[PATCH] i2c: add Faraday FTIIC010 I2C controller support

[Po-Yu Chuang]

From: Po-Yu Chuang <ratbert@xxxxxxxxxxxxxxxx>

Support for Faraday FTIIC010 I2C controller. It is used on
Faraday A320, A369 and some other ARM SoC's.

Signed-off-by: Po-Yu Chuang <ratbert@xxxxxxxxxxxxxxxx>
---
 drivers/i2c/busses/Kconfig        |    7 +
 drivers/i2c/busses/Makefile       |    1 +
 drivers/i2c/busses/i2c-ftiic010.c |  434 +++++++++++++++++++++++++++++++++++++
 drivers/i2c/busses/i2c-ftiic010.h |  155 +++++++++++++
 4 files changed, 597 insertions(+), 0 deletions(-)
 create mode 100644 drivers/i2c/busses/i2c-ftiic010.c
 create mode 100644 drivers/i2c/busses/i2c-ftiic010.h

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 326652f..612c2b1 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -358,6 +358,13 @@ config I2C_DESIGNWARE
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-designware.
 
+config I2C_FTIIC010
+	tristate "Faraday FTIIC010 I2C controller"
+	depends on HAVE_CLK
+	help
+	  Support for Faraday FTIIC010 I2C controller. It is used on
+	  Faraday A320, A369 and some other ARM SoC's.
+
 config I2C_GPIO
 	tristate "GPIO-based bitbanging I2C"
 	depends on GENERIC_GPIO
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index e6cf294..c49570d 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_I2C_BLACKFIN_TWI)	+= i2c-bfin-twi.o
 obj-$(CONFIG_I2C_CPM)		+= i2c-cpm.o
 obj-$(CONFIG_I2C_DAVINCI)	+= i2c-davinci.o
 obj-$(CONFIG_I2C_DESIGNWARE)	+= i2c-designware.o
+obj-$(CONFIG_I2C_FTIIC010)	+= i2c-ftiic010.o
 obj-$(CONFIG_I2C_GPIO)		+= i2c-gpio.o
 obj-$(CONFIG_I2C_HIGHLANDER)	+= i2c-highlander.o
 obj-$(CONFIG_I2C_IBM_IIC)	+= i2c-ibm_iic.o
diff --git a/drivers/i2c/busses/i2c-ftiic010.c b/drivers/i2c/busses/i2c-ftiic010.c
new file mode 100644
index 0000000..ed86f06
--- /dev/null
+++ b/drivers/i2c/busses/i2c-ftiic010.c
@@ -0,0 +1,434 @@
+/*
+ * Faraday FTIIC010 I2C Controller
+ *
+ * (C) Copyright 2010-2011 Faraday Technology
+ * Po-Yu Chuang <ratbert@xxxxxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "i2c-ftiic010.h"
+
+#define SCL_SPEED	(100 * 1000)
+#define MAX_RETRY	1000
+
+#define GSR	5
+#define TSR	5
+
+struct ftiic010 {
+	struct resource *res;
+	void __iomem *base;
+	int irq;
+	struct clk *clk;
+	struct i2c_adapter adapter;
+};
+
+/******************************************************************************
+ * internal functions
+ *****************************************************************************/
+static void ftiic010_reset(struct ftiic010 *ftiic010)
+{
+	int cr = FTIIC010_CR_I2C_RST;
+
+	iowrite32(cr, ftiic010->base + FTIIC010_OFFSET_CR);
+
+	/* wait until reset bit cleared by hw */
+	while (ioread32(ftiic010->base + FTIIC010_OFFSET_CR) & FTIIC010_CR_I2C_RST)
+		;
+}
+
+static void ftiic010_set_clock_speed(struct ftiic010 *ftiic010, int hz)
+{
+	unsigned long pclk;
+	int cdr;
+
+	pclk = clk_get_rate(ftiic010->clk);
+
+	cdr = (pclk / hz - GSR) / 2 - 2;
+	cdr &= FTIIC010_CDR_MASK;
+
+	dev_dbg(&ftiic010->adapter.dev, "  [CDR] = %08x\n", cdr);
+	iowrite32(cdr, ftiic010->base + FTIIC010_OFFSET_CDR);
+}
+
+static void ftiic010_set_tgsr(struct ftiic010 *ftiic010, int tsr, int gsr)
+{
+	int tgsr;
+
+	tgsr = FTIIC010_TGSR_TSR(tsr);
+	tgsr |= FTIIC010_TGSR_GSR(gsr);
+
+	dev_dbg(&ftiic010->adapter.dev, "  [TGSR] = %08x\n", tgsr);
+	iowrite32(tgsr, ftiic010->base + FTIIC010_OFFSET_TGSR);
+}
+
+static void ftiic010_hw_init(struct ftiic010 *ftiic010)
+{
+	ftiic010_reset(ftiic010);
+	ftiic010_set_tgsr(ftiic010, TSR, GSR);
+	ftiic010_set_clock_speed(ftiic010, SCL_SPEED);
+}
+
+static inline void ftiic010_set_cr(struct ftiic010 *ftiic010, int start,
+		int stop, int nak)
+{
+	int cr;
+
+	cr = FTIIC010_CR_I2C_EN
+	   | FTIIC010_CR_SCL_EN
+	   | FTIIC010_CR_TB_EN
+	   | FTIIC010_CR_BERRI_EN
+	   | FTIIC010_CR_ALI_EN;
+
+	if (start)
+		cr |= FTIIC010_CR_START;
+
+	if (stop)
+		cr |= FTIIC010_CR_STOP;
+
+	if (nak)
+		cr |= FTIIC010_CR_NAK;
+
+	iowrite32(cr, ftiic010->base + FTIIC010_OFFSET_CR);
+}
+
+static int ftiic010_tx_byte(struct ftiic010 *ftiic010, __u8 data, int start,
+		int stop)
+{
+	struct i2c_adapter *adapter = &ftiic010->adapter;
+	int i;
+
+	iowrite32(data, ftiic010->base + FTIIC010_OFFSET_DR);
+	ftiic010_set_cr(ftiic010, start, stop, 0);
+
+	for (i = 0; i < MAX_RETRY; i++) {
+		unsigned int status;
+
+		status = ioread32(ftiic010->base + FTIIC010_OFFSET_SR);
+		if (status & FTIIC010_SR_DT)
+			return 0;
+
+		udelay(1);
+	}
+
+	dev_err(&adapter->dev, "Failed to transmit\n");
+	ftiic010_reset(ftiic010);
+	return -EIO;
+}
+
+static int ftiic010_rx_byte(struct ftiic010 *ftiic010, int stop, int nak)
+{
+	struct i2c_adapter *adapter = &ftiic010->adapter;
+	int i;
+
+	ftiic010_set_cr(ftiic010, 0, stop, nak);
+
+	for (i = 0; i < MAX_RETRY; i++) {
+		unsigned int status;
+
+		status = ioread32(ftiic010->base + FTIIC010_OFFSET_SR);
+		if (status & FTIIC010_SR_DR) {
+			return ioread32(ftiic010->base + FTIIC010_OFFSET_DR)
+				& FTIIC010_DR_MASK;
+		}
+
+		udelay(1);
+	}
+
+	dev_err(&adapter->dev, "Failed to receive\n");
+	ftiic010_reset(ftiic010);
+	return -EIO;
+}
+
+static int ftiic010_tx_msg(struct ftiic010 *ftiic010,
+		struct i2c_msg *msg, int last)
+{
+	__u8 data;
+	int ret;
+	int i;
+
+	data = (msg->addr & 0x7f) << 1;
+	ret = ftiic010_tx_byte(ftiic010, data, 1, 0);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < msg->len; i++) {
+		int stop = 0;
+
+		if (last && i + 1 == msg->len)
+			stop = 1;
+
+		ret = ftiic010_tx_byte(ftiic010, msg->buf[i], 0, stop);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int ftiic010_rx_msg(struct ftiic010 *ftiic010,
+		struct i2c_msg *msg, int last)
+{
+	__u8 data;
+	int ret;
+	int i;
+
+	data = (msg->addr & 0x7f) << 1 | 1;
+	ret = ftiic010_tx_byte(ftiic010, data, 1, 0);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < msg->len; i++) {
+		int nak = 0;
+
+		if (i + 1 == msg->len)
+			nak = 1;
+
+		ret = ftiic010_rx_byte(ftiic010, last, nak);
+		if (ret < 0)
+			return ret;
+
+		msg->buf[i] = ret;
+	}
+
+	return 0;
+}
+
+static int ftiic010_do_msg(struct ftiic010 *ftiic010,
+		struct i2c_msg *msg, int last)
+{
+	if (msg->flags & I2C_M_RD)
+		return ftiic010_rx_msg(ftiic010, msg, last);
+	else
+		return ftiic010_tx_msg(ftiic010, msg, last);
+}
+
+/******************************************************************************
+ * interrupt handler
+ *****************************************************************************/
+static irqreturn_t ftiic010_interrupt(int irq, void *dev_id)
+{
+	struct ftiic010 *ftiic010 = dev_id;
+	struct i2c_adapter *adapter = &ftiic010->adapter;
+	int sr;
+
+	sr = ioread32(ftiic010->base + FTIIC010_OFFSET_SR);
+
+	if (sr & FTIIC010_SR_BERR) {
+		dev_err(&adapter->dev, "NAK!\n");
+		ftiic010_reset(ftiic010);
+	}
+
+	if (sr & FTIIC010_SR_AL) {
+		dev_err(&adapter->dev, "arbitration lost!\n");
+		ftiic010_reset(ftiic010);
+	}
+
+	return IRQ_HANDLED;
+}
+
+/******************************************************************************
+ * struct i2c_algorithm functions
+ *****************************************************************************/
+static int ftiic010_master_xfer(struct i2c_adapter *adapter,
+		struct i2c_msg *msgs, int num)
+{
+	struct ftiic010 *ftiic010 = i2c_get_adapdata(adapter);
+	int i;
+
+	for (i = 0; i < num; i++) {
+		int last = 0;
+		int ret;
+
+		if (i == num - 1)
+			last = 1;
+
+		ret = ftiic010_do_msg(ftiic010, &msgs[i], last);
+		if (ret)
+			return ret;
+	}
+
+	return num;
+}
+
+static u32 ftiic010_functionality(struct i2c_adapter *adapter)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static struct i2c_algorithm ftiic010_algorithm = {
+	.master_xfer	= ftiic010_master_xfer,
+	.functionality	= ftiic010_functionality,
+};
+
+/******************************************************************************
+ * struct platform_driver functions
+ *****************************************************************************/
+static int ftiic010_probe(struct platform_device *pdev)
+{
+	struct ftiic010 *ftiic010;
+	struct resource *res;
+	struct clk *clk;
+	int irq;
+	int ret;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENXIO;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	ftiic010 = kzalloc(sizeof(*ftiic010), GFP_KERNEL);
+	if (!ftiic010) {
+		dev_err(&pdev->dev, "Could not allocate private data\n");
+		ret = -ENOMEM;
+		goto err_alloc;
+	}
+
+	ftiic010->res = request_mem_region(res->start, resource_size(res),
+					   dev_name(&pdev->dev));
+	if (!ftiic010->res) {
+		dev_err(&pdev->dev, "Could not reserve memory region\n");
+		ret = -ENOMEM;
+		goto err_req_mem;
+	}
+
+	ftiic010->base = ioremap(res->start, resource_size(res));
+	if (!ftiic010->base) {
+		dev_err(&pdev->dev, "Failed to ioremap\n");
+		ret = -ENOMEM;
+		goto err_ioremap;
+	}
+
+	ret = request_irq(irq, ftiic010_interrupt, IRQF_SHARED, pdev->name,
+			  ftiic010);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request irq %d\n", irq);
+		goto err_req_irq;
+	}
+
+	ftiic010->irq = irq;
+
+	clk = clk_get(NULL, "pclk");
+	if (!clk) {
+		dev_err(&pdev->dev, "Failed to get pclk\n");
+		goto err_clk;
+	}
+
+	clk_enable(clk);
+	ftiic010->clk = clk;
+
+	/*
+	 * initialize i2c adapter
+	 */
+	ftiic010->adapter.owner		= THIS_MODULE;
+	ftiic010->adapter.algo		= &ftiic010_algorithm;
+	ftiic010->adapter.timeout	= 1;
+	ftiic010->adapter.dev.parent	= &pdev->dev;
+
+	/*
+	 * If "dev->id" is negative we consider it as zero.
+	 * The reason to do so is to avoid sysfs names that only make
+	 * sense when there are multiple adapters.
+	 */
+	ftiic010->adapter.nr		= pdev->id != -1 ? pdev->id : 0;
+	strcpy(ftiic010->adapter.name, "ftiic010 adapter");
+
+	i2c_set_adapdata(&ftiic010->adapter, ftiic010);
+
+	ftiic010_hw_init(ftiic010);
+
+	ret = i2c_add_numbered_adapter(&ftiic010->adapter);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to add i2c adapter\n");
+		goto err_add_adapter;
+	}
+
+	platform_set_drvdata(pdev, ftiic010);
+
+	dev_info(&pdev->dev, "irq %d, mapped at %p\n", irq, ftiic010->base);
+
+	return 0;
+
+err_add_adapter:
+	clk_disable(clk);
+	clk_put(clk);
+err_clk:
+	free_irq(ftiic010->irq, ftiic010);
+err_req_irq:
+	iounmap(ftiic010->base);
+err_ioremap:
+	release_resource(ftiic010->res);
+err_req_mem:
+	kfree(ftiic010);
+err_alloc:
+	return ret;
+};
+
+static int __devexit ftiic010_remove(struct platform_device *pdev)
+{
+	struct ftiic010 *ftiic010 = platform_get_drvdata(pdev);
+
+	platform_set_drvdata(pdev, NULL);
+	i2c_del_adapter(&ftiic010->adapter);
+	clk_disable(ftiic010->clk);
+	clk_put(ftiic010->clk);
+	free_irq(ftiic010->irq, ftiic010);
+	iounmap(ftiic010->base);
+	release_resource(ftiic010->res);
+	kfree(ftiic010);
+	return 0;
+};
+
+
+static struct platform_driver ftiic010_driver = {
+	.probe		= ftiic010_probe,
+	.remove		= __devexit_p(ftiic010_remove),
+	.driver		= {
+		.name	= "ftiic010",
+		.owner	= THIS_MODULE,
+	},
+};
+
+/******************************************************************************
+ * initialization / finalization
+ *****************************************************************************/
+static int __init ftiic010_init(void)
+{
+	return platform_driver_register(&ftiic010_driver);
+}
+
+static void __exit ftiic010_exit(void)
+{
+	platform_driver_unregister(&ftiic010_driver);
+}
+
+module_init(ftiic010_init);
+module_exit(ftiic010_exit);
+
+MODULE_AUTHOR("Po-Yu Chuang <ratbert@xxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("FTIIC010 I2C bus adapter");
+MODULE_LICENSE("GPL");
diff --git a/drivers/i2c/busses/i2c-ftiic010.h b/drivers/i2c/busses/i2c-ftiic010.h
new file mode 100644
index 0000000..c1f4752
--- /dev/null
+++ b/drivers/i2c/busses/i2c-ftiic010.h
@@ -0,0 +1,155 @@
+/*
+ * Faraday FTIIC010 I2C Controller
+ *
+ * (C) Copyright 2010-2011 Faraday Technology
+ * Po-Yu Chuang <ratbert@xxxxxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef __FTIIC010_H
+#define __FTIIC010_H
+
+#define FTIIC010_OFFSET_CR	0x00
+#define FTIIC010_OFFSET_SR	0x04
+#define FTIIC010_OFFSET_CDR	0x08
+#define FTIIC010_OFFSET_DR	0x0c
+#define FTIIC010_OFFSET_SAR	0x10
+#define FTIIC010_OFFSET_TGSR	0x14
+#define FTIIC010_OFFSET_BMR	0x18
+#define FTIIC010_OFFSET_SMCR	0x1c
+#define FTIIC010_OFFSET_MAXTR	0x20
+#define FTIIC010_OFFSET_MINTR	0x24
+#define FTIIC010_OFFSET_METR	0x28
+#define FTIIC010_OFFSET_SETR	0x2c
+#define FTIIC010_OFFSET_REV	0x30
+#define FTIIC010_OFFSET_FEAT	0x34
+
+/*
+ * Control Register
+ */
+#define FTIIC010_CR_I2C_RST	(1 << 0)
+#define FTIIC010_CR_I2C_EN	(1 << 1)
+#define FTIIC010_CR_SCL_EN	(1 << 2)
+#define FTIIC010_CR_GC_EN	(1 << 3)
+#define FTIIC010_CR_START	(1 << 4)
+#define FTIIC010_CR_STOP	(1 << 5)
+#define FTIIC010_CR_NAK		(1 << 6)
+#define FTIIC010_CR_TB_EN	(1 << 7)
+#define FTIIC010_CR_DTI_EN	(1 << 8)
+#define FTIIC010_CR_DRI_EN	(1 << 9)
+#define FTIIC010_CR_BERRI_EN	(1 << 10)
+#define FTIIC010_CR_STOPI_EN	(1 << 11)
+#define FTIIC010_CR_SAMI_EN	(1 << 12)
+#define FTIIC010_CR_ALI_EN	(1 << 13)	/* arbitration lost */
+#define FTIIC010_CR_STARTI_EN	(1 << 14)
+#define FTIIC010_CR_SCL_LOW	(1 << 15)
+#define FTIIC010_CR_SDA_LOW	(1 << 16)
+#define FTIIC010_CR_TESTMODE	(1 << 17)
+
+/*
+ * Status Register
+ */
+#define FTIIC010_SR_RW		(1 << 0)
+#define FTIIC010_SR_ACK		(1 << 1)
+#define FTIIC010_SR_I2CBUSY	(1 << 2)
+#define FTIIC010_SR_BUSBUSY	(1 << 3)
+#define FTIIC010_SR_DT		(1 << 4)
+#define FTIIC010_SR_DR		(1 << 5)
+#define FTIIC010_SR_BERR	(1 << 6)
+#define FTIIC010_SR_STOP	(1 << 7)
+#define FTIIC010_SR_SAM		(1 << 8)
+#define FTIIC010_SR_GC		(1 << 9)
+#define FTIIC010_SR_AL		(1 << 10)
+#define FTIIC010_SR_START	(1 << 11)
+#define FTIIC010_SR_SEXT	(1 << 12)
+#define FTIIC010_SR_MEXT	(1 << 13)
+#define FTIIC010_SR_MINTIMEOUT	(1 << 14)
+#define FTIIC010_SR_MAXTIMEOUT	(1 << 15)
+#define FTIIC010_SR_ALERT	(1 << 16)
+#define FTIIC010_SR_SUSPEND	(1 << 17)
+#define FTIIC010_SR_RESUME	(1 << 18)
+#define FTIIC010_SR_ARA		(1 << 19)
+#define FTIIC010_SR_DDA		(1 << 20)
+#define FTIIC010_SR_SAL		(1 << 21)
+
+/*
+ * Clock Division Register
+ */
+#define FTIIC010_CDR_MASK	0x3ffff
+
+/*
+ * Data Register
+ */
+#define FTIIC010_DR_MASK	0xff
+
+/*
+ * Slave Address Register
+ */
+#define FTIIC010_SAR_MASK	0x3ff
+#define FTIIC010_SAR_EN10	(1 << 31)
+
+/*
+ * Set/Hold Time Glitch Suppression Setting Register
+ */
+#define FTIIC010_TGSR_TSR(x)	((x) & 0x3ff)	/* should not be zero */
+#define FTIIC010_TGSR_GSR(x)	(((x) & 0x7) << 10)
+
+/*
+ * Bus Monitor Register
+ */
+#define FTIIC010_BMR_SDA_IN	(1 << 0)
+#define FTIIC010_BMR_SCL_IN	(1 << 1)
+
+/*
+ * SM Control Register
+ */
+#define FTIIC010_SMCR_SEXT_EN	(1 << 0)
+#define FTIIC010_SMCR_MEXT_EN	(1 << 1)
+#define FTIIC010_SMCR_TOUT_EN	(1 << 2)
+#define FTIIC010_SMCR_ALERT_EN	(1 << 3)
+#define FTIIC010_SMCR_SUS_EN	(1 << 4)
+#define FTIIC010_SMCR_RSM_EN	(1 << 5)
+#define FTIIC010_SMCR_SAL_EN	(1 << 8)
+#define FTIIC010_SMCR_ALERT_LOW	(1 << 9)
+#define FTIIC010_SMCR_SUS_LOW	(1 << 10)
+#define FTIIC010_SMCR_SUSOUT_EN	(1 << 11)
+
+/*
+ * SM Maximum Timeout Register
+ */
+#define FTIIC010_MAXTR_MASK	0x3fffff
+
+/*
+ * SM Minimum Timeout Register
+ */
+#define FTIIC010_MINTR_MASK	0x3fffff
+
+/*
+ * SM Master Extend Time Register
+ */
+#define FTIIC010_METR_MASK	0xfffff
+
+/*
+ * SM Slave Extend Time Register
+ */
+#define FTIIC010_SETR_MASK	0x1fffff
+
+/*
+ * Feature Register
+ */
+#define FTIIC010_FEAT_SMBUS	(1 << 0)
+
+#endif /* __FTIIC010_H */
-- 
1.6.3.3

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