[PATCH 5/7] i2c: Add device tree support to i2c-pnx.c

From: Roland Stigge
Date: Mon Apr 02 2012 - 08:59:29 EST

This patch adds device tree support to the pnx-i2c driver by using platform
resources for memory region and irq and removing dependency on mach includes.

The following platforms are affected:

* PNX
* LPC31xx (WIP)
* LPC32xx

The patch is based on a patch by Jon Smirl, working on lpc31xx integration

Signed-off-by: Roland Stigge <stigge@xxxxxxxxx>

---

Applies to v3.4-rc1

Updates:
* Introducing slave-addr for I2C controller (this convention already exists in
the kernel)
* Bugfix: of_i2c_register_devices() was missing

Documentation/devicetree/bindings/i2c/pnx.txt | 36 +++++
drivers/i2c/busses/i2c-pnx.c | 160 +++++++++++++++++++-------
include/linux/i2c-pnx.h | 10 -
3 files changed, 158 insertions(+), 48 deletions(-)

--- /dev/null
+++ linux-2.6/Documentation/devicetree/bindings/i2c/pnx.txt
@@ -0,0 +1,36 @@
+* NXP PNX I2C Controller
+
+Required properties:
+
+ - reg: Offset and length of the register set for the device
+ - compatible: should be "nxp,pnx-i2c"
+ - interrupts: <a b> where a is the interrupt number and b is a
+ field that represents an encoding of the sense and level
+ information for the interrupt
+ - interrupt-parent: the phandle for the interrupt controller that
+ services interrupts for this device.
+
+Optional properties:
+
+ - clock-frequency: desired I2C bus clock frequency in Hz, Default: 100000 Hz
+ - pnx,timeout: I2C bus timeout in milliseconds, Default: 10 ms
+ - slave-addr: Address used by the controller, Hardware default: 110
+
+Examples:
+
+ i2c1: i2c@400A0000 {
+ compatible = "nxp,pnx-i2c";
+ reg = <0x400A0000 0x100>;
+ interrupt-parent = <&mic>;
+ interrupts = <51 0>;
+ };
+
+ i2c2: i2c@400A8000 {
+ compatible = "nxp,pnx-i2c";
+ reg = <0x400A8000 0x100>;
+ interrupt-parent = <&mic>;
+ interrupts = <50 0>;
+ clock-frequency = <0x186a0>;
+ pnx,timeout = <0x64>;
+ slave-addr = <0x11>;
+ };
--- linux-2.6.orig/drivers/i2c/busses/i2c-pnx.c
+++ linux-2.6/drivers/i2c/busses/i2c-pnx.c
@@ -23,16 +23,61 @@
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/slab.h>
+#include <linux/of_i2c.h>

-#include <mach/hardware.h>
-#include <mach/i2c.h>
+#define I2C_PNX_TIMEOUT_DEFAULT 10 /* msec */
+#define I2C_PNX_SPEED_KHZ_DEFAULT 100
+#define I2C_PNX_REGION_SIZE 0x100
+
+enum {
+ mstatus_tdi = 0x00000001,
+ mstatus_afi = 0x00000002,
+ mstatus_nai = 0x00000004,
+ mstatus_drmi = 0x00000008,
+ mstatus_active = 0x00000020,
+ mstatus_scl = 0x00000040,
+ mstatus_sda = 0x00000080,
+ mstatus_rff = 0x00000100,
+ mstatus_rfe = 0x00000200,
+ mstatus_tff = 0x00000400,
+ mstatus_tfe = 0x00000800,
+};
+
+enum {
+ mcntrl_tdie = 0x00000001,
+ mcntrl_afie = 0x00000002,
+ mcntrl_naie = 0x00000004,
+ mcntrl_drmie = 0x00000008,
+ mcntrl_daie = 0x00000020,
+ mcntrl_rffie = 0x00000040,
+ mcntrl_tffie = 0x00000080,
+ mcntrl_reset = 0x00000100,
+ mcntrl_cdbmode = 0x00000400,
+};

-#define I2C_PNX_TIMEOUT 10 /* msec */
-#define I2C_PNX_SPEED_KHZ 100
-#define I2C_PNX_REGION_SIZE 0x100
+enum {
+ rw_bit = 1 << 0,
+ start_bit = 1 << 8,
+ stop_bit = 1 << 9,
+};
+
+#define I2C_REG_RX(a) ((a)->ioaddr) /* Rx FIFO reg (RO) */
+#define I2C_REG_TX(a) ((a)->ioaddr) /* Tx FIFO reg (WO) */
+#define I2C_REG_STS(a) ((a)->ioaddr + 0x04) /* Status reg (RO) */
+#define I2C_REG_CTL(a) ((a)->ioaddr + 0x08) /* Ctl reg */
+#define I2C_REG_CKL(a) ((a)->ioaddr + 0x0c) /* Clock divider low */
+#define I2C_REG_CKH(a) ((a)->ioaddr + 0x10) /* Clock divider high */
+#define I2C_REG_ADR(a) ((a)->ioaddr + 0x14) /* I2C address */
+#define I2C_REG_RFL(a) ((a)->ioaddr + 0x18) /* Rx FIFO level (RO) */
+#define I2C_REG_TFL(a) ((a)->ioaddr + 0x1c) /* Tx FIFO level (RO) */
+#define I2C_REG_RXB(a) ((a)->ioaddr + 0x20) /* Num of bytes Rx-ed (RO) */
+#define I2C_REG_TXB(a) ((a)->ioaddr + 0x24) /* Num of bytes Tx-ed (RO) */
+#define I2C_REG_TXS(a) ((a)->ioaddr + 0x28) /* Tx slave FIFO (RO) */
+#define I2C_REG_STFL(a) ((a)->ioaddr + 0x2c) /* Tx slave FIFO level (RO) */

-static inline int wait_timeout(long timeout, struct i2c_pnx_algo_data *data)
+static inline int wait_timeout(struct i2c_pnx_algo_data *data)
{
+ long timeout = data->timeout;
while (timeout > 0 &&
(ioread32(I2C_REG_STS(data)) & mstatus_active)) {
mdelay(1);
@@ -41,8 +86,9 @@ static inline int wait_timeout(long time
return (timeout <= 0);
}

-static inline int wait_reset(long timeout, struct i2c_pnx_algo_data *data)
+static inline int wait_reset(struct i2c_pnx_algo_data *data)
{
+ long timeout = data->timeout;
while (timeout > 0 &&
(ioread32(I2C_REG_CTL(data)) & mcntrl_reset)) {
mdelay(1);
@@ -54,7 +100,7 @@ static inline int wait_reset(long timeou
static inline void i2c_pnx_arm_timer(struct i2c_pnx_algo_data *alg_data)
{
struct timer_list *timer = &alg_data->mif.timer;
- unsigned long expires = msecs_to_jiffies(I2C_PNX_TIMEOUT);
+ unsigned long expires = msecs_to_jiffies(alg_data->timeout);

if (expires <= 1)
expires = 2;
@@ -92,7 +138,7 @@ static int i2c_pnx_start(unsigned char s
}

/* First, make sure bus is idle */
- if (wait_timeout(I2C_PNX_TIMEOUT, alg_data)) {
+ if (wait_timeout(alg_data)) {
/* Somebody else is monopolizing the bus */
dev_err(&alg_data->adapter.dev,
"%s: Bus busy. Slave addr = %02x, cntrl = %x, stat = %x\n",
@@ -185,7 +231,7 @@ static int i2c_pnx_master_xmit(struct i2
if (alg_data->mif.len == 0) {
if (alg_data->last) {
/* Wait until the STOP is seen. */
- if (wait_timeout(I2C_PNX_TIMEOUT, alg_data))
+ if (wait_timeout(alg_data))
dev_err(&alg_data->adapter.dev,
"The bus is still active after timeout\n");
}
@@ -283,7 +329,7 @@ static int i2c_pnx_master_rcv(struct i2c
if (alg_data->mif.len == 0) {
if (alg_data->last)
/* Wait until the STOP is seen. */
- if (wait_timeout(I2C_PNX_TIMEOUT, alg_data))
+ if (wait_timeout(alg_data))
dev_err(&alg_data->adapter.dev,
"The bus is still active after timeout\n");

@@ -399,7 +445,7 @@ static void i2c_pnx_timeout(unsigned lon

ctl |= mcntrl_reset;
iowrite32(ctl, I2C_REG_CTL(alg_data));
- wait_reset(I2C_PNX_TIMEOUT, alg_data);
+ wait_reset(alg_data);
alg_data->mif.ret = -EIO;
complete(&alg_data->mif.complete);
}
@@ -414,18 +460,18 @@ static inline void bus_reset_if_active(s
alg_data->adapter.name);
iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
I2C_REG_CTL(alg_data));
- wait_reset(I2C_PNX_TIMEOUT, alg_data);
+ wait_reset(alg_data);
} else if (!(stat & mstatus_rfe) || !(stat & mstatus_tfe)) {
/* If there is data in the fifo's after transfer,
* flush fifo's by reset.
*/
iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
I2C_REG_CTL(alg_data));
- wait_reset(I2C_PNX_TIMEOUT, alg_data);
+ wait_reset(alg_data);
} else if (stat & mstatus_nai) {
iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
I2C_REG_CTL(alg_data));
- wait_reset(I2C_PNX_TIMEOUT, alg_data);
+ wait_reset(alg_data);
}
}

@@ -569,14 +615,9 @@ static int __devinit i2c_pnx_probe(struc
int ret = 0;
struct i2c_pnx_algo_data *alg_data;
unsigned long freq;
- struct i2c_pnx_data *i2c_pnx = pdev->dev.platform_data;
-
- if (!i2c_pnx || !i2c_pnx->name) {
- dev_err(&pdev->dev, "%s: no platform data supplied\n",
- __func__);
- ret = -EINVAL;
- goto out;
- }
+ struct resource *res;
+ u32 speed = I2C_PNX_SPEED_KHZ_DEFAULT * 1000;
+ u32 slave_addr = ~0;

alg_data = kzalloc(sizeof(*alg_data), GFP_KERNEL);
if (!alg_data) {
@@ -586,14 +627,22 @@ static int __devinit i2c_pnx_probe(struc

platform_set_drvdata(pdev, alg_data);

- strlcpy(alg_data->adapter.name, i2c_pnx->name,
- sizeof(alg_data->adapter.name));
alg_data->adapter.dev.parent = &pdev->dev;
alg_data->adapter.algo = &pnx_algorithm;
alg_data->adapter.algo_data = alg_data;
alg_data->adapter.nr = pdev->id;
- alg_data->i2c_pnx = i2c_pnx;
-
+ alg_data->timeout = I2C_PNX_TIMEOUT_DEFAULT;
+#ifdef CONFIG_OF
+ alg_data->adapter.dev.of_node = of_node_get(pdev->dev.of_node);
+ if (pdev->dev.of_node) {
+ of_property_read_u32(pdev->dev.of_node, "pnx,timeout",
+ &alg_data->timeout);
+ of_property_read_u32(pdev->dev.of_node, "clock-frequency",
+ &speed);
+ of_property_read_u32(pdev->dev.of_node, "slave-addr",
+ &slave_addr);
+ }
+#endif
alg_data->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(alg_data->clk)) {
ret = PTR_ERR(alg_data->clk);
@@ -604,17 +653,27 @@ static int __devinit i2c_pnx_probe(struc
alg_data->mif.timer.function = i2c_pnx_timeout;
alg_data->mif.timer.data = (unsigned long)alg_data;

+ snprintf(alg_data->adapter.name, sizeof(alg_data->adapter.name),
+ "%s", pdev->name);
+
/* Register I/O resource */
- if (!request_mem_region(i2c_pnx->base, I2C_PNX_REGION_SIZE,
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "Unable to get mem resource.\n");
+ ret = -EBUSY;
+ goto out_clkget;
+ }
+ if (!request_mem_region(res->start, I2C_PNX_REGION_SIZE,
pdev->name)) {
dev_err(&pdev->dev,
"I/O region 0x%08x for I2C already in use.\n",
- i2c_pnx->base);
- ret = -ENODEV;
+ res->start);
+ ret = -ENOMEM;
goto out_clkget;
}

- alg_data->ioaddr = ioremap(i2c_pnx->base, I2C_PNX_REGION_SIZE);
+ alg_data->base = res->start;
+ alg_data->ioaddr = ioremap(res->start, I2C_PNX_REGION_SIZE);
if (!alg_data->ioaddr) {
dev_err(&pdev->dev, "Couldn't ioremap I2C I/O region\n");
ret = -ENOMEM;
@@ -625,6 +684,9 @@ static int __devinit i2c_pnx_probe(struc
if (ret)
goto out_unmap;

+ if (slave_addr != ~0)
+ iowrite32(slave_addr, I2C_REG_ADR(alg_data));
+
freq = clk_get_rate(alg_data->clk);

/*
@@ -638,20 +700,25 @@ static int __devinit i2c_pnx_probe(struc
* the deglitching filter length.
*/

- tmp = ((freq / 1000) / I2C_PNX_SPEED_KHZ) / 2 - 2;
+ tmp = (freq / speed) / 2 - 2;
if (tmp > 0x3FF)
tmp = 0x3FF;
iowrite32(tmp, I2C_REG_CKH(alg_data));
iowrite32(tmp, I2C_REG_CKL(alg_data));

iowrite32(mcntrl_reset, I2C_REG_CTL(alg_data));
- if (wait_reset(I2C_PNX_TIMEOUT, alg_data)) {
+ if (wait_reset(alg_data)) {
ret = -ENODEV;
goto out_clock;
}
init_completion(&alg_data->mif.complete);

- ret = request_irq(i2c_pnx->irq, i2c_pnx_interrupt,
+ alg_data->irq = platform_get_irq(pdev, 0);
+ if (alg_data->irq < 0) {
+ dev_err(&pdev->dev, "Failed to get IRQ from platform resource\n");
+ goto out_irq;
+ }
+ ret = request_irq(alg_data->irq, i2c_pnx_interrupt,
0, pdev->name, alg_data);
if (ret)
goto out_clock;
@@ -663,39 +730,39 @@ static int __devinit i2c_pnx_probe(struc
goto out_irq;
}

+ of_i2c_register_devices(&alg_data->adapter);
+
dev_dbg(&pdev->dev, "%s: Master at %#8x, irq %d.\n",
- alg_data->adapter.name, i2c_pnx->base, i2c_pnx->irq);
+ alg_data->adapter.name, res->start, alg_data->irq);

return 0;

out_irq:
- free_irq(i2c_pnx->irq, alg_data);
+ free_irq(alg_data->irq, alg_data);
out_clock:
clk_disable(alg_data->clk);
out_unmap:
iounmap(alg_data->ioaddr);
out_release:
- release_mem_region(i2c_pnx->base, I2C_PNX_REGION_SIZE);
+ release_mem_region(res->start, I2C_PNX_REGION_SIZE);
out_clkget:
clk_put(alg_data->clk);
out_drvdata:
kfree(alg_data);
err_kzalloc:
platform_set_drvdata(pdev, NULL);
-out:
return ret;
}

static int __devexit i2c_pnx_remove(struct platform_device *pdev)
{
struct i2c_pnx_algo_data *alg_data = platform_get_drvdata(pdev);
- struct i2c_pnx_data *i2c_pnx = alg_data->i2c_pnx;

- free_irq(i2c_pnx->irq, alg_data);
+ free_irq(alg_data->irq, alg_data);
i2c_del_adapter(&alg_data->adapter);
clk_disable(alg_data->clk);
iounmap(alg_data->ioaddr);
- release_mem_region(i2c_pnx->base, I2C_PNX_REGION_SIZE);
+ release_mem_region(alg_data->base, I2C_PNX_REGION_SIZE);
clk_put(alg_data->clk);
kfree(alg_data);
platform_set_drvdata(pdev, NULL);
@@ -703,10 +770,21 @@ static int __devexit i2c_pnx_remove(stru
return 0;
}

+#ifdef CONFIG_OF
+static const struct of_device_id i2c_pnx_of_match[] = {
+ { .compatible = "nxp,pnx-i2c" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, i2c_pnx_of_match);
+#endif
+
static struct platform_driver i2c_pnx_driver = {
.driver = {
.name = "pnx-i2c",
.owner = THIS_MODULE,
+#ifdef CONFIG_OF
+ .of_match_table = i2c_pnx_of_match,
+#endif
},
.probe = i2c_pnx_probe,
.remove = __devexit_p(i2c_pnx_remove),
--- linux-2.6.orig/include/linux/i2c-pnx.h
+++ linux-2.6/include/linux/i2c-pnx.h
@@ -29,14 +29,10 @@ struct i2c_pnx_algo_data {
struct i2c_pnx_mif mif;
int last;
struct clk *clk;
- struct i2c_pnx_data *i2c_pnx;
struct i2c_adapter adapter;
-};
-
-struct i2c_pnx_data {
- const char *name;
- u32 base;
- int irq;
+ phys_addr_t base;
+ int irq;
+ u32 timeout;
};

#endif /* __I2C_PNX_H__ */
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