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
+ }
+
+err:
+ return ret;
+}
+
+/* high-level-controller composite write+write, m[0]len<=2, m[1]len<=8 */
+static int octeon_i2c_ia_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+ bool set_ext = false;
+ int i, j, ret = 0;
+ u64 cmd, ext = 0;
+
+ octeon_i2c_enable_hlc(i2c);
+
+ cmd = SW_TWSI_V | SW_TWSI_SOVR;
+ /* SIZE */
+ cmd |= (u64) (msgs[1].len - 1) << SW_TWSI_SIZE_SHIFT;
+ /* A */
+ cmd |= (u64) (msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
+
+ if (msgs[0].flags & I2C_M_TEN)
+ cmd |= SW_TWSI_OP_10_IA;
+ else
+ cmd |= SW_TWSI_OP_7_IA;
+
+ if (msgs[0].len == 2) {
+ cmd |= SW_TWSI_EIA;
+ ext |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
+ set_ext = true;
+ cmd |= (u64) msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
+ } else
+ cmd |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
+
+ for (i = 0, j = msgs[1].len - 1; i < msgs[1].len && i < 4; i++, j--)
+ cmd |= (u64) msgs[1].buf[j] << (8 * i);
+
+ if (msgs[1].len > 4) {
+ for (i = 0; i < msgs[1].len - 4 && i < 4; i++, j--)
+ ext |= (u64)msgs[1].buf[j] << (8 * i);
+ set_ext = true;
+ }
+ if (set_ext)
+ writeqflush(ext, i2c->twsi_base + SW_TWSI_EXT);
+
+ octeon_i2c_hlc_int_clear(i2c);
+ writeqflush(cmd, i2c->twsi_base + SW_TWSI);
+
+ ret = octeon_i2c_hlc_wait(i2c);
+ if (ret)
+ goto err;
+
+ cmd = octeon_i2c_read_sw64(i2c, SW_TWSI_EOP_TWSI_STAT);
+ if ((cmd & SW_TWSI_R) == 0)
+ return -EAGAIN;
+ ret = octeon_i2c_lost_arb(cmd, false);
+
+err:
+ return ret;
+}
+
+/**
+ * octeon_i2c_xfer - The driver's master_xfer function
+ * @adap: Pointer to the i2c_adapter structure
+ * @msgs: Pointer to the messages to be processed
+ * @num: Length of the MSGS array
+ *
+ * Returns the number of messages processed, or a negative errno on failure.
+ */
+int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+ int num)
+{
+ struct octeon_i2c *i2c = i2c_get_adapdata(adap);
+ int i, ret = 0;
+
+ if (num == 1) {
+ if (msgs[0].len > 0 && msgs[0].len <= 8) {
+ if (msgs[0].flags & I2C_M_RD)
+ ret = octeon_i2c_simple_read(i2c, msgs);
+ else
+ ret = octeon_i2c_simple_write(i2c, msgs);
+ goto out;
+ }
+ } else if (num == 2) {
+ if ((msgs[0].flags & I2C_M_RD) == 0 &&
+ (msgs[1].flags & I2C_M_RECV_LEN) == 0 &&
+ msgs[0].len > 0 && msgs[0].len <= 2 &&
+ msgs[1].len > 0 && msgs[1].len <= 8 &&
+ msgs[0].addr == msgs[1].addr) {
+ if (msgs[1].flags & I2C_M_RD)
+ ret = octeon_i2c_ia_read(i2c, msgs);
+ else
+ ret = octeon_i2c_ia_write(i2c, msgs);
+ goto out;
+ }
+ }
+
+ for (i = 0; ret == 0 && i < num; i++) {
+ struct i2c_msg *pmsg = &msgs[i];
+ bool last = (i == (num - 1));
+
+ dev_dbg(i2c->dev,
+ "Doing %s %d byte(s) to/from 0x%02x - %d of %d messages\n",
+ pmsg->flags & I2C_M_RD ? "read" : "write",
+ pmsg->len, pmsg->addr, i + 1, num);
+ if (pmsg->flags & I2C_M_RD)
+ ret = octeon_i2c_read(i2c, pmsg->addr, pmsg->buf,
+ &pmsg->len, !i, last,
+ pmsg->flags & I2C_M_RECV_LEN);
+ else
+ ret = octeon_i2c_write(i2c, pmsg->addr, pmsg->buf,
+ pmsg->len, !i, last);
+ }
+ octeon_i2c_stop(i2c);
+out:
+ return (ret != 0) ? ret : num;
+}
+
+/* calculate and set clock divisors */
+void octeon_i2c_set_clock(struct octeon_i2c *i2c)
+{
+ int tclk, thp_base, inc, thp_idx, mdiv_idx, ndiv_idx, foscl, diff;
+ int thp = 0x18, mdiv = 2, ndiv = 0, delta_hz = 1000000;
+
+ for (ndiv_idx = 0; ndiv_idx < 8 && delta_hz != 0; ndiv_idx++) {
+ /*
+ * An mdiv value of less than 2 seems to not work well
+ * with ds1337 RTCs, so we constrain it to larger values.
+ */
+ for (mdiv_idx = 15; mdiv_idx >= 2 && delta_hz != 0; mdiv_idx--) {
+ /*
+ * For given ndiv and mdiv values check the
+ * two closest thp values.
+ */
+ tclk = i2c->twsi_freq * (mdiv_idx + 1) * 10;
+ tclk *= (1 << ndiv_idx);
+ thp_base = (i2c->sys_freq / (tclk * 2)) - 1;
+
+ for (inc = 0; inc <= 1; inc++) {
+ thp_idx = thp_base + inc;
+ if (thp_idx < 5 || thp_idx > 0xff)
+ continue;
+
+ foscl = i2c->sys_freq / (2 * (thp_idx + 1));
+ foscl = foscl / (1 << ndiv_idx);
+ foscl = foscl / (mdiv_idx + 1) / 10;
+ diff = abs(foscl - i2c->twsi_freq);
+ if (diff < delta_hz) {
+ delta_hz = diff;
+ thp = thp_idx;
+ mdiv = mdiv_idx;
+ ndiv = ndiv_idx;
+ }
+ }
+ }
+ }
+ octeon_i2c_write_sw(i2c, SW_TWSI_OP_TWSI_CLK, thp);
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CLKCTL, (mdiv << 3) | ndiv);
+}
+
+int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c)
+{
+ u8 status = 0;
+ int tries;
+
+ /* reset controller */
+ octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_RST, 0);
+
+ for (tries = 10; tries && status != STAT_IDLE; tries--) {
+ udelay(1);
+ status = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
+ }
+
+ if (status != STAT_IDLE) {
+ dev_err(i2c->dev, "%s: TWSI_RST failed! (0x%x)\n",
+ __func__, status);
+ return -EIO;
+ }
+
+ /* toggle twice to force both teardowns */
+ octeon_i2c_enable_hlc(i2c);
+ octeon_i2c_disable_hlc(i2c);
+ return 0;
+}
diff --git a/drivers/i2c/busses/i2c-cavium.h b/drivers/i2c/busses/i2c-cavium.h
new file mode 100644
index 0000000..7f78bf0
--- /dev/null
+++ b/drivers/i2c/busses/i2c-cavium.h
@@ -0,0 +1,195 @@
+#include <linux/atomic.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/pci.h>
+
+/* Register offsets */
+#define SW_TWSI 0x00
+#define TWSI_INT 0x10
+#define SW_TWSI_EXT 0x18
+
+/* Controller command patterns */
+#define SW_TWSI_V BIT_ULL(63) /* Valid bit */
+#define SW_TWSI_EIA BIT_ULL(61) /* Extended internal address */
+#define SW_TWSI_R BIT_ULL(56) /* Result or read bit */
+#define SW_TWSI_SOVR BIT_ULL(55) /* Size override */
+#define SW_TWSI_SIZE_SHIFT 52
+#define SW_TWSI_ADDR_SHIFT 40
+#define SW_TWSI_IA_SHIFT 32 /* Internal address */
+
+/* Controller opcode word (bits 60:57) */
+#define SW_TWSI_OP_SHIFT 57
+#define SW_TWSI_OP_7 (0ULL << SW_TWSI_OP_SHIFT)
+#define SW_TWSI_OP_7_IA (1ULL << SW_TWSI_OP_SHIFT)
+#define SW_TWSI_OP_10 (2ULL << SW_TWSI_OP_SHIFT)
+#define SW_TWSI_OP_10_IA (3ULL << SW_TWSI_OP_SHIFT)
+#define SW_TWSI_OP_TWSI_CLK (4ULL << SW_TWSI_OP_SHIFT)
+#define SW_TWSI_OP_EOP (6ULL << SW_TWSI_OP_SHIFT) /* Extended opcode */
+
+/* Controller extended opcode word (bits 34:32) */
+#define SW_TWSI_EOP_SHIFT 32
+#define SW_TWSI_EOP_TWSI_DATA (SW_TWSI_OP_EOP | 1ULL << SW_TWSI_EOP_SHIFT)
+#define SW_TWSI_EOP_TWSI_CTL (SW_TWSI_OP_EOP | 2ULL << SW_TWSI_EOP_SHIFT)
+#define SW_TWSI_EOP_TWSI_CLKCTL (SW_TWSI_OP_EOP | 3ULL << SW_TWSI_EOP_SHIFT)
+#define SW_TWSI_EOP_TWSI_STAT (SW_TWSI_OP_EOP | 3ULL << SW_TWSI_EOP_SHIFT)
+#define SW_TWSI_EOP_TWSI_RST (SW_TWSI_OP_EOP | 7ULL << SW_TWSI_EOP_SHIFT)
+
+/* Controller command and status bits */
+#define TWSI_CTL_CE 0x80 /* High level controller enable */
+#define TWSI_CTL_ENAB 0x40 /* Bus enable */
+#define TWSI_CTL_STA 0x20 /* Master-mode start, HW clears when done */
+#define TWSI_CTL_STP 0x10 /* Master-mode stop, HW clears when done */
+#define TWSI_CTL_IFLG 0x08 /* HW event, SW writes 0 to ACK */
+#define TWSI_CTL_AAK 0x04 /* Assert ACK */
+
+/* Some status values */
+#define STAT_ERROR 0x00
+#define STAT_START 0x08
+#define STAT_RSTART 0x10
+#define STAT_TXADDR_ACK 0x18
+#define STAT_TXADDR_NAK 0x20
+#define STAT_TXDATA_ACK 0x28
+#define STAT_TXDATA_NAK 0x30
+#define STAT_LOST_ARB_38 0x38
+#define STAT_RXADDR_ACK 0x40
+#define STAT_RXADDR_NAK 0x48
+#define STAT_RXDATA_ACK 0x50
+#define STAT_RXDATA_NAK 0x58
+#define STAT_SLAVE_60 0x60
+#define STAT_LOST_ARB_68 0x68
+#define STAT_SLAVE_70 0x70
+#define STAT_LOST_ARB_78 0x78
+#define STAT_SLAVE_80 0x80
+#define STAT_SLAVE_88 0x88
+#define STAT_GENDATA_ACK 0x90
+#define STAT_GENDATA_NAK 0x98
+#define STAT_SLAVE_A0 0xA0
+#define STAT_SLAVE_A8 0xA8
+#define STAT_LOST_ARB_B0 0xB0
+#define STAT_SLAVE_LOST 0xB8
+#define STAT_SLAVE_NAK 0xC0
+#define STAT_SLAVE_ACK 0xC8
+#define STAT_AD2W_ACK 0xD0
+#define STAT_AD2W_NAK 0xD8
+#define STAT_IDLE 0xF8
+
+/* TWSI_INT values */
+#define TWSI_INT_ST_INT BIT_ULL(0)
+#define TWSI_INT_TS_INT BIT_ULL(1)
+#define TWSI_INT_CORE_INT BIT_ULL(2)
+#define TWSI_INT_ST_EN BIT_ULL(4)
+#define TWSI_INT_TS_EN BIT_ULL(5)
+#define TWSI_INT_CORE_EN BIT_ULL(6)
+#define TWSI_INT_SDA_OVR BIT_ULL(8)
+#define TWSI_INT_SCL_OVR BIT_ULL(9)
+#define TWSI_INT_SDA BIT_ULL(10)
+#define TWSI_INT_SCL BIT_ULL(11)
+
+struct octeon_i2c {
+ wait_queue_head_t queue;
+ struct i2c_adapter adap;
+ int irq;
+ int hlc_irq; /* For cn7890 only */
+ u32 twsi_freq;
+ int sys_freq;
+ void __iomem *twsi_base;
+ struct device *dev;
+ bool hlc_enabled;
+ bool broken_irq_mode;
+ bool broken_irq_check;
+ void (*int_en)(struct octeon_i2c *);
+ void (*int_dis)(struct octeon_i2c *);
+ void (*hlc_int_en)(struct octeon_i2c *);
+ void (*hlc_int_dis)(struct octeon_i2c *);
+ atomic_t int_en_cnt;
+ atomic_t hlc_int_en_cnt;
+};
+
+static inline void writeqflush(u64 val, void __iomem *addr)
+{
+ __raw_writeq(val, addr);
+ __raw_readq(addr); /* wait for write to land */
+}
+
+/**
+ * octeon_i2c_write_sw - write an I2C core register
+ * @i2c: The struct octeon_i2c
+ * @eop_reg: Register selector
+ * @data: Value to be written
+ *
+ * The I2C core registers are accessed indirectly via the SW_TWSI CSR.
+ */
+static inline void octeon_i2c_write_sw(struct octeon_i2c *i2c, u64 eop_reg, u32 data)
+{
+ u64 tmp;
+
+ __raw_writeq(SW_TWSI_V | eop_reg | data, i2c->twsi_base + SW_TWSI);
+ do {
+ tmp = __raw_readq(i2c->twsi_base + SW_TWSI);
+ } while ((tmp & SW_TWSI_V) != 0);
+}
+
+/**
+ * octeon_i2c_read_sw64 - read an I2C core register
+ * @i2c: The struct octeon_i2c
+ * @eop_reg: Register selector
+ *
+ * Returns the data.
+ *
+ * The I2C core registers are accessed indirectly via the SW_TWSI CSR.
+ */
+static inline u64 octeon_i2c_read_sw64(struct octeon_i2c *i2c, u64 eop_reg)
+{
+ u64 tmp;
+
+ __raw_writeq(SW_TWSI_V | eop_reg | SW_TWSI_R, i2c->twsi_base + SW_TWSI);
+ do {
+ tmp = __raw_readq(i2c->twsi_base + SW_TWSI);
+ } while ((tmp & SW_TWSI_V) != 0);
+
+ return tmp;
+}
+
+/**
+ * octeon_i2c_read_sw - read lower bits of an I2C core register
+ * @i2c: The struct octeon_i2c
+ * @eop_reg: Register selector
+ *
+ * Returns the data.
+ *
+ * The I2C core registers are accessed indirectly via the SW_TWSI CSR.
+ */
+static inline u8 octeon_i2c_read_sw(struct octeon_i2c *i2c, u64 eop_reg)
+{
+ return octeon_i2c_read_sw64(i2c, eop_reg) & 0xFF;
+}
+
+/**
+ * octeon_i2c_write_int - write the TWSI_INT register
+ * @i2c: The struct octeon_i2c
+ * @data: Value to be written
+ */
+static inline void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data)
+{
+ writeqflush(data, i2c->twsi_base + TWSI_INT);
+}
+
+static inline u64 octeon_i2c_read_ctl(struct octeon_i2c *i2c)
+{
+ return octeon_i2c_read_sw64(i2c, SW_TWSI_EOP_TWSI_CTL);
+}
+
+static inline int octeon_i2c_test_iflg(struct octeon_i2c *i2c)
+{
+ return (octeon_i2c_read_ctl(i2c) & TWSI_CTL_IFLG) != 0;
+}
+
+/* Prototypes */
+irqreturn_t octeon_i2c_isr(int irq, void *dev_id);
+int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
+int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c);
+void octeon_i2c_set_clock(struct octeon_i2c *i2c);
diff --git a/drivers/i2c/busses/i2c-octeon-core.c b/drivers/i2c/busses/i2c-octeon-core.c
index 95cd301..87e7649 100644
--- a/drivers/i2c/busses/i2c-octeon-core.c
+++ b/drivers/i2c/busses/i2c-octeon-core.c
@@ -24,182 +24,10 @@
#include <linux/of.h>
#include <asm/octeon/octeon.h>
+#include "i2c-cavium.h"
#define DRV_NAME "i2c-octeon"
-/* Register offsets */
-#define SW_TWSI 0x00
-#define TWSI_INT 0x10
-#define SW_TWSI_EXT 0x18
-
-/* Controller command patterns */
-#define SW_TWSI_V BIT_ULL(63) /* Valid bit */
-#define SW_TWSI_EIA BIT_ULL(61) /* Extended internal address */
-#define SW_TWSI_R BIT_ULL(56) /* Result or read bit */
-#define SW_TWSI_SOVR BIT_ULL(55) /* Size override */
-#define SW_TWSI_SIZE_SHIFT 52
-#define SW_TWSI_ADDR_SHIFT 40
-#define SW_TWSI_IA_SHIFT 32 /* Internal address */
-
-/* Controller opcode word (bits 60:57) */
-#define SW_TWSI_OP_SHIFT 57
-#define SW_TWSI_OP_7 (0ULL << SW_TWSI_OP_SHIFT)
-#define SW_TWSI_OP_7_IA (1ULL << SW_TWSI_OP_SHIFT)
-#define SW_TWSI_OP_10 (2ULL << SW_TWSI_OP_SHIFT)
-#define SW_TWSI_OP_10_IA (3ULL << SW_TWSI_OP_SHIFT)
-#define SW_TWSI_OP_TWSI_CLK (4ULL << SW_TWSI_OP_SHIFT)
-#define SW_TWSI_OP_EOP (6ULL << SW_TWSI_OP_SHIFT) /* Extended opcode */
-
-/* Controller extended opcode word (bits 34:32) */
-#define SW_TWSI_EOP_SHIFT 32
-#define SW_TWSI_EOP_TWSI_DATA (SW_TWSI_OP_EOP | 1ULL << SW_TWSI_EOP_SHIFT)
-#define SW_TWSI_EOP_TWSI_CTL (SW_TWSI_OP_EOP | 2ULL << SW_TWSI_EOP_SHIFT)
-#define SW_TWSI_EOP_TWSI_CLKCTL (SW_TWSI_OP_EOP | 3ULL << SW_TWSI_EOP_SHIFT)
-#define SW_TWSI_EOP_TWSI_STAT (SW_TWSI_OP_EOP | 3ULL << SW_TWSI_EOP_SHIFT)
-#define SW_TWSI_EOP_TWSI_RST (SW_TWSI_OP_EOP | 7ULL << SW_TWSI_EOP_SHIFT)
-
-/* Controller command and status bits */
-#define TWSI_CTL_CE 0x80 /* High level controller enable */
-#define TWSI_CTL_ENAB 0x40 /* Bus enable */
-#define TWSI_CTL_STA 0x20 /* Master-mode start, HW clears when done */
-#define TWSI_CTL_STP 0x10 /* Master-mode stop, HW clears when done */
-#define TWSI_CTL_IFLG 0x08 /* HW event, SW writes 0 to ACK */
-#define TWSI_CTL_AAK 0x04 /* Assert ACK */
-
-/* Some status values */
-#define STAT_ERROR 0x00
-#define STAT_START 0x08
-#define STAT_RSTART 0x10
-#define STAT_TXADDR_ACK 0x18
-#define STAT_TXADDR_NAK 0x20
-#define STAT_TXDATA_ACK 0x28
-#define STAT_TXDATA_NAK 0x30
-#define STAT_LOST_ARB_38 0x38
-#define STAT_RXADDR_ACK 0x40
-#define STAT_RXADDR_NAK 0x48
-#define STAT_RXDATA_ACK 0x50
-#define STAT_RXDATA_NAK 0x58
-#define STAT_SLAVE_60 0x60
-#define STAT_LOST_ARB_68 0x68
-#define STAT_SLAVE_70 0x70
-#define STAT_LOST_ARB_78 0x78
-#define STAT_SLAVE_80 0x80
-#define STAT_SLAVE_88 0x88
-#define STAT_GENDATA_ACK 0x90
-#define STAT_GENDATA_NAK 0x98
-#define STAT_SLAVE_A0 0xA0
-#define STAT_SLAVE_A8 0xA8
-#define STAT_LOST_ARB_B0 0xB0
-#define STAT_SLAVE_LOST 0xB8
-#define STAT_SLAVE_NAK 0xC0
-#define STAT_SLAVE_ACK 0xC8
-#define STAT_AD2W_ACK 0xD0
-#define STAT_AD2W_NAK 0xD8
-#define STAT_IDLE 0xF8
-
-/* TWSI_INT values */
-#define TWSI_INT_ST_INT BIT_ULL(0)
-#define TWSI_INT_TS_INT BIT_ULL(1)
-#define TWSI_INT_CORE_INT BIT_ULL(2)
-#define TWSI_INT_ST_EN BIT_ULL(4)
-#define TWSI_INT_TS_EN BIT_ULL(5)
-#define TWSI_INT_CORE_EN BIT_ULL(6)
-#define TWSI_INT_SDA_OVR BIT_ULL(8)
-#define TWSI_INT_SCL_OVR BIT_ULL(9)
-#define TWSI_INT_SDA BIT_ULL(10)
-#define TWSI_INT_SCL BIT_ULL(11)
-
-struct octeon_i2c {
- wait_queue_head_t queue;
- struct i2c_adapter adap;
- int irq;
- int hlc_irq; /* For cn7890 only */
- u32 twsi_freq;
- int sys_freq;
- void __iomem *twsi_base;
- struct device *dev;
- bool hlc_enabled;
- bool broken_irq_mode;
- bool broken_irq_check;
- void (*int_en)(struct octeon_i2c *);
- void (*int_dis)(struct octeon_i2c *);
- void (*hlc_int_en)(struct octeon_i2c *);
- void (*hlc_int_dis)(struct octeon_i2c *);
- atomic_t int_en_cnt;
- atomic_t hlc_int_en_cnt;
-};
-
-static int reset_how;
-
-static void writeqflush(u64 val, void __iomem *addr)
-{
- __raw_writeq(val, addr);
- __raw_readq(addr); /* wait for write to land */
-}
-
-/**
- * octeon_i2c_write_sw - write an I2C core register
- * @i2c: The struct octeon_i2c
- * @eop_reg: Register selector
- * @data: Value to be written
- *
- * The I2C core registers are accessed indirectly via the SW_TWSI CSR.
- */
-static void octeon_i2c_write_sw(struct octeon_i2c *i2c, u64 eop_reg, u32 data)
-{
- u64 tmp;
-
- __raw_writeq(SW_TWSI_V | eop_reg | data, i2c->twsi_base + SW_TWSI);
- do {
- tmp = __raw_readq(i2c->twsi_base + SW_TWSI);
- } while ((tmp & SW_TWSI_V) != 0);
-}
-
-/**
- * octeon_i2c_read_sw64 - read an I2C core register
- * @i2c: The struct octeon_i2c
- * @eop_reg: Register selector
- *
- * Returns the data.
- *
- * The I2C core registers are accessed indirectly via the SW_TWSI CSR.
- */
-static u64 octeon_i2c_read_sw64(struct octeon_i2c *i2c, u64 eop_reg)
-{
- u64 tmp;
-
- __raw_writeq(SW_TWSI_V | eop_reg | SW_TWSI_R, i2c->twsi_base + SW_TWSI);
- do {
- tmp = __raw_readq(i2c->twsi_base + SW_TWSI);
- } while ((tmp & SW_TWSI_V) != 0);
-
- return tmp;
-}
-
-/**
- * octeon_i2c_read_sw - read lower bits of an I2C core register
- * @i2c: The struct octeon_i2c
- * @eop_reg: Register selector
- *
- * Returns the data.
- *
- * The I2C core registers are accessed indirectly via the SW_TWSI CSR.
- */
-static u8 octeon_i2c_read_sw(struct octeon_i2c *i2c, u64 eop_reg)
-{
- return octeon_i2c_read_sw64(i2c, eop_reg) & 0xFF;
-}
-
-/**
- * octeon_i2c_write_int - write the TWSI_INT register
- * @i2c: The struct octeon_i2c
- * @data: Value to be written
- */
-static void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data)
-{
- writeqflush(data, i2c->twsi_base + TWSI_INT);
-}
-
/**
* octeon_i2c_int_enable - enable the CORE interrupt
* @i2c: The struct octeon_i2c
@@ -219,15 +47,6 @@ static void octeon_i2c_int_disable(struct octeon_i2c *i2c)
octeon_i2c_write_int(i2c, 0);
}
-static void octeon_i2c_disable_hlc(struct octeon_i2c *i2c)
-{
- if (!i2c->hlc_enabled)
- return;
-
- i2c->hlc_enabled = false;
- octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
-}
-
/**
* octeon_i2c_int_enable78 - enable the CORE interrupt
* @i2c: The struct octeon_i2c
@@ -280,49 +99,6 @@ static void octeon_i2c_hlc_int_disable78(struct octeon_i2c *i2c)
__octeon_i2c_irq_disable(&i2c->hlc_int_en_cnt, i2c->hlc_irq);
}
-/**
- * octeon_i2c_unblock - unblock the bus
- * @i2c: The struct octeon_i2c
- *
- * If there was a reset while a device was driving 0 to bus, bus is blocked.
- * We toggle it free manually by some clock cycles and send a stop.
- */
-static void octeon_i2c_unblock(struct octeon_i2c *i2c)
-{
- int state, i;
-
- octeon_i2c_disable_hlc(i2c);
- dev_dbg(i2c->dev, "%s\n", __func__);
-
- /* cycle 8+1 clocks with SDA high */
- for (i = 0; i < 9; i++) {
- octeon_i2c_write_int(i2c, 0);
- udelay(5);
- state = __raw_readq(i2c->twsi_base + TWSI_INT);
- if (state & (TWSI_INT_SDA | TWSI_INT_SCL))
- break;
- octeon_i2c_write_int(i2c, TWSI_INT_SCL_OVR);
- udelay(5);
- }
- /* hand-crank a STOP */
- octeon_i2c_write_int(i2c, TWSI_INT_SDA_OVR | TWSI_INT_SCL_OVR);
- udelay(5);
- octeon_i2c_write_int(i2c, TWSI_INT_SDA_OVR);
- udelay(5);
- octeon_i2c_write_int(i2c, 0);
-}
-
-/* interrupt service routine */
-static irqreturn_t octeon_i2c_isr(int irq, void *dev_id)
-{
- struct octeon_i2c *i2c = dev_id;
-
- i2c->int_dis(i2c);
- wake_up(&i2c->queue);
-
- return IRQ_HANDLED;
-}
-
/* HLC interrupt service routine */
static irqreturn_t octeon_i2c_hlc_isr78(int irq, void *dev_id)
{
@@ -334,768 +110,11 @@ static irqreturn_t octeon_i2c_hlc_isr78(int irq, void *dev_id)
return IRQ_HANDLED;
}
-static u64 octeon_i2c_read_ctl(struct octeon_i2c *i2c)
-{
- return octeon_i2c_read_sw64(i2c, SW_TWSI_EOP_TWSI_CTL);
-}
-
-static int octeon_i2c_test_iflg(struct octeon_i2c *i2c)
-{
- return (octeon_i2c_read_ctl(i2c) & TWSI_CTL_IFLG) != 0;
-}
-
-#define I2C_OCTEON_IFLG_WAIT 80 /* microseconds */
-
-/*
- * Wait-helper which addresses the delayed-IFLAG problem by re-polling for
- * missing TWSI_CTL[IFLG] a few us later, when irq has signalled an event,
- * but none found. Skip this re-poll on the first (non-wakeup) call.
- */
-static int poll_iflg(struct octeon_i2c *i2c, int *first_p)
-{
- int iflg = octeon_i2c_test_iflg(i2c);
-
- if (iflg)
- return 1;
- if (*first_p)
- *first_p = 0;
- else {
- usleep_range(I2C_OCTEON_IFLG_WAIT, 2 * I2C_OCTEON_IFLG_WAIT);
- iflg = octeon_i2c_test_iflg(i2c);
- }
- return iflg;
-}
-
-/**
- * octeon_i2c_wait - wait for the IFLG to be set
- * @i2c: The struct octeon_i2c
- *
- * Returns 0 on success, otherwise a negative errno.
- */
-static int octeon_i2c_wait(struct octeon_i2c *i2c)
-{
- long time_left;
- int first = 1;
-
- if (i2c->broken_irq_mode) {
- /*
- * Some chip revisions seem to not assert the irq in
- * the interrupt controller. So we must poll for the
- * IFLG change.
- */
- u64 end = get_jiffies_64() + i2c->adap.timeout;
-
- while (!octeon_i2c_test_iflg(i2c) &&
- time_before64(get_jiffies_64(), end))
- udelay(50);
-
- return octeon_i2c_test_iflg(i2c) ? 0 : -ETIMEDOUT;
- }
-
- i2c->int_en(i2c);
- time_left = wait_event_timeout(i2c->queue, poll_iflg(i2c, &first),
- i2c->adap.timeout);
- i2c->int_dis(i2c);
-
- if (time_left <= 0 && i2c->broken_irq_check &&
- octeon_i2c_test_iflg(i2c)) {
- dev_err(i2c->dev,
- "broken irq connection detected, switching to polling mode.\n");
- i2c->broken_irq_mode = true;
- return 0;
- }
- if (!time_left) {
- dev_dbg(i2c->dev, "%s: timeout\n", __func__);
- return -ETIMEDOUT;
- }
-
- return 0;
-}
-
-/*
- * Cleanup low-level state & enable high-level.
- * Returns -EAGAIN if low-level state could not be cleaned.
- */
-static int octeon_i2c_enable_hlc(struct octeon_i2c *i2c)
-{
- int try = 0, ret = 0;
- u64 val;
-
- if (i2c->hlc_enabled)
- return 0;
- i2c->hlc_enabled = true;
-
- while (1) {
- val = octeon_i2c_read_ctl(i2c) & (TWSI_CTL_STA | TWSI_CTL_STP);
- if (!val)
- break;
-
- /* clear IFLG event */
- if (val & TWSI_CTL_IFLG)
- octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
-
- if (try++ > 100) {
- pr_err("%s: giving up\n", __func__);
- ret = -EAGAIN;
- break;
- }
-
- /* spin until any start/stop has finished */
- udelay(10);
- }
-
- octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
- TWSI_CTL_CE | TWSI_CTL_AAK | TWSI_CTL_ENAB);
- return ret;
-}
-
-static int octeon_i2c_lost_arb(u8 code, int final_read)
-{
- switch (code) {
- /* Arbitration lost */
- case STAT_LOST_ARB_38:
- case STAT_LOST_ARB_68:
- case STAT_LOST_ARB_78:
- case STAT_LOST_ARB_B0:
- return -EAGAIN;
-
- /* Being addressed as slave, should back off & listen */
- case STAT_SLAVE_60:
- case STAT_SLAVE_70:
- case STAT_GENDATA_ACK:
- case STAT_GENDATA_NAK:
- return -EIO;
-
- /* Core busy as slave */
- case STAT_SLAVE_80:
- case STAT_SLAVE_88:
- case STAT_SLAVE_A0:
- case STAT_SLAVE_A8:
- case STAT_SLAVE_LOST:
- case STAT_SLAVE_NAK:
- case STAT_SLAVE_ACK:
- return -EIO;
-
- /* ACK allowed on pre-terminal bytes only */
- case STAT_RXDATA_ACK:
- if (!final_read)
- return 0;
- return -EAGAIN;
-
- /* NAK allowed on terminal byte only */
- case STAT_RXDATA_NAK:
- if (final_read)
- return 0;
- return -EAGAIN;
- case STAT_TXDATA_NAK:
- case STAT_TXADDR_NAK:
- case STAT_RXADDR_NAK:
- case STAT_AD2W_NAK:
- return -EAGAIN;
- }
- return 0;
-}
-
-static int check_arb(struct octeon_i2c *i2c, int final_read)
-{
- return octeon_i2c_lost_arb(octeon_i2c_read_sw(i2c,
- SW_TWSI_EOP_TWSI_STAT), final_read);
-}
-
-/* send STOP to the bus */
-static void octeon_i2c_stop(struct octeon_i2c *i2c)
-{
- octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
- TWSI_CTL_ENAB | TWSI_CTL_STP);
-}
-
-static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c)
-{
- u64 val = __raw_readq(i2c->twsi_base + SW_TWSI);
-
- return (val & SW_TWSI_V) == 0;
-}
-
static void octeon_i2c_hlc_int_enable(struct octeon_i2c *i2c)
{
octeon_i2c_write_int(i2c, TWSI_INT_ST_EN);
}
-static void octeon_i2c_hlc_int_clear(struct octeon_i2c *i2c)
-{
- /* clear ST/TS events, listen for neither */
- octeon_i2c_write_int(i2c, TWSI_INT_ST_INT | TWSI_INT_TS_INT);
-}
-
-/**
- * octeon_i2c_hlc_wait - wait for an HLC operation to complete
- * @i2c: The struct octeon_i2c
- *
- * Returns 0 on success, otherwise a negative errno.
- */
-static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
-{
- int time_left;
-
- if (i2c->broken_irq_mode) {
- /*
- * Some cn38xx boards did not assert the irq in
- * the interrupt controller. So we must poll for the
- * IFLG change.
- */
- u64 end = get_jiffies_64() + i2c->adap.timeout;
-
- while (!octeon_i2c_hlc_test_ready(i2c) &&
- time_before64(get_jiffies_64(), end))
- udelay(50);
-
- return octeon_i2c_hlc_test_ready(i2c) ? 0 : -ETIMEDOUT;
- }
-
- i2c->hlc_int_en(i2c);
- time_left = wait_event_interruptible_timeout(i2c->queue,
- octeon_i2c_hlc_test_ready(i2c),
- i2c->adap.timeout);
- i2c->hlc_int_dis(i2c);
- if (!time_left)
- octeon_i2c_hlc_int_clear(i2c);
-
- if (time_left <= 0 && i2c->broken_irq_check &&
- octeon_i2c_hlc_test_ready(i2c)) {
- dev_err(i2c->dev, "broken irq connection detected, switching to polling mode.\n");
- i2c->broken_irq_mode = true;
- return 0;
- }
-
- if (!time_left) {
- dev_dbg(i2c->dev, "%s: timeout\n", __func__);
- return -ETIMEDOUT;
- }
- if (time_left < 0) {
- dev_dbg(i2c->dev, "%s: wait interrupted\n", __func__);
- return time_left;
- }
- return 0;
-}
-
-/* high-level-controller pure read of up to 8 bytes */
-static int octeon_i2c_simple_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
-{
- int i, j, ret = 0;
- u64 cmd;
-
- octeon_i2c_enable_hlc(i2c);
- cmd = SW_TWSI_V | SW_TWSI_R | SW_TWSI_SOVR;
- /* SIZE */
- cmd |= (u64) (msgs[0].len - 1) << SW_TWSI_SIZE_SHIFT;
- /* A */
- cmd |= (u64) (msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
-
- if (msgs[0].flags & I2C_M_TEN)
- cmd |= SW_TWSI_OP_10;
- else
- cmd |= SW_TWSI_OP_7;
-
- octeon_i2c_hlc_int_clear(i2c);
- __raw_writeq(cmd, i2c->twsi_base + SW_TWSI);
-
- ret = octeon_i2c_hlc_wait(i2c);
- if (ret)
- goto err;
-
- cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
- if ((cmd & SW_TWSI_R) == 0)
- return -EAGAIN;
-
- for (i = 0, j = msgs[0].len - 1; i < msgs[0].len && i < 4; i++, j--)
- msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
-
- if (msgs[0].len > 4) {
- cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT);
- for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--)
- msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
- }
-
-err:
- return ret;
-}
-
-/* high-level-controller pure write of up to 8 bytes */
-static int octeon_i2c_simple_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
-{
- int i, j, ret = 0;
- u64 cmd;
-
- octeon_i2c_enable_hlc(i2c);
- octeon_i2c_hlc_int_clear(i2c);
-
- ret = check_arb(i2c, false);
- if (ret)
- goto err;
-
- cmd = SW_TWSI_V | SW_TWSI_SOVR;
- /* SIZE */
- cmd |= (u64) (msgs[0].len - 1) << SW_TWSI_SIZE_SHIFT;
- /* A */
- cmd |= (u64) (msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
-
- if (msgs[0].flags & I2C_M_TEN)
- cmd |= SW_TWSI_OP_10;
- else
- cmd |= SW_TWSI_OP_7;
-
- for (i = 0, j = msgs[0].len - 1; i < msgs[0].len && i < 4; i++, j--)
- cmd |= (u64)msgs[0].buf[j] << (8 * i);
-
- if (msgs[0].len > 4) {
- u64 ext = 0;
-
- for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--)
- ext |= (u64) msgs[0].buf[j] << (8 * i);
- writeqflush(ext, i2c->twsi_base + SW_TWSI_EXT);
- }
-
- writeqflush(cmd, i2c->twsi_base + SW_TWSI);
-
- ret = octeon_i2c_hlc_wait(i2c);
- if (ret)
- goto err;
-
- cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
- if ((cmd & SW_TWSI_R) == 0)
- return -EAGAIN;
-
- ret = check_arb(i2c, false);
-
-err:
- return ret;
-}
-
-/* high-level-controller composite write+read, msg0=addr, msg1=data */
-static int octeon_i2c_ia_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
-{
- int i, j, ret = 0;
- u64 cmd;
-
- octeon_i2c_enable_hlc(i2c);
-
- cmd = SW_TWSI_V | SW_TWSI_R | SW_TWSI_SOVR;
- /* SIZE */
- cmd |= (u64)(msgs[1].len - 1) << SW_TWSI_SIZE_SHIFT;
- /* A */
- cmd |= (u64)(msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
-
- if (msgs[0].flags & I2C_M_TEN)
- cmd |= SW_TWSI_OP_10_IA;
- else
- cmd |= SW_TWSI_OP_7_IA;
-
- if (msgs[0].len == 2) {
- u64 ext = 0;
-
- cmd |= SW_TWSI_EIA;
- ext = (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
- cmd |= (u64) msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
- __raw_writeq(ext, i2c->twsi_base + SW_TWSI_EXT);
- } else
- cmd |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
-
- octeon_i2c_hlc_int_clear(i2c);
- writeqflush(cmd, i2c->twsi_base + SW_TWSI);
-
- ret = octeon_i2c_hlc_wait(i2c);
- if (ret)
- goto err;
-
- cmd = __raw_readq(i2c->twsi_base + SW_TWSI);
- if ((cmd & SW_TWSI_R) == 0)
- return -EAGAIN;
-
- for (i = 0, j = msgs[1].len - 1; i < msgs[1].len && i < 4; i++, j--)
- msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
-
- if (msgs[1].len > 4) {
- cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT);
- for (i = 0; i < msgs[1].len - 4 && i < 4; i++, j--)
- msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
- }
-
-err:
- return ret;
-}
-
-/* high-level-controller composite write+write, m[0]len<=2, m[1]len<=8 */
-static int octeon_i2c_ia_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
-{
- bool set_ext = false;
- int i, j, ret = 0;
- u64 cmd, ext = 0;
-
- octeon_i2c_enable_hlc(i2c);
-
- cmd = SW_TWSI_V | SW_TWSI_SOVR;
- /* SIZE */
- cmd |= (u64) (msgs[1].len - 1) << SW_TWSI_SIZE_SHIFT;
- /* A */
- cmd |= (u64) (msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
-
- if (msgs[0].flags & I2C_M_TEN)
- cmd |= SW_TWSI_OP_10_IA;
- else
- cmd |= SW_TWSI_OP_7_IA;
-
- if (msgs[0].len == 2) {
- cmd |= SW_TWSI_EIA;
- ext |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
- set_ext = true;
- cmd |= (u64) msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
- } else
- cmd |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
-
- for (i = 0, j = msgs[1].len - 1; i < msgs[1].len && i < 4; i++, j--)
- cmd |= (u64) msgs[1].buf[j] << (8 * i);
-
- if (msgs[1].len > 4) {
- for (i = 0; i < msgs[1].len - 4 && i < 4; i++, j--)
- ext |= (u64)msgs[1].buf[j] << (8 * i);
- set_ext = true;
- }
- if (set_ext)
- writeqflush(ext, i2c->twsi_base + SW_TWSI_EXT);
-
- octeon_i2c_hlc_int_clear(i2c);
- writeqflush(cmd, i2c->twsi_base + SW_TWSI);
-
- ret = octeon_i2c_hlc_wait(i2c);
- if (ret)
- goto err;
-
- cmd = octeon_i2c_read_sw64(i2c, SW_TWSI_EOP_TWSI_STAT);
- if ((cmd & SW_TWSI_R) == 0)
- return -EAGAIN;
- ret = octeon_i2c_lost_arb(cmd, false);
-
-err:
- return ret;
-}
-
-/* calculate and set clock divisors */
-static void octeon_i2c_set_clock(struct octeon_i2c *i2c)
-{
- int tclk, thp_base, inc, thp_idx, mdiv_idx, ndiv_idx, foscl, diff;
- int thp = 0x18, mdiv = 2, ndiv = 0, delta_hz = 1000000;
-
- for (ndiv_idx = 0; ndiv_idx < 8 && delta_hz != 0; ndiv_idx++) {
- /*
- * An mdiv value of less than 2 seems to not work well
- * with ds1337 RTCs, so we constrain it to larger values.
- */
- for (mdiv_idx = 15; mdiv_idx >= 2 && delta_hz != 0; mdiv_idx--) {
- /*
- * For given ndiv and mdiv values check the
- * two closest thp values.
- */
- tclk = i2c->twsi_freq * (mdiv_idx + 1) * 10;
- tclk *= (1 << ndiv_idx);
- thp_base = (i2c->sys_freq / (tclk * 2)) - 1;
-
- for (inc = 0; inc <= 1; inc++) {
- thp_idx = thp_base + inc;
- if (thp_idx < 5 || thp_idx > 0xff)
- continue;
-
- foscl = i2c->sys_freq / (2 * (thp_idx + 1));
- foscl = foscl / (1 << ndiv_idx);
- foscl = foscl / (mdiv_idx + 1) / 10;
- diff = abs(foscl - i2c->twsi_freq);
- if (diff < delta_hz) {
- delta_hz = diff;
- thp = thp_idx;
- mdiv = mdiv_idx;
- ndiv = ndiv_idx;
- }
- }
- }
- }
- octeon_i2c_write_sw(i2c, SW_TWSI_OP_TWSI_CLK, thp);
- octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CLKCTL, (mdiv << 3) | ndiv);
-}
-
-static int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c)
-{
- u8 status = 0;
- int tries;
-
- /* reset controller */
- octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_RST, 0);
-
- for (tries = 10; tries && status != STAT_IDLE; tries--) {
- udelay(1);
- status = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
- }
-
- if (status != STAT_IDLE) {
- dev_err(i2c->dev, "%s: TWSI_RST failed! (0x%x)\n",
- __func__, status);
- return -EIO;
- }
-
- /* toggle twice to force both teardowns */
- octeon_i2c_enable_hlc(i2c);
- octeon_i2c_disable_hlc(i2c);
- return 0;
-}
-
-/*
- * TWSI state seems stuck. Not sure if it's TWSI-engine state or something
- * else on bus. The initial _stop() is always harmless, it just resets state
- * machine, does not _transmit_ STOP unless engine was active.
- */
-static int start_unstick(struct octeon_i2c *i2c)
-{
- octeon_i2c_stop(i2c);
-
- /*
- * Response is escalated over successive calls,
- * as EAGAIN provokes retries from i2c/core.
- */
- switch (reset_how++ % 4) {
- case 0:
- /* just the stop above */
- break;
- case 1:
- /*
- * Controller refused to send start flag. May be a
- * client is holding SDA low? Let's try to free it.
- */
- octeon_i2c_unblock(i2c);
- break;
- case 2:
- /* re-init our TWSI hardware */
- octeon_i2c_init_lowlevel(i2c);
- break;
- default:
- /* retry in caller */
- reset_how = 0;
- return -EAGAIN;
- }
- return 0;
-}
-
-/**
- * octeon_i2c_start - send START to the bus
- * @i2c: The struct octeon_i2c
- * @first: first msg in combined operation?
- *
- * Returns 0 on success, otherwise a negative errno.
- */
-static int octeon_i2c_start(struct octeon_i2c *i2c, int first)
-{
- int result;
- u8 data;
-
- octeon_i2c_disable_hlc(i2c);
-
- while (1) {
- octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL,
- TWSI_CTL_ENAB | TWSI_CTL_STA);
-
- result = octeon_i2c_wait(i2c);
- data = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
-
- switch (data) {
- case STAT_START:
- case STAT_RSTART:
- if (!first)
- return -EAGAIN;
- reset_how = 0;
- return 0;
- case STAT_RXADDR_ACK:
- if (first)
- return -EAGAIN;
- return start_unstick(i2c);
- /*
- * case STAT_IDLE:
- * case STAT_ERROR:
- */
- default:
- if (!first)
- return -EAGAIN;
- start_unstick(i2c);
- }
- }
- return 0;
-}
-
-/**
- * octeon_i2c_read - receive data from the bus via low-level controller
- * @i2c: The struct octeon_i2c
- * @target: Target address
- * @data: Pointer to the location to store the data
- * @rlength: Length of the data
- * @phase: which phase of a combined operation.
- * @recv_len: flag for length byte
- *
- * The address is sent over the bus, then the data is read.
- *
- * Returns 0 on success, otherwise a negative errno.
- */
-static int octeon_i2c_read(struct octeon_i2c *i2c, int target, u8 *data,
- u16 *rlength, bool first, bool last, bool recv_len)
-{
- u8 ctl = TWSI_CTL_ENAB | TWSI_CTL_AAK;
- int i, result, length = *rlength;
- u8 tmp;
-
- if (length < 1)
- return -EINVAL;
-
- result = octeon_i2c_start(i2c, first);
- if (result)
- return result;
-
- octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, (target << 1) | 1);
-
- for (i = 0; i < length; ) {
- tmp = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_STAT);
- result = octeon_i2c_lost_arb(tmp, !(ctl & TWSI_CTL_AAK));
- if (result)
- return result;
-
- switch (tmp) {
- case STAT_RXDATA_ACK:
- case STAT_RXDATA_NAK:
- data[i++] = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_DATA);
- }
-
- /* NAK last recv'd byte, as a no-more-please */
- if (last && i == length - 1)
- ctl &= ~TWSI_CTL_AAK;
-
- /* clr iflg to allow next event */
- octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, ctl);
- result = octeon_i2c_wait(i2c);
- if (result)
- return result;
-
- if (recv_len && i == 0) {
- if (data[i] > I2C_SMBUS_BLOCK_MAX + 1) {
- dev_err(i2c->dev,
- "%s: read len > I2C_SMBUS_BLOCK_MAX %d\n",
- __func__, data[i]);
- return -EPROTO;
- }
- length += data[i];
- }
- }
- *rlength = length;
- return 0;
-}
-
-/**
- * octeon_i2c_write - send data to the bus via low-level controller
- * @i2c: The struct octeon_i2c
- * @target: Target address
- * @data: Pointer to the data to be sent
- * @length: Length of the data
- * @last: is last msg in combined operation?
- *
- * The address is sent over the bus, then the data.
- *
- * Returns 0 on success, otherwise a negative errno.
- */
-static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
- const u8 *data, int length, int first, int last)
-{
- int i, result;
-
- result = octeon_i2c_start(i2c, first);
- if (result)
- return result;
-
- octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, target << 1);
- octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
-
- result = octeon_i2c_wait(i2c);
- if (result)
- return result;
-
- for (i = 0; i < length; i++) {
- result = check_arb(i2c, false);
- if (result)
- return result;
-
- octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_DATA, data[i]);
- octeon_i2c_write_sw(i2c, SW_TWSI_EOP_TWSI_CTL, TWSI_CTL_ENAB);
-
- result = octeon_i2c_wait(i2c);
- if (result)
- return result;
- result = check_arb(i2c, false);
- if (result)
- return result;
- }
-
- return 0;
-}
-
-/**
- * octeon_i2c_xfer - The driver's master_xfer function
- * @adap: Pointer to the i2c_adapter structure
- * @msgs: Pointer to the messages to be processed
- * @num: Length of the MSGS array
- *
- * Returns the number of messages processed, or a negative errno on failure.
- */
-static int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
- int num)
-{
- struct octeon_i2c *i2c = i2c_get_adapdata(adap);
- int i, ret = 0;
-
- if (num == 1) {
- if (msgs[0].len > 0 && msgs[0].len <= 8) {
- if (msgs[0].flags & I2C_M_RD)
- ret = octeon_i2c_simple_read(i2c, msgs);
- else
- ret = octeon_i2c_simple_write(i2c, msgs);
- goto out;
- }
- } else if (num == 2) {
- if ((msgs[0].flags & I2C_M_RD) == 0 &&
- (msgs[1].flags & I2C_M_RECV_LEN) == 0 &&
- msgs[0].len > 0 && msgs[0].len <= 2 &&
- msgs[1].len > 0 && msgs[1].len <= 8 &&
- msgs[0].addr == msgs[1].addr) {
- if (msgs[1].flags & I2C_M_RD)
- ret = octeon_i2c_ia_read(i2c, msgs);
- else
- ret = octeon_i2c_ia_write(i2c, msgs);
- goto out;
- }
- }
-
- for (i = 0; ret == 0 && i < num; i++) {
- struct i2c_msg *pmsg = &msgs[i];
- bool last = (i == (num - 1));
-
- dev_dbg(i2c->dev,
- "Doing %s %d byte(s) to/from 0x%02x - %d of %d messages\n",
- pmsg->flags & I2C_M_RD ? "read" : "write",
- pmsg->len, pmsg->addr, i + 1, num);
- if (pmsg->flags & I2C_M_RD)
- ret = octeon_i2c_read(i2c, pmsg->addr, pmsg->buf,
- &pmsg->len, !i, last,
- pmsg->flags & I2C_M_RECV_LEN);
- else
- ret = octeon_i2c_write(i2c, pmsg->addr, pmsg->buf,
- pmsg->len, !i, last);
- }
- octeon_i2c_stop(i2c);
-out:
- return (ret != 0) ? ret : num;
-}
-
static u32 octeon_i2c_functionality(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
--
1.9.1