drivers/mfd/twl4030-core.c - pub/scm/linux/kernel/git/linusw/linux-gpio - Git at Google

 /*
  * twl4030_core.c - driver for TWL4030/TPS659x0 PM and audio CODEC devices
  *
  * Copyright (C) 2005-2006 Texas Instruments, Inc.
  *
  * Modifications to defer interrupt handling to a kernel thread:
  * Copyright (C) 2006 MontaVista Software, Inc.
  *
  * Based on tlv320aic23.c:
  * Copyright (c) by Kai Svahn <kai.svahn@nokia.com>
  *
  * Code cleanup and modifications to IRQ handler.
  * by syed khasim <x0khasim@ti.com>
  *
  * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */

 #include <linux/init.h>
 #include <linux/mutex.h>
 #include <linux/platform_device.h>
 #include <linux/clk.h>
 #include <linux/err.h>

 #include <linux/i2c.h>
 #include <linux/i2c/twl4030.h>


 /*
  * The TWL4030 "Triton 2" is one of a family of a multi-function "Power
  * Management and System Companion Device" chips originally designed for
  * use in OMAP2 and OMAP 3 based systems.  Its control interfaces use I2C,
  * often at around 3 Mbit/sec, including for interrupt handling.
  *
  * This driver core provides genirq support for the interrupts emitted,
  * by the various modules, and exports register access primitives.
  *
  * FIXME this driver currently requires use of the first interrupt line
  * (and associated registers).
  */

 #define DRIVER_NAME			"twl4030"

 #if defined(CONFIG_TWL4030_BCI_BATTERY) || \
 	defined(CONFIG_TWL4030_BCI_BATTERY_MODULE)
 #define twl_has_bci()		true
 #else
 #define twl_has_bci()		false
 #endif

 #if defined(CONFIG_KEYBOARD_TWL4030) || defined(CONFIG_KEYBOARD_TWL4030_MODULE)
 #define twl_has_keypad()	true
 #else
 #define twl_has_keypad()	false
 #endif

 #if defined(CONFIG_GPIO_TWL4030) || defined(CONFIG_GPIO_TWL4030_MODULE)
 #define twl_has_gpio()	true
 #else
 #define twl_has_gpio()	false
 #endif

 #if defined(CONFIG_TWL4030_MADC) || defined(CONFIG_TWL4030_MADC_MODULE)
 #define twl_has_madc()	true
 #else
 #define twl_has_madc()	false
 #endif

 #if defined(CONFIG_RTC_DRV_TWL4030) || defined(CONFIG_RTC_DRV_TWL4030_MODULE)
 #define twl_has_rtc()	true
 #else
 #define twl_has_rtc()	false
 #endif

 #if defined(CONFIG_TWL4030_USB) || defined(CONFIG_TWL4030_USB_MODULE)
 #define twl_has_usb()	true
 #else
 #define twl_has_usb()	false
 #endif


 /* Triton Core internal information (BEGIN) */

 /* Last - for index max*/
 #define TWL4030_MODULE_LAST		TWL4030_MODULE_SECURED_REG

 #define TWL4030_NUM_SLAVES		4


 /* Base Address defns for twl4030_map[] */

 /* subchip/slave 0 - USB ID */
 #define TWL4030_BASEADD_USB		0x0000

 /* subchip/slave 1 - AUD ID */
 #define TWL4030_BASEADD_AUDIO_VOICE	0x0000
 #define TWL4030_BASEADD_GPIO		0x0098
 #define TWL4030_BASEADD_INTBR		0x0085
 #define TWL4030_BASEADD_PIH		0x0080
 #define TWL4030_BASEADD_TEST		0x004C

 /* subchip/slave 2 - AUX ID */
 #define TWL4030_BASEADD_INTERRUPTS	0x00B9
 #define TWL4030_BASEADD_LED		0x00EE
 #define TWL4030_BASEADD_MADC		0x0000
 #define TWL4030_BASEADD_MAIN_CHARGE	0x0074
 #define TWL4030_BASEADD_PRECHARGE	0x00AA
 #define TWL4030_BASEADD_PWM0		0x00F8
 #define TWL4030_BASEADD_PWM1		0x00FB
 #define TWL4030_BASEADD_PWMA		0x00EF
 #define TWL4030_BASEADD_PWMB		0x00F1
 #define TWL4030_BASEADD_KEYPAD		0x00D2

 /* subchip/slave 3 - POWER ID */
 #define TWL4030_BASEADD_BACKUP		0x0014
 #define TWL4030_BASEADD_INT		0x002E
 #define TWL4030_BASEADD_PM_MASTER	0x0036
 #define TWL4030_BASEADD_PM_RECEIVER	0x005B
 #define TWL4030_BASEADD_RTC		0x001C
 #define TWL4030_BASEADD_SECURED_REG	0x0000

 /* Triton Core internal information (END) */


 /* Few power values */
 #define R_CFG_BOOT			0x05
 #define R_PROTECT_KEY			0x0E

 /* access control values for R_PROTECT_KEY */
 #define KEY_UNLOCK1			0xce
 #define KEY_UNLOCK2			0xec
 #define KEY_LOCK			0x00

 /* some fields in R_CFG_BOOT */
 #define HFCLK_FREQ_19p2_MHZ		(1 << 0)
 #define HFCLK_FREQ_26_MHZ		(2 << 0)
 #define HFCLK_FREQ_38p4_MHZ		(3 << 0)
 #define HIGH_PERF_SQ			(1 << 3)


 /*----------------------------------------------------------------------*/

 /* is driver active, bound to a chip? */
 static bool inuse;

 /* Structure for each TWL4030 Slave */
 struct twl4030_client {
 	struct i2c_client *client;
 	u8 address;

 	/* max numb of i2c_msg required is for read =2 */
 	struct i2c_msg xfer_msg[2];

 	/* To lock access to xfer_msg */
 	struct mutex xfer_lock;
 };

 static struct twl4030_client twl4030_modules[TWL4030_NUM_SLAVES];


 /* mapping the module id to slave id and base address */
 struct twl4030mapping {
 	unsigned char sid;	/* Slave ID */
 	unsigned char base;	/* base address */
 };

 static struct twl4030mapping twl4030_map[TWL4030_MODULE_LAST + 1] = {
 	/*
 	 * NOTE:  don't change this table without updating the
 	 * <linux/i2c/twl4030.h> defines for TWL4030_MODULE_*
 	 * so they continue to match the order in this table.
 	 */

 	{ 0, TWL4030_BASEADD_USB },

 	{ 1, TWL4030_BASEADD_AUDIO_VOICE },
 	{ 1, TWL4030_BASEADD_GPIO },
 	{ 1, TWL4030_BASEADD_INTBR },
 	{ 1, TWL4030_BASEADD_PIH },
 	{ 1, TWL4030_BASEADD_TEST },

 	{ 2, TWL4030_BASEADD_KEYPAD },
 	{ 2, TWL4030_BASEADD_MADC },
 	{ 2, TWL4030_BASEADD_INTERRUPTS },
 	{ 2, TWL4030_BASEADD_LED },
 	{ 2, TWL4030_BASEADD_MAIN_CHARGE },
 	{ 2, TWL4030_BASEADD_PRECHARGE },
 	{ 2, TWL4030_BASEADD_PWM0 },
 	{ 2, TWL4030_BASEADD_PWM1 },
 	{ 2, TWL4030_BASEADD_PWMA },
 	{ 2, TWL4030_BASEADD_PWMB },

 	{ 3, TWL4030_BASEADD_BACKUP },
 	{ 3, TWL4030_BASEADD_INT },
 	{ 3, TWL4030_BASEADD_PM_MASTER },
 	{ 3, TWL4030_BASEADD_PM_RECEIVER },
 	{ 3, TWL4030_BASEADD_RTC },
 	{ 3, TWL4030_BASEADD_SECURED_REG },
 };

 /*----------------------------------------------------------------------*/

 /* Exported Functions */

 /**
  * twl4030_i2c_write - Writes a n bit register in TWL4030
  * @mod_no: module number
  * @value: an array of num_bytes+1 containing data to write
  * @reg: register address (just offset will do)
  * @num_bytes: number of bytes to transfer
  *
  * IMPORTANT: for 'value' parameter: Allocate value num_bytes+1 and
  * valid data starts at Offset 1.
  *
  * Returns the result of operation - 0 is success
  */
 int twl4030_i2c_write(u8 mod_no, u8 *value, u8 reg, u8 num_bytes)
 {
 	int ret;
 	int sid;
 	struct twl4030_client *twl;
 	struct i2c_msg *msg;

 	if (unlikely(mod_no > TWL4030_MODULE_LAST)) {
 		pr_err("%s: invalid module number %d\n", DRIVER_NAME, mod_no);
 		return -EPERM;
 	}
 	sid = twl4030_map[mod_no].sid;
 	twl = &twl4030_modules[sid];

 	if (unlikely(!inuse)) {
 		pr_err("%s: client %d is not initialized\n", DRIVER_NAME, sid);
 		return -EPERM;
 	}
 	mutex_lock(&twl->xfer_lock);
 	/*
 	 * [MSG1]: fill the register address data
 	 * fill the data Tx buffer
 	 */
 	msg = &twl->xfer_msg[0];
 	msg->addr = twl->address;
 	msg->len = num_bytes + 1;
 	msg->flags = 0;
 	msg->buf = value;
 	/* over write the first byte of buffer with the register address */
 	*value = twl4030_map[mod_no].base + reg;
 	ret = i2c_transfer(twl->client->adapter, twl->xfer_msg, 1);
 	mutex_unlock(&twl->xfer_lock);

 	/* i2cTransfer returns num messages.translate it pls.. */
 	if (ret >= 0)
 		ret = 0;
 	return ret;
 }
 EXPORT_SYMBOL(twl4030_i2c_write);

 /**
  * twl4030_i2c_read - Reads a n bit register in TWL4030
  * @mod_no: module number
  * @value: an array of num_bytes containing data to be read
  * @reg: register address (just offset will do)
  * @num_bytes: number of bytes to transfer
  *
  * Returns result of operation - num_bytes is success else failure.
  */
 int twl4030_i2c_read(u8 mod_no, u8 *value, u8 reg, u8 num_bytes)
 {
 	int ret;
 	u8 val;
 	int sid;
 	struct twl4030_client *twl;
 	struct i2c_msg *msg;

 	if (unlikely(mod_no > TWL4030_MODULE_LAST)) {
 		pr_err("%s: invalid module number %d\n", DRIVER_NAME, mod_no);
 		return -EPERM;
 	}
 	sid = twl4030_map[mod_no].sid;
 	twl = &twl4030_modules[sid];

 	if (unlikely(!inuse)) {
 		pr_err("%s: client %d is not initialized\n", DRIVER_NAME, sid);
 		return -EPERM;
 	}
 	mutex_lock(&twl->xfer_lock);
 	/* [MSG1] fill the register address data */
 	msg = &twl->xfer_msg[0];
 	msg->addr = twl->address;
 	msg->len = 1;
 	msg->flags = 0;	/* Read the register value */
 	val = twl4030_map[mod_no].base + reg;
 	msg->buf = &val;
 	/* [MSG2] fill the data rx buffer */
 	msg = &twl->xfer_msg[1];
 	msg->addr = twl->address;
 	msg->flags = I2C_M_RD;	/* Read the register value */
 	msg->len = num_bytes;	/* only n bytes */
 	msg->buf = value;
 	ret = i2c_transfer(twl->client->adapter, twl->xfer_msg, 2);
 	mutex_unlock(&twl->xfer_lock);

 	/* i2cTransfer returns num messages.translate it pls.. */
 	if (ret >= 0)
 		ret = 0;
 	return ret;
 }
 EXPORT_SYMBOL(twl4030_i2c_read);

 /**
  * twl4030_i2c_write_u8 - Writes a 8 bit register in TWL4030
  * @mod_no: module number
  * @value: the value to be written 8 bit
  * @reg: register address (just offset will do)
  *
  * Returns result of operation - 0 is success
  */
 int twl4030_i2c_write_u8(u8 mod_no, u8 value, u8 reg)
 {

 	/* 2 bytes offset 1 contains the data offset 0 is used by i2c_write */
 	u8 temp_buffer[2] = { 0 };
 	/* offset 1 contains the data */
 	temp_buffer[1] = value;
 	return twl4030_i2c_write(mod_no, temp_buffer, reg, 1);
 }
 EXPORT_SYMBOL(twl4030_i2c_write_u8);

 /**
  * twl4030_i2c_read_u8 - Reads a 8 bit register from TWL4030
  * @mod_no: module number
  * @value: the value read 8 bit
  * @reg: register address (just offset will do)
  *
  * Returns result of operation - 0 is success
  */
 int twl4030_i2c_read_u8(u8 mod_no, u8 *value, u8 reg)
 {
 	return twl4030_i2c_read(mod_no, value, reg, 1);
 }
 EXPORT_SYMBOL(twl4030_i2c_read_u8);

 /*----------------------------------------------------------------------*/

 /*
  * NOTE:  We know the first 8 IRQs after pdata->base_irq are
  * for the PIH, and the next are for the PWR_INT SIH, since
  * that's how twl_init_irq() sets things up.
  */

 static int add_children(struct twl4030_platform_data *pdata)
 {
 	struct platform_device	*pdev = NULL;
 	struct twl4030_client	*twl = NULL;
 	int			status = 0;

 	if (twl_has_bci() && pdata->bci) {
 		twl = &twl4030_modules[3];

 		pdev = platform_device_alloc("twl4030_bci", -1);
 		if (!pdev) {
 			pr_debug("%s: can't alloc bci dev\n", DRIVER_NAME);
 			status = -ENOMEM;
 			goto err;
 		}

 		if (status == 0) {
 			pdev->dev.parent = &twl->client->dev;
 			status = platform_device_add_data(pdev, pdata->bci,
 					sizeof(*pdata->bci));
 			if (status < 0) {
 				dev_dbg(&twl->client->dev,
 					"can't add bci data, %d\n",
 					status);
 				goto err;
 			}
 		}

 		if (status == 0) {
 			struct resource r = {
 				.start = pdata->irq_base + 8 + 1,
 				.flags = IORESOURCE_IRQ,
 			};

 			status = platform_device_add_resources(pdev, &r, 1);
 		}

 		if (status == 0)
 			status = platform_device_add(pdev);

 		if (status < 0) {
 			platform_device_put(pdev);
 			dev_dbg(&twl->client->dev,
 					"can't create bci dev, %d\n",
 					status);
 			goto err;
 		}
 	}

 	if (twl_has_gpio() && pdata->gpio) {
 		twl = &twl4030_modules[1];

 		pdev = platform_device_alloc("twl4030_gpio", -1);
 		if (!pdev) {
 			pr_debug("%s: can't alloc gpio dev\n", DRIVER_NAME);
 			status = -ENOMEM;
 			goto err;
 		}

 		/* more driver model init */
 		if (status == 0) {
 			pdev->dev.parent = &twl->client->dev;
 			/* device_init_wakeup(&pdev->dev, 1); */

 			status = platform_device_add_data(pdev, pdata->gpio,
 					sizeof(*pdata->gpio));
 			if (status < 0) {
 				dev_dbg(&twl->client->dev,
 					"can't add gpio data, %d\n",
 					status);
 				goto err;
 			}
 		}

 		/* GPIO module IRQ */
 		if (status == 0) {
 			struct resource	r = {
 				.start = pdata->irq_base + 0,
 				.flags = IORESOURCE_IRQ,
 			};

 			status = platform_device_add_resources(pdev, &r, 1);
 		}

 		if (status == 0)
 			status = platform_device_add(pdev);

 		if (status < 0) {
 			platform_device_put(pdev);
 			dev_dbg(&twl->client->dev,
 					"can't create gpio dev, %d\n",
 					status);
 			goto err;
 		}
 	}

 	if (twl_has_keypad() && pdata->keypad) {
 		pdev = platform_device_alloc("twl4030_keypad", -1);
 		if (pdev) {
 			twl = &twl4030_modules[2];
 			pdev->dev.parent = &twl->client->dev;
 			device_init_wakeup(&pdev->dev, 1);
 			status = platform_device_add_data(pdev, pdata->keypad,
 					sizeof(*pdata->keypad));
 			if (status < 0) {
 				dev_dbg(&twl->client->dev,
 					"can't add keypad data, %d\n",
 					status);
 				platform_device_put(pdev);
 				goto err;
 			}
 			status = platform_device_add(pdev);
 			if (status < 0) {
 				platform_device_put(pdev);
 				dev_dbg(&twl->client->dev,
 						"can't create keypad dev, %d\n",
 						status);
 				goto err;
 			}
 		} else {
 			pr_debug("%s: can't alloc keypad dev\n", DRIVER_NAME);
 			status = -ENOMEM;
 			goto err;
 		}
 	}

 	if (twl_has_madc() && pdata->madc) {
 		pdev = platform_device_alloc("twl4030_madc", -1);
 		if (pdev) {
 			twl = &twl4030_modules[2];
 			pdev->dev.parent = &twl->client->dev;
 			device_init_wakeup(&pdev->dev, 1);
 			status = platform_device_add_data(pdev, pdata->madc,
 					sizeof(*pdata->madc));
 			if (status < 0) {
 				platform_device_put(pdev);
 				dev_dbg(&twl->client->dev,
 					"can't add madc data, %d\n",
 					status);
 				goto err;
 			}
 			status = platform_device_add(pdev);
 			if (status < 0) {
 				platform_device_put(pdev);
 				dev_dbg(&twl->client->dev,
 						"can't create madc dev, %d\n",
 						status);
 				goto err;
 			}
 		} else {
 			pr_debug("%s: can't alloc madc dev\n", DRIVER_NAME);
 			status = -ENOMEM;
 			goto err;
 		}
 	}

 	if (twl_has_rtc()) {
 		twl = &twl4030_modules[3];

 		pdev = platform_device_alloc("twl4030_rtc", -1);
 		if (!pdev) {
 			pr_debug("%s: can't alloc rtc dev\n", DRIVER_NAME);
 			status = -ENOMEM;
 		} else {
 			pdev->dev.parent = &twl->client->dev;
 			device_init_wakeup(&pdev->dev, 1);
 		}

 		/*
 		 * REVISIT platform_data here currently might use of
 		 * "msecure" line ... but for now we just expect board
 		 * setup to tell the chip "we are secure" at all times.
 		 * Eventually, Linux might become more aware of such
 		 * HW security concerns, and "least privilege".
 		 */

 		/* RTC module IRQ */
 		if (status == 0) {
 			struct resource	r = {
 				.start = pdata->irq_base + 8 + 3,
 				.flags = IORESOURCE_IRQ,
 			};

 			status = platform_device_add_resources(pdev, &r, 1);
 		}

 		if (status == 0)
 			status = platform_device_add(pdev);

 		if (status < 0) {
 			platform_device_put(pdev);
 			dev_dbg(&twl->client->dev,
 					"can't create rtc dev, %d\n",
 					status);
 			goto err;
 		}
 	}

 	if (twl_has_usb() && pdata->usb) {
 		twl = &twl4030_modules[0];

 		pdev = platform_device_alloc("twl4030_usb", -1);
 		if (!pdev) {
 			pr_debug("%s: can't alloc usb dev\n", DRIVER_NAME);
 			status = -ENOMEM;
 			goto err;
 		}

 		if (status == 0) {
 			pdev->dev.parent = &twl->client->dev;
 			device_init_wakeup(&pdev->dev, 1);
 			status = platform_device_add_data(pdev, pdata->usb,
 					sizeof(*pdata->usb));
 			if (status < 0) {
 				platform_device_put(pdev);
 				dev_dbg(&twl->client->dev,
 					"can't add usb data, %d\n",
 					status);
 				goto err;
 			}
 		}

 		if (status == 0) {
 			struct resource r = {
 				.start = pdata->irq_base + 8 + 2,
 				.flags = IORESOURCE_IRQ,
 			};

 			status = platform_device_add_resources(pdev, &r, 1);
 		}

 		if (status == 0)
 			status = platform_device_add(pdev);

 		if (status < 0) {
 			platform_device_put(pdev);
 			dev_dbg(&twl->client->dev,
 					"can't create usb dev, %d\n",
 					status);
 		}
 	}

 err:
 	if (status)
 		pr_err("failed to add twl4030's children (status %d)\n", status);
 	return status;
 }

 /*----------------------------------------------------------------------*/

 /*
  * These three functions initialize the on-chip clock framework,
  * letting it generate the right frequencies for USB, MADC, and
  * other purposes.
  */
 static inline int __init protect_pm_master(void)
 {
 	int e = 0;

 	e = twl4030_i2c_write_u8(TWL4030_MODULE_PM_MASTER, KEY_LOCK,
 			R_PROTECT_KEY);
 	return e;
 }

 static inline int __init unprotect_pm_master(void)
 {
 	int e = 0;

 	e |= twl4030_i2c_write_u8(TWL4030_MODULE_PM_MASTER, KEY_UNLOCK1,
 			R_PROTECT_KEY);
 	e |= twl4030_i2c_write_u8(TWL4030_MODULE_PM_MASTER, KEY_UNLOCK2,
 			R_PROTECT_KEY);
 	return e;
 }

 static void __init clocks_init(void)
 {
 	int e = 0;
 	struct clk *osc;
 	u32 rate;
 	u8 ctrl = HFCLK_FREQ_26_MHZ;

 #if defined(CONFIG_ARCH_OMAP2) || defined(CONFIG_ARCH_OMAP3)
 	if (cpu_is_omap2430())
 		osc = clk_get(NULL, "osc_ck");
 	else
 		osc = clk_get(NULL, "osc_sys_ck");
 #else
 	/* REVISIT for non-OMAP systems, pass the clock rate from
 	 * board init code, using platform_data.
 	 */
 	osc = ERR_PTR(-EIO);
 #endif
 	if (IS_ERR(osc)) {
 		printk(KERN_WARNING "Skipping twl4030 internal clock init and "
 				"using bootloader value (unknown osc rate)\n");
 		return;
 	}

 	rate = clk_get_rate(osc);
 	clk_put(osc);

 	switch (rate) {
 	case 19200000:
 		ctrl = HFCLK_FREQ_19p2_MHZ;
 		break;
 	case 26000000:
 		ctrl = HFCLK_FREQ_26_MHZ;
 		break;
 	case 38400000:
 		ctrl = HFCLK_FREQ_38p4_MHZ;
 		break;
 	}

 	ctrl |= HIGH_PERF_SQ;
 	e |= unprotect_pm_master();
 	/* effect->MADC+USB ck en */
 	e |= twl4030_i2c_write_u8(TWL4030_MODULE_PM_MASTER, ctrl, R_CFG_BOOT);
 	e |= protect_pm_master();

 	if (e < 0)
 		pr_err("%s: clock init err [%d]\n", DRIVER_NAME, e);
 }

 /*----------------------------------------------------------------------*/

 int twl_init_irq(int irq_num, unsigned irq_base, unsigned irq_end);
 int twl_exit_irq(void);

 static int twl4030_remove(struct i2c_client *client)
 {
 	unsigned i;
 	int status;

 	status = twl_exit_irq();
 	if (status < 0)
 		return status;

 	for (i = 0; i < TWL4030_NUM_SLAVES; i++) {
 		struct twl4030_client	*twl = &twl4030_modules[i];

 		if (twl->client && twl->client != client)
 			i2c_unregister_device(twl->client);
 		twl4030_modules[i].client = NULL;
 	}
 	inuse = false;
 	return 0;
 }

 /* NOTE:  this driver only handles a single twl4030/tps659x0 chip */
 static int
 twl4030_probe(struct i2c_client *client, const struct i2c_device_id *id)
 {
 	int				status;
 	unsigned			i;
 	struct twl4030_platform_data	*pdata = client->dev.platform_data;

 	if (!pdata) {
 		dev_dbg(&client->dev, "no platform data?\n");
 		return -EINVAL;
 	}

 	if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C) == 0) {
 		dev_dbg(&client->dev, "can't talk I2C?\n");
 		return -EIO;
 	}

 	if (inuse) {
 		dev_dbg(&client->dev, "driver is already in use\n");
 		return -EBUSY;
 	}

 	for (i = 0; i < TWL4030_NUM_SLAVES; i++) {
 		struct twl4030_client	*twl = &twl4030_modules[i];

 		twl->address = client->addr + i;
 		if (i == 0)
 			twl->client = client;
 		else {
 			twl->client = i2c_new_dummy(client->adapter,
 					twl->address);
 			if (!twl->client) {
 				dev_err(&twl->client->dev,
 					"can't attach client %d\n", i);
 				status = -ENOMEM;
 				goto fail;
 			}
 			strlcpy(twl->client->name, id->name,
 					sizeof(twl->client->name));
 		}
 		mutex_init(&twl->xfer_lock);
 	}
 	inuse = true;

 	/* setup clock framework */
 	clocks_init();

 	/* Maybe init the T2 Interrupt subsystem */
 	if (client->irq
 			&& pdata->irq_base
 			&& pdata->irq_end > pdata->irq_base) {
 		status = twl_init_irq(client->irq, pdata->irq_base, pdata->irq_end);
 		if (status < 0)
 			goto fail;
 	}

 	status = add_children(pdata);
 fail:
 	if (status < 0)
 		twl4030_remove(client);
 	return status;
 }

 static const struct i2c_device_id twl4030_ids[] = {
 	{ "twl4030", 0 },	/* "Triton 2" */
 	{ "tps65950", 0 },	/* catalog version of twl4030 */
 	{ "tps65930", 0 },	/* fewer LDOs and DACs; no charger */
 	{ "tps65920", 0 },	/* fewer LDOs; no codec or charger */
 	{ "twl5030", 0 },	/* T2 updated */
 	{ /* end of list */ },
 };
 MODULE_DEVICE_TABLE(i2c, twl4030_ids);

 /* One Client Driver , 4 Clients */
 static struct i2c_driver twl4030_driver = {
 	.driver.name	= DRIVER_NAME,
 	.id_table	= twl4030_ids,
 	.probe		= twl4030_probe,
 	.remove		= twl4030_remove,
 };

 static int __init twl4030_init(void)
 {
 	return i2c_add_driver(&twl4030_driver);
 }
 subsys_initcall(twl4030_init);

 static void __exit twl4030_exit(void)
 {
 	i2c_del_driver(&twl4030_driver);
 }
 module_exit(twl4030_exit);

 MODULE_AUTHOR("Texas Instruments, Inc.");
 MODULE_DESCRIPTION("I2C Core interface for TWL4030");
 MODULE_LICENSE("GPL");
	/*
	* twl4030_core.c - driver for TWL4030/TPS659x0 PM and audio CODEC devices
	*
	* Copyright (C) 2005-2006 Texas Instruments, Inc.
	*
	* Modifications to defer interrupt handling to a kernel thread:
	* Copyright (C) 2006 MontaVista Software, Inc.
	*
	* Based on tlv320aic23.c:
	* Copyright (c) by Kai Svahn <kai.svahn@nokia.com>
	*
	* Code cleanup and modifications to IRQ handler.
	* by syed khasim <x0khasim@ti.com>
	*
	* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#include <linux/init.h>
	#include <linux/mutex.h>
	#include <linux/platform_device.h>
	#include <linux/clk.h>
	#include <linux/err.h>

	#include <linux/i2c.h>
	#include <linux/i2c/twl4030.h>


	/*
	* The TWL4030 "Triton 2" is one of a family of a multi-function "Power
	* Management and System Companion Device" chips originally designed for
	* use in OMAP2 and OMAP 3 based systems. Its control interfaces use I2C,
	* often at around 3 Mbit/sec, including for interrupt handling.
	*
	* This driver core provides genirq support for the interrupts emitted,
	* by the various modules, and exports register access primitives.
	*
	* FIXME this driver currently requires use of the first interrupt line
	* (and associated registers).
	*/

	#define DRIVER_NAME "twl4030"

	#if defined(CONFIG_TWL4030_BCI_BATTERY) \|\| \
	defined(CONFIG_TWL4030_BCI_BATTERY_MODULE)
	#define twl_has_bci() true
	#else
	#define twl_has_bci() false
	#endif

	#if defined(CONFIG_KEYBOARD_TWL4030) \|\| defined(CONFIG_KEYBOARD_TWL4030_MODULE)
	#define twl_has_keypad() true
	#else
	#define twl_has_keypad() false
	#endif

	#if defined(CONFIG_GPIO_TWL4030) \|\| defined(CONFIG_GPIO_TWL4030_MODULE)
	#define twl_has_gpio() true
	#else
	#define twl_has_gpio() false
	#endif

	#if defined(CONFIG_TWL4030_MADC) \|\| defined(CONFIG_TWL4030_MADC_MODULE)
	#define twl_has_madc() true
	#else
	#define twl_has_madc() false
	#endif

	#if defined(CONFIG_RTC_DRV_TWL4030) \|\| defined(CONFIG_RTC_DRV_TWL4030_MODULE)
	#define twl_has_rtc() true
	#else
	#define twl_has_rtc() false
	#endif

	#if defined(CONFIG_TWL4030_USB) \|\| defined(CONFIG_TWL4030_USB_MODULE)
	#define twl_has_usb() true
	#else
	#define twl_has_usb() false
	#endif


	/* Triton Core internal information (BEGIN) */

	/* Last - for index max*/
	#define TWL4030_MODULE_LAST TWL4030_MODULE_SECURED_REG

	#define TWL4030_NUM_SLAVES 4


	/* Base Address defns for twl4030_map[] */

	/* subchip/slave 0 - USB ID */
	#define TWL4030_BASEADD_USB 0x0000

	/* subchip/slave 1 - AUD ID */
	#define TWL4030_BASEADD_AUDIO_VOICE 0x0000
	#define TWL4030_BASEADD_GPIO 0x0098
	#define TWL4030_BASEADD_INTBR 0x0085
	#define TWL4030_BASEADD_PIH 0x0080
	#define TWL4030_BASEADD_TEST 0x004C

	/* subchip/slave 2 - AUX ID */
	#define TWL4030_BASEADD_INTERRUPTS 0x00B9
	#define TWL4030_BASEADD_LED 0x00EE
	#define TWL4030_BASEADD_MADC 0x0000
	#define TWL4030_BASEADD_MAIN_CHARGE 0x0074
	#define TWL4030_BASEADD_PRECHARGE 0x00AA
	#define TWL4030_BASEADD_PWM0 0x00F8
	#define TWL4030_BASEADD_PWM1 0x00FB
	#define TWL4030_BASEADD_PWMA 0x00EF
	#define TWL4030_BASEADD_PWMB 0x00F1
	#define TWL4030_BASEADD_KEYPAD 0x00D2

	/* subchip/slave 3 - POWER ID */
	#define TWL4030_BASEADD_BACKUP 0x0014
	#define TWL4030_BASEADD_INT 0x002E
	#define TWL4030_BASEADD_PM_MASTER 0x0036
	#define TWL4030_BASEADD_PM_RECEIVER 0x005B
	#define TWL4030_BASEADD_RTC 0x001C
	#define TWL4030_BASEADD_SECURED_REG 0x0000

	/* Triton Core internal information (END) */


	/* Few power values */
	#define R_CFG_BOOT 0x05
	#define R_PROTECT_KEY 0x0E

	/* access control values for R_PROTECT_KEY */
	#define KEY_UNLOCK1 0xce
	#define KEY_UNLOCK2 0xec
	#define KEY_LOCK 0x00

	/* some fields in R_CFG_BOOT */
	#define HFCLK_FREQ_19p2_MHZ (1 << 0)
	#define HFCLK_FREQ_26_MHZ (2 << 0)
	#define HFCLK_FREQ_38p4_MHZ (3 << 0)
	#define HIGH_PERF_SQ (1 << 3)


	/----------------------------------------------------------------------/

	/* is driver active, bound to a chip? */
	static bool inuse;

	/* Structure for each TWL4030 Slave */
	struct twl4030_client {
	struct i2c_client *client;
	u8 address;

	/* max numb of i2c_msg required is for read =2 */
	struct i2c_msg xfer_msg[2];

	/* To lock access to xfer_msg */
	struct mutex xfer_lock;
	};

	static struct twl4030_client twl4030_modules[TWL4030_NUM_SLAVES];


	/* mapping the module id to slave id and base address */
	struct twl4030mapping {
	unsigned char sid; /* Slave ID */
	unsigned char base; /* base address */
	};

	static struct twl4030mapping twl4030_map[TWL4030_MODULE_LAST + 1] = {
	/*
	* NOTE: don't change this table without updating the
	* <linux/i2c/twl4030.h> defines for TWL4030_MODULE_*
	* so they continue to match the order in this table.
	*/

	{ 0, TWL4030_BASEADD_USB },

	{ 1, TWL4030_BASEADD_AUDIO_VOICE },
	{ 1, TWL4030_BASEADD_GPIO },
	{ 1, TWL4030_BASEADD_INTBR },
	{ 1, TWL4030_BASEADD_PIH },
	{ 1, TWL4030_BASEADD_TEST },

	{ 2, TWL4030_BASEADD_KEYPAD },
	{ 2, TWL4030_BASEADD_MADC },
	{ 2, TWL4030_BASEADD_INTERRUPTS },
	{ 2, TWL4030_BASEADD_LED },
	{ 2, TWL4030_BASEADD_MAIN_CHARGE },
	{ 2, TWL4030_BASEADD_PRECHARGE },
	{ 2, TWL4030_BASEADD_PWM0 },
	{ 2, TWL4030_BASEADD_PWM1 },
	{ 2, TWL4030_BASEADD_PWMA },
	{ 2, TWL4030_BASEADD_PWMB },

	{ 3, TWL4030_BASEADD_BACKUP },
	{ 3, TWL4030_BASEADD_INT },
	{ 3, TWL4030_BASEADD_PM_MASTER },
	{ 3, TWL4030_BASEADD_PM_RECEIVER },
	{ 3, TWL4030_BASEADD_RTC },
	{ 3, TWL4030_BASEADD_SECURED_REG },
	};

	/----------------------------------------------------------------------/

	/* Exported Functions */

	/**
	* twl4030_i2c_write - Writes a n bit register in TWL4030
	* @mod_no: module number
	* @value: an array of num_bytes+1 containing data to write
	* @reg: register address (just offset will do)
	* @num_bytes: number of bytes to transfer
	*
	* IMPORTANT: for 'value' parameter: Allocate value num_bytes+1 and
	* valid data starts at Offset 1.
	*
	* Returns the result of operation - 0 is success
	*/
	int twl4030_i2c_write(u8 mod_no, u8 *value, u8 reg, u8 num_bytes)
	{
	int ret;
	int sid;
	struct twl4030_client *twl;
	struct i2c_msg *msg;

	if (unlikely(mod_no > TWL4030_MODULE_LAST)) {
	pr_err("%s: invalid module number %d\n", DRIVER_NAME, mod_no);
	return -EPERM;
	}
	sid = twl4030_map[mod_no].sid;
	twl = &twl4030_modules[sid];

	if (unlikely(!inuse)) {
	pr_err("%s: client %d is not initialized\n", DRIVER_NAME, sid);
	return -EPERM;
	}
	mutex_lock(&twl->xfer_lock);
	/*
	* [MSG1]: fill the register address data
	* fill the data Tx buffer
	*/
	msg = &twl->xfer_msg[0];
	msg->addr = twl->address;
	msg->len = num_bytes + 1;
	msg->flags = 0;
	msg->buf = value;
	/* over write the first byte of buffer with the register address */
	*value = twl4030_map[mod_no].base + reg;
	ret = i2c_transfer(twl->client->adapter, twl->xfer_msg, 1);
	mutex_unlock(&twl->xfer_lock);

	/* i2cTransfer returns num messages.translate it pls.. */
	if (ret >= 0)
	ret = 0;
	return ret;
	}
	EXPORT_SYMBOL(twl4030_i2c_write);

	/**
	* twl4030_i2c_read - Reads a n bit register in TWL4030
	* @mod_no: module number
	* @value: an array of num_bytes containing data to be read
	* @reg: register address (just offset will do)
	* @num_bytes: number of bytes to transfer
	*
	* Returns result of operation - num_bytes is success else failure.
	*/
	int twl4030_i2c_read(u8 mod_no, u8 *value, u8 reg, u8 num_bytes)
	{
	int ret;
	u8 val;
	int sid;
	struct twl4030_client *twl;
	struct i2c_msg *msg;

	if (unlikely(mod_no > TWL4030_MODULE_LAST)) {
	pr_err("%s: invalid module number %d\n", DRIVER_NAME, mod_no);
	return -EPERM;
	}
	sid = twl4030_map[mod_no].sid;
	twl = &twl4030_modules[sid];

	if (unlikely(!inuse)) {
	pr_err("%s: client %d is not initialized\n", DRIVER_NAME, sid);
	return -EPERM;
	}
	mutex_lock(&twl->xfer_lock);
	/* [MSG1] fill the register address data */
	msg = &twl->xfer_msg[0];
	msg->addr = twl->address;
	msg->len = 1;
	msg->flags = 0; /* Read the register value */
	val = twl4030_map[mod_no].base + reg;
	msg->buf = &val;
	/* [MSG2] fill the data rx buffer */
	msg = &twl->xfer_msg[1];
	msg->addr = twl->address;
	msg->flags = I2C_M_RD; /* Read the register value */
	msg->len = num_bytes; /* only n bytes */
	msg->buf = value;
	ret = i2c_transfer(twl->client->adapter, twl->xfer_msg, 2);
	mutex_unlock(&twl->xfer_lock);

	/* i2cTransfer returns num messages.translate it pls.. */
	if (ret >= 0)
	ret = 0;
	return ret;
	}
	EXPORT_SYMBOL(twl4030_i2c_read);

	/**
	* twl4030_i2c_write_u8 - Writes a 8 bit register in TWL4030
	* @mod_no: module number
	* @value: the value to be written 8 bit
	* @reg: register address (just offset will do)
	*
	* Returns result of operation - 0 is success
	*/
	int twl4030_i2c_write_u8(u8 mod_no, u8 value, u8 reg)
	{

	/* 2 bytes offset 1 contains the data offset 0 is used by i2c_write */
	u8 temp_buffer[2] = { 0 };
	/* offset 1 contains the data */
	temp_buffer[1] = value;
	return twl4030_i2c_write(mod_no, temp_buffer, reg, 1);
	}
	EXPORT_SYMBOL(twl4030_i2c_write_u8);

	/**
	* twl4030_i2c_read_u8 - Reads a 8 bit register from TWL4030
	* @mod_no: module number
	* @value: the value read 8 bit
	* @reg: register address (just offset will do)
	*
	* Returns result of operation - 0 is success
	*/
	int twl4030_i2c_read_u8(u8 mod_no, u8 *value, u8 reg)
	{
	return twl4030_i2c_read(mod_no, value, reg, 1);
	}
	EXPORT_SYMBOL(twl4030_i2c_read_u8);

	/----------------------------------------------------------------------/

	/*
	* NOTE: We know the first 8 IRQs after pdata->base_irq are
	* for the PIH, and the next are for the PWR_INT SIH, since
	* that's how twl_init_irq() sets things up.
	*/

	static int add_children(struct twl4030_platform_data *pdata)
	{
	struct platform_device *pdev = NULL;
	struct twl4030_client *twl = NULL;
	int status = 0;

	if (twl_has_bci() && pdata->bci) {
	twl = &twl4030_modules[3];

	pdev = platform_device_alloc("twl4030_bci", -1);
	if (!pdev) {
	pr_debug("%s: can't alloc bci dev\n", DRIVER_NAME);
	status = -ENOMEM;
	goto err;
	}

	if (status == 0) {
	pdev->dev.parent = &twl->client->dev;
	status = platform_device_add_data(pdev, pdata->bci,
	sizeof(*pdata->bci));
	if (status < 0) {
	dev_dbg(&twl->client->dev,
	"can't add bci data, %d\n",
	status);
	goto err;
	}
	}

	if (status == 0) {
	struct resource r = {
	.start = pdata->irq_base + 8 + 1,
	.flags = IORESOURCE_IRQ,
	};

	status = platform_device_add_resources(pdev, &r, 1);
	}

	if (status == 0)
	status = platform_device_add(pdev);

	if (status < 0) {
	platform_device_put(pdev);
	dev_dbg(&twl->client->dev,
	"can't create bci dev, %d\n",
	status);
	goto err;
	}
	}

	if (twl_has_gpio() && pdata->gpio) {
	twl = &twl4030_modules[1];

	pdev = platform_device_alloc("twl4030_gpio", -1);
	if (!pdev) {
	pr_debug("%s: can't alloc gpio dev\n", DRIVER_NAME);
	status = -ENOMEM;
	goto err;
	}

	/* more driver model init */
	if (status == 0) {
	pdev->dev.parent = &twl->client->dev;
	/* device_init_wakeup(&pdev->dev, 1); */

	status = platform_device_add_data(pdev, pdata->gpio,
	sizeof(*pdata->gpio));
	if (status < 0) {
	dev_dbg(&twl->client->dev,
	"can't add gpio data, %d\n",
	status);
	goto err;
	}
	}

	/* GPIO module IRQ */
	if (status == 0) {
	struct resource r = {
	.start = pdata->irq_base + 0,
	.flags = IORESOURCE_IRQ,
	};

	status = platform_device_add_resources(pdev, &r, 1);
	}

	if (status == 0)
	status = platform_device_add(pdev);

	if (status < 0) {
	platform_device_put(pdev);
	dev_dbg(&twl->client->dev,
	"can't create gpio dev, %d\n",
	status);
	goto err;
	}
	}

	if (twl_has_keypad() && pdata->keypad) {
	pdev = platform_device_alloc("twl4030_keypad", -1);
	if (pdev) {
	twl = &twl4030_modules[2];
	pdev->dev.parent = &twl->client->dev;
	device_init_wakeup(&pdev->dev, 1);
	status = platform_device_add_data(pdev, pdata->keypad,
	sizeof(*pdata->keypad));
	if (status < 0) {
	dev_dbg(&twl->client->dev,
	"can't add keypad data, %d\n",
	status);
	platform_device_put(pdev);
	goto err;
	}
	status = platform_device_add(pdev);
	if (status < 0) {
	platform_device_put(pdev);
	dev_dbg(&twl->client->dev,
	"can't create keypad dev, %d\n",
	status);
	goto err;
	}
	} else {
	pr_debug("%s: can't alloc keypad dev\n", DRIVER_NAME);
	status = -ENOMEM;
	goto err;
	}
	}

	if (twl_has_madc() && pdata->madc) {
	pdev = platform_device_alloc("twl4030_madc", -1);
	if (pdev) {
	twl = &twl4030_modules[2];
	pdev->dev.parent = &twl->client->dev;
	device_init_wakeup(&pdev->dev, 1);
	status = platform_device_add_data(pdev, pdata->madc,
	sizeof(*pdata->madc));
	if (status < 0) {
	platform_device_put(pdev);
	dev_dbg(&twl->client->dev,
	"can't add madc data, %d\n",
	status);
	goto err;
	}
	status = platform_device_add(pdev);
	if (status < 0) {
	platform_device_put(pdev);
	dev_dbg(&twl->client->dev,
	"can't create madc dev, %d\n",
	status);
	goto err;
	}
	} else {
	pr_debug("%s: can't alloc madc dev\n", DRIVER_NAME);
	status = -ENOMEM;
	goto err;
	}
	}

	if (twl_has_rtc()) {
	twl = &twl4030_modules[3];

	pdev = platform_device_alloc("twl4030_rtc", -1);
	if (!pdev) {
	pr_debug("%s: can't alloc rtc dev\n", DRIVER_NAME);
	status = -ENOMEM;
	} else {
	pdev->dev.parent = &twl->client->dev;
	device_init_wakeup(&pdev->dev, 1);
	}

	/*
	* REVISIT platform_data here currently might use of
	* "msecure" line ... but for now we just expect board
	* setup to tell the chip "we are secure" at all times.
	* Eventually, Linux might become more aware of such
	* HW security concerns, and "least privilege".
	*/

	/* RTC module IRQ */
	if (status == 0) {
	struct resource r = {
	.start = pdata->irq_base + 8 + 3,
	.flags = IORESOURCE_IRQ,
	};

	status = platform_device_add_resources(pdev, &r, 1);
	}

	if (status == 0)
	status = platform_device_add(pdev);

	if (status < 0) {
	platform_device_put(pdev);
	dev_dbg(&twl->client->dev,
	"can't create rtc dev, %d\n",
	status);
	goto err;
	}
	}

	if (twl_has_usb() && pdata->usb) {
	twl = &twl4030_modules[0];

	pdev = platform_device_alloc("twl4030_usb", -1);
	if (!pdev) {
	pr_debug("%s: can't alloc usb dev\n", DRIVER_NAME);
	status = -ENOMEM;
	goto err;
	}

	if (status == 0) {
	pdev->dev.parent = &twl->client->dev;
	device_init_wakeup(&pdev->dev, 1);
	status = platform_device_add_data(pdev, pdata->usb,
	sizeof(*pdata->usb));
	if (status < 0) {
	platform_device_put(pdev);
	dev_dbg(&twl->client->dev,
	"can't add usb data, %d\n",
	status);
	goto err;
	}
	}

	if (status == 0) {
	struct resource r = {
	.start = pdata->irq_base + 8 + 2,
	.flags = IORESOURCE_IRQ,
	};

	status = platform_device_add_resources(pdev, &r, 1);
	}

	if (status == 0)
	status = platform_device_add(pdev);

	if (status < 0) {
	platform_device_put(pdev);
	dev_dbg(&twl->client->dev,
	"can't create usb dev, %d\n",
	status);
	}
	}

	err:
	if (status)
	pr_err("failed to add twl4030's children (status %d)\n", status);
	return status;
	}

	/----------------------------------------------------------------------/

	/*
	* These three functions initialize the on-chip clock framework,
	* letting it generate the right frequencies for USB, MADC, and
	* other purposes.
	*/
	static inline int __init protect_pm_master(void)
	{
	int e = 0;

	e = twl4030_i2c_write_u8(TWL4030_MODULE_PM_MASTER, KEY_LOCK,
	R_PROTECT_KEY);
	return e;
	}

	static inline int __init unprotect_pm_master(void)
	{
	int e = 0;

	e \|= twl4030_i2c_write_u8(TWL4030_MODULE_PM_MASTER, KEY_UNLOCK1,
	R_PROTECT_KEY);
	e \|= twl4030_i2c_write_u8(TWL4030_MODULE_PM_MASTER, KEY_UNLOCK2,
	R_PROTECT_KEY);
	return e;
	}

	static void __init clocks_init(void)
	{
	int e = 0;
	struct clk *osc;
	u32 rate;
	u8 ctrl = HFCLK_FREQ_26_MHZ;

	#if defined(CONFIG_ARCH_OMAP2) \|\| defined(CONFIG_ARCH_OMAP3)
	if (cpu_is_omap2430())
	osc = clk_get(NULL, "osc_ck");
	else
	osc = clk_get(NULL, "osc_sys_ck");
	#else
	/* REVISIT for non-OMAP systems, pass the clock rate from
	* board init code, using platform_data.
	*/
	osc = ERR_PTR(-EIO);
	#endif
	if (IS_ERR(osc)) {
	printk(KERN_WARNING "Skipping twl4030 internal clock init and "
	"using bootloader value (unknown osc rate)\n");
	return;
	}

	rate = clk_get_rate(osc);
	clk_put(osc);

	switch (rate) {
	case 19200000:
	ctrl = HFCLK_FREQ_19p2_MHZ;
	break;
	case 26000000:
	ctrl = HFCLK_FREQ_26_MHZ;
	break;
	case 38400000:
	ctrl = HFCLK_FREQ_38p4_MHZ;
	break;
	}

	ctrl \|= HIGH_PERF_SQ;
	e \|= unprotect_pm_master();
	/* effect->MADC+USB ck en */
	e \|= twl4030_i2c_write_u8(TWL4030_MODULE_PM_MASTER, ctrl, R_CFG_BOOT);
	e \|= protect_pm_master();

	if (e < 0)
	pr_err("%s: clock init err [%d]\n", DRIVER_NAME, e);
	}

	/----------------------------------------------------------------------/

	int twl_init_irq(int irq_num, unsigned irq_base, unsigned irq_end);
	int twl_exit_irq(void);

	static int twl4030_remove(struct i2c_client *client)
	{
	unsigned i;
	int status;

	status = twl_exit_irq();
	if (status < 0)
	return status;

	for (i = 0; i < TWL4030_NUM_SLAVES; i++) {
	struct twl4030_client *twl = &twl4030_modules[i];

	if (twl->client && twl->client != client)
	i2c_unregister_device(twl->client);
	twl4030_modules[i].client = NULL;
	}
	inuse = false;
	return 0;
	}

	/* NOTE: this driver only handles a single twl4030/tps659x0 chip */
	static int
	twl4030_probe(struct i2c_client client, const struct i2c_device_id id)
	{
	int status;
	unsigned i;
	struct twl4030_platform_data *pdata = client->dev.platform_data;

	if (!pdata) {
	dev_dbg(&client->dev, "no platform data?\n");
	return -EINVAL;
	}

	if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C) == 0) {
	dev_dbg(&client->dev, "can't talk I2C?\n");
	return -EIO;
	}

	if (inuse) {
	dev_dbg(&client->dev, "driver is already in use\n");
	return -EBUSY;
	}

	for (i = 0; i < TWL4030_NUM_SLAVES; i++) {
	struct twl4030_client *twl = &twl4030_modules[i];

	twl->address = client->addr + i;
	if (i == 0)
	twl->client = client;
	else {
	twl->client = i2c_new_dummy(client->adapter,
	twl->address);
	if (!twl->client) {
	dev_err(&twl->client->dev,
	"can't attach client %d\n", i);
	status = -ENOMEM;
	goto fail;
	}
	strlcpy(twl->client->name, id->name,
	sizeof(twl->client->name));
	}
	mutex_init(&twl->xfer_lock);
	}
	inuse = true;

	/* setup clock framework */
	clocks_init();

	/* Maybe init the T2 Interrupt subsystem */
	if (client->irq
	&& pdata->irq_base
	&& pdata->irq_end > pdata->irq_base) {
	status = twl_init_irq(client->irq, pdata->irq_base, pdata->irq_end);
	if (status < 0)
	goto fail;
	}

	status = add_children(pdata);
	fail:
	if (status < 0)
	twl4030_remove(client);
	return status;
	}

	static const struct i2c_device_id twl4030_ids[] = {
	{ "twl4030", 0 }, /* "Triton 2" */
	{ "tps65950", 0 }, /* catalog version of twl4030 */
	{ "tps65930", 0 }, /* fewer LDOs and DACs; no charger */
	{ "tps65920", 0 }, /* fewer LDOs; no codec or charger */
	{ "twl5030", 0 }, /* T2 updated */
	{ /* end of list */ },
	};
	MODULE_DEVICE_TABLE(i2c, twl4030_ids);

	/* One Client Driver , 4 Clients */
	static struct i2c_driver twl4030_driver = {
	.driver.name = DRIVER_NAME,
	.id_table = twl4030_ids,
	.probe = twl4030_probe,
	.remove = twl4030_remove,
	};

	static int __init twl4030_init(void)
	{
	return i2c_add_driver(&twl4030_driver);
	}
	subsys_initcall(twl4030_init);

	static void __exit twl4030_exit(void)
	{
	i2c_del_driver(&twl4030_driver);
	}
	module_exit(twl4030_exit);

	MODULE_AUTHOR("Texas Instruments, Inc.");
	MODULE_DESCRIPTION("I2C Core interface for TWL4030");
	MODULE_LICENSE("GPL");