arch/arm/plat-omap/i2c.c - linux - Git at Google

 /*
  * linux/arch/arm/plat-omap/i2c.c
  *
  * Helper module for board specific I2C bus registration
  *
  * Copyright (C) 2007 Nokia Corporation.
  *
  * Contact: Jarkko Nikula <jhnikula@gmail.com>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * version 2 as published by the Free Software Foundation.
  *
  * 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., 51 Franklin St, Fifth Floor, Boston, MA
  * 02110-1301 USA
  *
  */

 #include <linux/kernel.h>
 #include <linux/platform_device.h>
 #include <linux/i2c.h>
 #include <linux/i2c-omap.h>
 #include <linux/slab.h>
 #include <linux/err.h>
 #include <linux/clk.h>

 #include <mach/irqs.h>
 #include <plat/i2c.h>
 #include <plat/omap-pm.h>
 #include <plat/omap_device.h>

 #define OMAP_I2C_SIZE		0x3f
 #define OMAP1_I2C_BASE		0xfffb3800
 #define OMAP1_INT_I2C		(32 + 4)

 static const char name[] = "omap_i2c";

 #define I2C_RESOURCE_BUILDER(base, irq)			\
 	{						\
 		.start	= (base),			\
 		.end	= (base) + OMAP_I2C_SIZE,	\
 		.flags	= IORESOURCE_MEM,		\
 	},						\
 	{						\
 		.start	= (irq),			\
 		.flags	= IORESOURCE_IRQ,		\
 	},

 static struct resource i2c_resources[][2] = {
 	{ I2C_RESOURCE_BUILDER(0, 0) },
 };

 #define I2C_DEV_BUILDER(bus_id, res, data)		\
 	{						\
 		.id	= (bus_id),			\
 		.name	= name,				\
 		.num_resources	= ARRAY_SIZE(res),	\
 		.resource	= (res),		\
 		.dev		= {			\
 			.platform_data	= (data),	\
 		},					\
 	}

 #define MAX_OMAP_I2C_HWMOD_NAME_LEN	16
 #define OMAP_I2C_MAX_CONTROLLERS 4
 static struct omap_i2c_bus_platform_data i2c_pdata[OMAP_I2C_MAX_CONTROLLERS];
 static struct platform_device omap_i2c_devices[] = {
 	I2C_DEV_BUILDER(1, i2c_resources[0], &i2c_pdata[0]),
 };

 #define OMAP_I2C_CMDLINE_SETUP	(BIT(31))

 static int __init omap_i2c_nr_ports(void)
 {
 	int ports = 0;

 	if (cpu_class_is_omap1())
 		ports = 1;
 	else if (cpu_is_omap24xx())
 		ports = 2;
 	else if (cpu_is_omap34xx())
 		ports = 3;
 	else if (cpu_is_omap44xx())
 		ports = 4;

 	return ports;
 }

 static inline int omap1_i2c_add_bus(int bus_id)
 {
 	struct platform_device *pdev;
 	struct omap_i2c_bus_platform_data *pdata;
 	struct resource *res;

 	omap1_i2c_mux_pins(bus_id);

 	pdev = &omap_i2c_devices[bus_id - 1];
 	res = pdev->resource;
 	res[0].start = OMAP1_I2C_BASE;
 	res[0].end = res[0].start + OMAP_I2C_SIZE;
 	res[1].start = OMAP1_INT_I2C;
 	pdata = &i2c_pdata[bus_id - 1];

 	/* all OMAP1 have IP version 1 register set */
 	pdata->rev = OMAP_I2C_IP_VERSION_1;

 	/* all OMAP1 I2C are implemented like this */
 	pdata->flags = OMAP_I2C_FLAG_NO_FIFO |
 		       OMAP_I2C_FLAG_SIMPLE_CLOCK |
 		       OMAP_I2C_FLAG_16BIT_DATA_REG |
 		       OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK;

 	/* how the cpu bus is wired up differs for 7xx only */

 	if (cpu_is_omap7xx())
 		pdata->flags |= OMAP_I2C_FLAG_BUS_SHIFT_1;
 	else
 		pdata->flags |= OMAP_I2C_FLAG_BUS_SHIFT_2;

 	return platform_device_register(pdev);
 }


 #ifdef CONFIG_ARCH_OMAP2PLUS
 /*
  * XXX This function is a temporary compatibility wrapper - only
  * needed until the I2C driver can be converted to call
  * omap_pm_set_max_dev_wakeup_lat() and handle a return code.
  */
 static void omap_pm_set_max_mpu_wakeup_lat_compat(struct device *dev, long t)
 {
 	omap_pm_set_max_mpu_wakeup_lat(dev, t);
 }

 static inline int omap2_i2c_add_bus(int bus_id)
 {
 	int l;
 	struct omap_hwmod *oh;
 	struct platform_device *pdev;
 	char oh_name[MAX_OMAP_I2C_HWMOD_NAME_LEN];
 	struct omap_i2c_bus_platform_data *pdata;
 	struct omap_i2c_dev_attr *dev_attr;

 	omap2_i2c_mux_pins(bus_id);

 	l = snprintf(oh_name, MAX_OMAP_I2C_HWMOD_NAME_LEN, "i2c%d", bus_id);
 	WARN(l >= MAX_OMAP_I2C_HWMOD_NAME_LEN,
 		"String buffer overflow in I2C%d device setup\n", bus_id);
 	oh = omap_hwmod_lookup(oh_name);
 	if (!oh) {
 			pr_err("Could not look up %s\n", oh_name);
 			return -EEXIST;
 	}

 	pdata = &i2c_pdata[bus_id - 1];
 	/*
 	 * pass the hwmod class's CPU-specific knowledge of I2C IP revision in
 	 * use, and functionality implementation flags, up to the OMAP I2C
 	 * driver via platform data
 	 */
 	pdata->rev = oh->class->rev;

 	dev_attr = (struct omap_i2c_dev_attr *)oh->dev_attr;
 	pdata->flags = dev_attr->flags;

 	/*
 	 * When waiting for completion of a i2c transfer, we need to
 	 * set a wake up latency constraint for the MPU. This is to
 	 * ensure quick enough wakeup from idle, when transfer
 	 * completes.
 	 * Only omap3 has support for constraints
 	 */
 	if (cpu_is_omap34xx())
 		pdata->set_mpu_wkup_lat = omap_pm_set_max_mpu_wakeup_lat_compat;
 	pdev = omap_device_build(name, bus_id, oh, pdata,
 			sizeof(struct omap_i2c_bus_platform_data),
 			NULL, 0, 0);
 	WARN(IS_ERR(pdev), "Could not build omap_device for %s\n", name);

 	return PTR_RET(pdev);
 }
 #else
 static inline int omap2_i2c_add_bus(int bus_id)
 {
 	return 0;
 }
 #endif

 static int __init omap_i2c_add_bus(int bus_id)
 {
 	if (cpu_class_is_omap1())
 		return omap1_i2c_add_bus(bus_id);
 	else
 		return omap2_i2c_add_bus(bus_id);
 }

 /**
  * omap_i2c_bus_setup - Process command line options for the I2C bus speed
  * @str: String of options
  *
  * This function allow to override the default I2C bus speed for given I2C
  * bus with a command line option.
  *
  * Format: i2c_bus=bus_id,clkrate (in kHz)
  *
  * Returns 1 on success, 0 otherwise.
  */
 static int __init omap_i2c_bus_setup(char *str)
 {
 	int ports;
 	int ints[3];

 	ports = omap_i2c_nr_ports();
 	get_options(str, 3, ints);
 	if (ints[0] < 2 || ints[1] < 1 || ints[1] > ports)
 		return 0;
 	i2c_pdata[ints[1] - 1].clkrate = ints[2];
 	i2c_pdata[ints[1] - 1].clkrate |= OMAP_I2C_CMDLINE_SETUP;

 	return 1;
 }
 __setup("i2c_bus=", omap_i2c_bus_setup);

 /*
  * Register busses defined in command line but that are not registered with
  * omap_register_i2c_bus from board initialization code.
  */
 static int __init omap_register_i2c_bus_cmdline(void)
 {
 	int i, err = 0;

 	for (i = 0; i < ARRAY_SIZE(i2c_pdata); i++)
 		if (i2c_pdata[i].clkrate & OMAP_I2C_CMDLINE_SETUP) {
 			i2c_pdata[i].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;
 			err = omap_i2c_add_bus(i + 1);
 			if (err)
 				goto out;
 		}

 out:
 	return err;
 }
 subsys_initcall(omap_register_i2c_bus_cmdline);

 /**
  * omap_register_i2c_bus - register I2C bus with device descriptors
  * @bus_id: bus id counting from number 1
  * @clkrate: clock rate of the bus in kHz
  * @info: pointer into I2C device descriptor table or NULL
  * @len: number of descriptors in the table
  *
  * Returns 0 on success or an error code.
  */
 int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
 			  struct i2c_board_info const *info,
 			  unsigned len)
 {
 	int err;

 	BUG_ON(bus_id < 1 || bus_id > omap_i2c_nr_ports());

 	if (info) {
 		err = i2c_register_board_info(bus_id, info, len);
 		if (err)
 			return err;
 	}

 	if (!i2c_pdata[bus_id - 1].clkrate)
 		i2c_pdata[bus_id - 1].clkrate = clkrate;

 	i2c_pdata[bus_id - 1].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;

 	return omap_i2c_add_bus(bus_id);
 }
	/*
	* linux/arch/arm/plat-omap/i2c.c
	*
	* Helper module for board specific I2C bus registration
	*
	* Copyright (C) 2007 Nokia Corporation.
	*
	* Contact: Jarkko Nikula <jhnikula@gmail.com>
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* version 2 as published by the Free Software Foundation.
	*
	* 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., 51 Franklin St, Fifth Floor, Boston, MA
	* 02110-1301 USA
	*
	*/

	#include <linux/kernel.h>
	#include <linux/platform_device.h>
	#include <linux/i2c.h>
	#include <linux/i2c-omap.h>
	#include <linux/slab.h>
	#include <linux/err.h>
	#include <linux/clk.h>

	#include <mach/irqs.h>
	#include <plat/i2c.h>
	#include <plat/omap-pm.h>
	#include <plat/omap_device.h>

	#define OMAP_I2C_SIZE 0x3f
	#define OMAP1_I2C_BASE 0xfffb3800
	#define OMAP1_INT_I2C (32 + 4)

	static const char name[] = "omap_i2c";

	#define I2C_RESOURCE_BUILDER(base, irq) \
	{ \
	.start = (base), \
	.end = (base) + OMAP_I2C_SIZE, \
	.flags = IORESOURCE_MEM, \
	}, \
	{ \
	.start = (irq), \
	.flags = IORESOURCE_IRQ, \
	},

	static struct resource i2c_resources[][2] = {
	{ I2C_RESOURCE_BUILDER(0, 0) },
	};

	#define I2C_DEV_BUILDER(bus_id, res, data) \
	{ \
	.id = (bus_id), \
	.name = name, \
	.num_resources = ARRAY_SIZE(res), \
	.resource = (res), \
	.dev = { \
	.platform_data = (data), \
	}, \
	}

	#define MAX_OMAP_I2C_HWMOD_NAME_LEN 16
	#define OMAP_I2C_MAX_CONTROLLERS 4
	static struct omap_i2c_bus_platform_data i2c_pdata[OMAP_I2C_MAX_CONTROLLERS];
	static struct platform_device omap_i2c_devices[] = {
	I2C_DEV_BUILDER(1, i2c_resources[0], &i2c_pdata[0]),
	};

	#define OMAP_I2C_CMDLINE_SETUP (BIT(31))

	static int __init omap_i2c_nr_ports(void)
	{
	int ports = 0;

	if (cpu_class_is_omap1())
	ports = 1;
	else if (cpu_is_omap24xx())
	ports = 2;
	else if (cpu_is_omap34xx())
	ports = 3;
	else if (cpu_is_omap44xx())
	ports = 4;

	return ports;
	}

	static inline int omap1_i2c_add_bus(int bus_id)
	{
	struct platform_device *pdev;
	struct omap_i2c_bus_platform_data *pdata;
	struct resource *res;

	omap1_i2c_mux_pins(bus_id);

	pdev = &omap_i2c_devices[bus_id - 1];
	res = pdev->resource;
	res[0].start = OMAP1_I2C_BASE;
	res[0].end = res[0].start + OMAP_I2C_SIZE;
	res[1].start = OMAP1_INT_I2C;
	pdata = &i2c_pdata[bus_id - 1];

	/* all OMAP1 have IP version 1 register set */
	pdata->rev = OMAP_I2C_IP_VERSION_1;

	/* all OMAP1 I2C are implemented like this */
	pdata->flags = OMAP_I2C_FLAG_NO_FIFO \|
	OMAP_I2C_FLAG_SIMPLE_CLOCK \|
	OMAP_I2C_FLAG_16BIT_DATA_REG \|
	OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK;

	/* how the cpu bus is wired up differs for 7xx only */

	if (cpu_is_omap7xx())
	pdata->flags \|= OMAP_I2C_FLAG_BUS_SHIFT_1;
	else
	pdata->flags \|= OMAP_I2C_FLAG_BUS_SHIFT_2;

	return platform_device_register(pdev);
	}


	#ifdef CONFIG_ARCH_OMAP2PLUS
	/*
	* XXX This function is a temporary compatibility wrapper - only
	* needed until the I2C driver can be converted to call
	* omap_pm_set_max_dev_wakeup_lat() and handle a return code.
	*/
	static void omap_pm_set_max_mpu_wakeup_lat_compat(struct device *dev, long t)
	{
	omap_pm_set_max_mpu_wakeup_lat(dev, t);
	}

	static inline int omap2_i2c_add_bus(int bus_id)
	{
	int l;
	struct omap_hwmod *oh;
	struct platform_device *pdev;
	char oh_name[MAX_OMAP_I2C_HWMOD_NAME_LEN];
	struct omap_i2c_bus_platform_data *pdata;
	struct omap_i2c_dev_attr *dev_attr;

	omap2_i2c_mux_pins(bus_id);

	l = snprintf(oh_name, MAX_OMAP_I2C_HWMOD_NAME_LEN, "i2c%d", bus_id);
	WARN(l >= MAX_OMAP_I2C_HWMOD_NAME_LEN,
	"String buffer overflow in I2C%d device setup\n", bus_id);
	oh = omap_hwmod_lookup(oh_name);
	if (!oh) {
	pr_err("Could not look up %s\n", oh_name);
	return -EEXIST;
	}

	pdata = &i2c_pdata[bus_id - 1];
	/*
	* pass the hwmod class's CPU-specific knowledge of I2C IP revision in
	* use, and functionality implementation flags, up to the OMAP I2C
	* driver via platform data
	*/
	pdata->rev = oh->class->rev;

	dev_attr = (struct omap_i2c_dev_attr *)oh->dev_attr;
	pdata->flags = dev_attr->flags;

	/*
	* When waiting for completion of a i2c transfer, we need to
	* set a wake up latency constraint for the MPU. This is to
	* ensure quick enough wakeup from idle, when transfer
	* completes.
	* Only omap3 has support for constraints
	*/
	if (cpu_is_omap34xx())
	pdata->set_mpu_wkup_lat = omap_pm_set_max_mpu_wakeup_lat_compat;
	pdev = omap_device_build(name, bus_id, oh, pdata,
	sizeof(struct omap_i2c_bus_platform_data),
	NULL, 0, 0);
	WARN(IS_ERR(pdev), "Could not build omap_device for %s\n", name);

	return PTR_RET(pdev);
	}
	#else
	static inline int omap2_i2c_add_bus(int bus_id)
	{
	return 0;
	}
	#endif

	static int __init omap_i2c_add_bus(int bus_id)
	{
	if (cpu_class_is_omap1())
	return omap1_i2c_add_bus(bus_id);
	else
	return omap2_i2c_add_bus(bus_id);
	}

	/**
	* omap_i2c_bus_setup - Process command line options for the I2C bus speed
	* @str: String of options
	*
	* This function allow to override the default I2C bus speed for given I2C
	* bus with a command line option.
	*
	* Format: i2c_bus=bus_id,clkrate (in kHz)
	*
	* Returns 1 on success, 0 otherwise.
	*/
	static int __init omap_i2c_bus_setup(char *str)
	{
	int ports;
	int ints[3];

	ports = omap_i2c_nr_ports();
	get_options(str, 3, ints);
	if (ints[0] < 2 \|\| ints[1] < 1 \|\| ints[1] > ports)
	return 0;
	i2c_pdata[ints[1] - 1].clkrate = ints[2];
	i2c_pdata[ints[1] - 1].clkrate \|= OMAP_I2C_CMDLINE_SETUP;

	return 1;
	}
	__setup("i2c_bus=", omap_i2c_bus_setup);

	/*
	* Register busses defined in command line but that are not registered with
	* omap_register_i2c_bus from board initialization code.
	*/
	static int __init omap_register_i2c_bus_cmdline(void)
	{
	int i, err = 0;

	for (i = 0; i < ARRAY_SIZE(i2c_pdata); i++)
	if (i2c_pdata[i].clkrate & OMAP_I2C_CMDLINE_SETUP) {
	i2c_pdata[i].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;
	err = omap_i2c_add_bus(i + 1);
	if (err)
	goto out;
	}

	out:
	return err;
	}
	subsys_initcall(omap_register_i2c_bus_cmdline);

	/**
	* omap_register_i2c_bus - register I2C bus with device descriptors
	* @bus_id: bus id counting from number 1
	* @clkrate: clock rate of the bus in kHz
	* @info: pointer into I2C device descriptor table or NULL
	* @len: number of descriptors in the table
	*
	* Returns 0 on success or an error code.
	*/
	int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
	struct i2c_board_info const *info,
	unsigned len)
	{
	int err;

	BUG_ON(bus_id < 1 \|\| bus_id > omap_i2c_nr_ports());

	if (info) {
	err = i2c_register_board_info(bus_id, info, len);
	if (err)
	return err;
	}

	if (!i2c_pdata[bus_id - 1].clkrate)
	i2c_pdata[bus_id - 1].clkrate = clkrate;

	i2c_pdata[bus_id - 1].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;

	return omap_i2c_add_bus(bus_id);
	}