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Commit a092de11 authored by Roland Stigge's avatar Roland Stigge Committed by Wolfram Sang
Browse files

i2c: pnx: add device tree support 



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: default avatarRoland Stigge <stigge@antcom.de>
Signed-off-by: default avatarWolfram Sang <w.sang@pengutronix.de>
parent 973c5ed4

Documentation/devicetree/bindings/i2c/pnx.txt

0 → 100644
+36 −0
Original line number Diff line number Diff line 
* NXP PNX I2C Controller



Required properties:



 - reg: Offset and length of the register set for the device

 - compatible: should be "nxp,pnx-i2c"

 - interrupts: configure one interrupt line

 - #address-cells: always 1 (for i2c addresses)

 - #size-cells: always 0

 - 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



Examples:



	i2c1: i2c@400a0000 {

		compatible = "nxp,pnx-i2c";

		reg = <0x400a0000 0x100>;

		interrupt-parent = <&mic>;

		interrupts = <51 0>;

		#address-cells = <1>;

		#size-cells = <0>;

	};



	i2c2: i2c@400a8000 {

		compatible = "nxp,pnx-i2c";

		reg = <0x400a8000 0x100>;

		interrupt-parent = <&mic>;

		interrupts = <50 0>;

		#address-cells = <1>;

		#size-cells = <0>;

		clock-frequency = <100000>;

	};

drivers/i2c/busses/i2c-pnx.c

+47 −16
Original line number Diff line number Diff line
@@ -23,9 +23,10 @@ 
#include <linux/err.h>

#include <linux/clk.h>

#include <linux/slab.h>

#include <linux/of_i2c.h>



#define I2C_PNX_TIMEOUT		10 /* msec */

#define I2C_PNX_SPEED_KHZ	100

#define I2C_PNX_TIMEOUT_DEFAULT		10 /* msec */

#define I2C_PNX_SPEED_KHZ_DEFAULT	100

#define I2C_PNX_REGION_SIZE		0x100



enum {
@@ -74,8 +75,9 @@ enum { 
#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);
@@ -84,8 +86,9 @@ static inline int wait_timeout(long timeout, struct i2c_pnx_algo_data *data) 
	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);
@@ -97,7 +100,7 @@ static inline int wait_reset(long timeout, struct i2c_pnx_algo_data *data) 
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;
@@ -135,7 +138,7 @@ static int i2c_pnx_start(unsigned char slave_addr, 
	}



	/* 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",
@@ -228,7 +231,7 @@ static int i2c_pnx_master_xmit(struct i2c_pnx_algo_data *alg_data) 
		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");

			}
@@ -326,7 +329,7 @@ static int i2c_pnx_master_rcv(struct i2c_pnx_algo_data *alg_data) 
		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");
@@ -442,7 +445,7 @@ static void i2c_pnx_timeout(unsigned long data) 


	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);

}
@@ -457,18 +460,18 @@ static inline void bus_reset_if_active(struct i2c_pnx_algo_data *alg_data) 
			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);

	}

}
@@ -612,6 +615,7 @@ static int __devinit i2c_pnx_probe(struct platform_device *pdev) 
	struct i2c_pnx_algo_data *alg_data;

	unsigned long freq;

	struct resource *res;

	u32 speed = I2C_PNX_SPEED_KHZ_DEFAULT * 1000;



	alg_data = kzalloc(sizeof(*alg_data), GFP_KERNEL);

	if (!alg_data) {
@@ -626,6 +630,22 @@ static int __devinit i2c_pnx_probe(struct platform_device *pdev) 
	alg_data->adapter.algo_data = alg_data;

	alg_data->adapter.nr = pdev->id;



	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, "clock-frequency",

				     &speed);

		/*

		 * At this point, it is planned to add an OF timeout property.

		 * As soon as there is a consensus about how to call and handle

		 * this, sth. like the following can be put here:

		 *

		 * of_property_read_u32(pdev->dev.of_node, "timeout",

		 *                      &alg_data->timeout);

		 */

	}

#endif

	alg_data->clk = clk_get(&pdev->dev, NULL);

	if (IS_ERR(alg_data->clk)) {

		ret = PTR_ERR(alg_data->clk);
@@ -651,7 +671,7 @@ static int __devinit i2c_pnx_probe(struct platform_device *pdev) 
		dev_err(&pdev->dev,

		       "I/O region 0x%08x for I2C already in use.\n",

		       res->start);

		ret = -ENODEV;

		ret = -ENOMEM;

		goto out_clkget;

	}
@@ -680,14 +700,14 @@ static int __devinit i2c_pnx_probe(struct platform_device *pdev) 
	 * 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;

	}
@@ -710,6 +730,8 @@ static int __devinit i2c_pnx_probe(struct platform_device *pdev) 
		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, res->start, alg_data->irq);
@@ -748,10 +770,19 @@ static int __devexit i2c_pnx_remove(struct platform_device *pdev) 
	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,

		.of_match_table = of_match_ptr(i2c_pnx_of_match),

	},

	.probe = i2c_pnx_probe,

	.remove = __devexit_p(i2c_pnx_remove),

include/linux/i2c-pnx.h

+1 −0
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ struct i2c_pnx_algo_data { 
	struct i2c_adapter	adapter;

	phys_addr_t		base;

	int			irq;

	u32			timeout;

};



#endif /* __I2C_PNX_H__ */