mfd: TWL4030 core driver

[mirror_ubuntu-bionic-kernel.git] / drivers / mfd / twl4030-core.c

/*
 * 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/kernel_stat.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/random.h>
#include <linux/kthread.h>
#include <linux/platform_device.h>
#include <linux/clk.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

static inline void activate_irq(int irq)
{
#ifdef CONFIG_ARM
	/* ARM requires an extra step to clear IRQ_NOREQUEST, which it
	 * sets on behalf of every irq_chip.  Also sets IRQ_NOPROBE.
	 */
	set_irq_flags(irq, IRQF_VALID);
#else
	/* same effect on other architectures */
	set_irq_noprobe(irq);
#endif
}

/* Primary Interrupt Handler on TWL4030 Registers */

/* Register Definitions */

#define REG_PIH_ISR_P1			(0x1)
#define REG_PIH_ISR_P2			(0x2)
#define REG_PIH_SIR			(0x3)

/* 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)


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

/**
 * struct twl4030_mod_iregs - TWL module IMR/ISR regs to mask/clear at init
 * @mod_no: TWL4030 module number (e.g., TWL4030_MODULE_GPIO)
 * @sih_ctrl: address of module SIH_CTRL register
 * @reg_cnt: number of IMR/ISR regs
 * @imrs: pointer to array of TWL module interrupt mask register indices
 * @isrs: pointer to array of TWL module interrupt status register indices
 *
 * Ties together TWL4030 modules and lists of IMR/ISR registers to mask/clear
 * during twl_init_irq().
 */
struct twl4030_mod_iregs {
	const u8 mod_no;
	const u8 sih_ctrl;
	const u8 reg_cnt;
	const u8 *imrs;
	const u8 *isrs;
};

/* TWL4030 INT module interrupt mask registers */
static const u8 __initconst twl4030_int_imr_regs[] = {
	TWL4030_INT_PWR_IMR1,
	TWL4030_INT_PWR_IMR2,
};

/* TWL4030 INT module interrupt status registers */
static const u8 __initconst twl4030_int_isr_regs[] = {
	TWL4030_INT_PWR_ISR1,
	TWL4030_INT_PWR_ISR2,
};

/* TWL4030 INTERRUPTS module interrupt mask registers */
static const u8 __initconst twl4030_interrupts_imr_regs[] = {
	TWL4030_INTERRUPTS_BCIIMR1A,
	TWL4030_INTERRUPTS_BCIIMR1B,
	TWL4030_INTERRUPTS_BCIIMR2A,
	TWL4030_INTERRUPTS_BCIIMR2B,
};

/* TWL4030 INTERRUPTS module interrupt status registers */
static const u8 __initconst twl4030_interrupts_isr_regs[] = {
	TWL4030_INTERRUPTS_BCIISR1A,
	TWL4030_INTERRUPTS_BCIISR1B,
	TWL4030_INTERRUPTS_BCIISR2A,
	TWL4030_INTERRUPTS_BCIISR2B,
};

/* TWL4030 MADC module interrupt mask registers */
static const u8 __initconst twl4030_madc_imr_regs[] = {
	TWL4030_MADC_IMR1,
	TWL4030_MADC_IMR2,
};

/* TWL4030 MADC module interrupt status registers */
static const u8 __initconst twl4030_madc_isr_regs[] = {
	TWL4030_MADC_ISR1,
	TWL4030_MADC_ISR2,
};

/* TWL4030 keypad module interrupt mask registers */
static const u8 __initconst twl4030_keypad_imr_regs[] = {
	TWL4030_KEYPAD_KEYP_IMR1,
	TWL4030_KEYPAD_KEYP_IMR2,
};

/* TWL4030 keypad module interrupt status registers */
static const u8 __initconst twl4030_keypad_isr_regs[] = {
	TWL4030_KEYPAD_KEYP_ISR1,
	TWL4030_KEYPAD_KEYP_ISR2,
};

/* TWL4030 GPIO module interrupt mask registers */
static const u8 __initconst twl4030_gpio_imr_regs[] = {
	REG_GPIO_IMR1A,
	REG_GPIO_IMR1B,
	REG_GPIO_IMR2A,
	REG_GPIO_IMR2B,
	REG_GPIO_IMR3A,
	REG_GPIO_IMR3B,
};

/* TWL4030 GPIO module interrupt status registers */
static const u8 __initconst twl4030_gpio_isr_regs[] = {
	REG_GPIO_ISR1A,
	REG_GPIO_ISR1B,
	REG_GPIO_ISR2A,
	REG_GPIO_ISR2B,
	REG_GPIO_ISR3A,
	REG_GPIO_ISR3B,
};

/* TWL4030 modules that have IMR/ISR registers that must be masked/cleared */
static const struct twl4030_mod_iregs __initconst twl4030_mod_regs[] = {
	{
		.mod_no	  = TWL4030_MODULE_INT,
		.sih_ctrl = TWL4030_INT_PWR_SIH_CTRL,
		.reg_cnt  = ARRAY_SIZE(twl4030_int_imr_regs),
		.imrs	  = twl4030_int_imr_regs,
		.isrs	  = twl4030_int_isr_regs,
	},
	{
		.mod_no	  = TWL4030_MODULE_INTERRUPTS,
		.sih_ctrl = TWL4030_INTERRUPTS_BCISIHCTRL,
		.reg_cnt  = ARRAY_SIZE(twl4030_interrupts_imr_regs),
		.imrs	  = twl4030_interrupts_imr_regs,
		.isrs	  = twl4030_interrupts_isr_regs,
	},
	{
		.mod_no	  = TWL4030_MODULE_MADC,
		.sih_ctrl = TWL4030_MADC_SIH_CTRL,
		.reg_cnt  = ARRAY_SIZE(twl4030_madc_imr_regs),
		.imrs	  = twl4030_madc_imr_regs,
		.isrs	  = twl4030_madc_isr_regs,
	},
	{
		.mod_no	  = TWL4030_MODULE_KEYPAD,
		.sih_ctrl = TWL4030_KEYPAD_KEYP_SIH_CTRL,
		.reg_cnt  = ARRAY_SIZE(twl4030_keypad_imr_regs),
		.imrs	  = twl4030_keypad_imr_regs,
		.isrs	  = twl4030_keypad_isr_regs,
	},
	{
		.mod_no	  = TWL4030_MODULE_GPIO,
		.sih_ctrl = REG_GPIO_SIH_CTRL,
		.reg_cnt  = ARRAY_SIZE(twl4030_gpio_imr_regs),
		.imrs	  = twl4030_gpio_imr_regs,
		.isrs	  = twl4030_gpio_isr_regs,
	},
};

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

/* 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 },
};

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

/*
 * TWL4030 doesn't have PIH mask, hence dummy function for mask
 * and unmask of the (eight) interrupts reported at that level ...
 * masking is only available from SIH (secondary) modules.
 */

static void twl4030_i2c_ackirq(unsigned int irq)
{
}

static void twl4030_i2c_disableint(unsigned int irq)
{
}

static void twl4030_i2c_enableint(unsigned int irq)
{
}

static struct irq_chip twl4030_irq_chip = {
	.name	= "twl4030",
	.ack	= twl4030_i2c_ackirq,
	.mask	= twl4030_i2c_disableint,
	.unmask	= twl4030_i2c_enableint,
};

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

/* 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);

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

/*
 * do_twl4030_module_irq() is the desc->handle method for each of the twl4030
 * module interrupts that doesn't chain to another irq_chip (GPIO, power, etc).
 * It executes in kernel thread context.  On entry, cpu interrupts are disabled.
 */
static void do_twl4030_module_irq(unsigned int irq, irq_desc_t *desc)
{
	struct irqaction *action;
	const unsigned int cpu = smp_processor_id();

	/*
	 * Earlier this was desc->triggered = 1;
	 */
	desc->status |= IRQ_LEVEL;

	/*
	 * The desc->handle method would normally call the desc->chip->ack
	 * method here, but we won't bother since our ack method is NULL.
	 */

	if (!desc->depth) {
		kstat_cpu(cpu).irqs[irq]++;

		action = desc->action;
		if (action) {
			int ret;
			int status = 0;
			int retval = 0;

			local_irq_enable();

			do {
				/* Call the ISR with cpu interrupts enabled */
				ret = action->handler(irq, action->dev_id);
				if (ret == IRQ_HANDLED)
					status |= action->flags;
				retval |= ret;
				action = action->next;
			} while (action);

			if (status & IRQF_SAMPLE_RANDOM)
				add_interrupt_randomness(irq);

			local_irq_disable();

			if (retval != IRQ_HANDLED)
				printk(KERN_ERR "ISR for TWL4030 module"
					" irq %d can't handle interrupt\n",
					irq);

			/*
			 * Here is where we should call the unmask method, but
			 * again we won't bother since it is NULL.
			 */
		} else
			printk(KERN_CRIT "TWL4030 module irq %d has no ISR"
					" but can't be masked!\n", irq);
	} else
		printk(KERN_CRIT "TWL4030 module irq %d is disabled but can't"
				" be masked!\n", irq);
}

static unsigned twl4030_irq_base;

static struct completion irq_event;

/*
 * This thread processes interrupts reported by the Primary Interrupt Handler.
 */
static int twl4030_irq_thread(void *data)
{
	long irq = (long)data;
	irq_desc_t *desc = irq_desc + irq;
	static unsigned i2c_errors;
	const static unsigned max_i2c_errors = 100;

	daemonize("twl4030-irq");
	current->flags |= PF_NOFREEZE;

	while (!kthread_should_stop()) {
		int ret;
		int module_irq;
		u8 pih_isr;

		/* Wait for IRQ, then read PIH irq status (also blocking) */
		wait_for_completion_interruptible(&irq_event);

		ret = twl4030_i2c_read_u8(TWL4030_MODULE_PIH, &pih_isr,
					  REG_PIH_ISR_P1);
		if (ret) {
			pr_warning("%s: I2C error %d reading PIH ISR\n",
					DRIVER_NAME, ret);
			if (++i2c_errors >= max_i2c_errors) {
				printk(KERN_ERR "Maximum I2C error count"
						" exceeded.  Terminating %s.\n",
						__func__);
				break;
			}
			complete(&irq_event);
			continue;
		}

		/* these handlers deal with the relevant SIH irq status */
		local_irq_disable();
		for (module_irq = twl4030_irq_base;
				pih_isr;
				pih_isr >>= 1, module_irq++) {
			if (pih_isr & 0x1) {
				irq_desc_t *d = irq_desc + module_irq;

				d->handle_irq(module_irq, d);
			}
		}
		local_irq_enable();

		desc->chip->unmask(irq);
	}

	return 0;
}

/*
 * do_twl4030_irq() is the desc->handle method for the twl4030 interrupt.
 * This is a chained interrupt, so there is no desc->action method for it.
 * Now we need to query the interrupt controller in the twl4030 to determine
 * which module is generating the interrupt request.  However, we can't do i2c
 * transactions in interrupt context, so we must defer that work to a kernel
 * thread.  All we do here is acknowledge and mask the interrupt and wakeup
 * the kernel thread.
 */
static void do_twl4030_irq(unsigned int irq, irq_desc_t *desc)
{
	const unsigned int cpu = smp_processor_id();

	/*
	 * Earlier this was desc->triggered = 1;
	 */
	desc->status |= IRQ_LEVEL;

	/*
	 * Acknowledge, clear _AND_ disable the interrupt.
	 */
	desc->chip->ack(irq);

	if (!desc->depth) {
		kstat_cpu(cpu).irqs[irq]++;

		complete(&irq_event);
	}
}

static struct task_struct * __init start_twl4030_irq_thread(long irq)
{
	struct task_struct *thread;

	init_completion(&irq_event);
	thread = kthread_run(twl4030_irq_thread, (void *)irq,
			     "twl4030 irq %ld", irq);
	if (!thread)
		pr_err("%s: could not create twl4030 irq %ld thread!\n",
		       DRIVER_NAME, irq);

	return thread;
}

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

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 = TWL4030_PWRIRQ_CHG_PRES,
				.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 = {
				/* REVISIT don't hard-wire this stuff */
				.start = TWL4030_PWRIRQ_RTC,
				.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 = TWL4030_PWRIRQ_USB_PRES,
				.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);
}

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

/**
 * twl4030_i2c_clear_isr - clear TWL4030 SIH ISR regs via read + write
 * @mod_no: TWL4030 module number
 * @reg: register index to clear
 * @cor: value of the <module>_SIH_CTRL.COR bit (1 or 0)
 *
 * Either reads (cor == 1) or writes (cor == 0) to a TWL4030 interrupt
 * status register to ensure that any prior interrupts are cleared.
 * Returns the status from the I2C read operation.
 */
static int __init twl4030_i2c_clear_isr(u8 mod_no, u8 reg, u8 cor)
{
	u8 tmp;

	return (cor) ? twl4030_i2c_read_u8(mod_no, &tmp, reg) :
		twl4030_i2c_write_u8(mod_no, 0xff, reg);
}

/**
 * twl4030_read_cor_bit - are TWL module ISRs cleared by reads or writes?
 * @mod_no: TWL4030 module number
 * @reg: register index to clear
 *
 * Returns 1 if the TWL4030 SIH interrupt status registers (ISRs) for
 * the specified TWL module are cleared by reads, or 0 if cleared by
 * writes.
 */
static int twl4030_read_cor_bit(u8 mod_no, u8 reg)
{
	u8 tmp = 0;

	WARN_ON(twl4030_i2c_read_u8(mod_no, &tmp, reg) < 0);

	tmp &= TWL4030_SIH_CTRL_COR_MASK;
	tmp >>= __ffs(TWL4030_SIH_CTRL_COR_MASK);

	return tmp;
}

/**
 * twl4030_mask_clear_intrs - mask and clear all TWL4030 interrupts
 * @t: pointer to twl4030_mod_iregs array
 * @t_sz: ARRAY_SIZE(t) (starting at 1)
 *
 * Mask all TWL4030 interrupt mask registers (IMRs) and clear all
 * interrupt status registers (ISRs).  No return value, but will WARN if
 * any I2C operations fail.
 */
static void __init twl4030_mask_clear_intrs(const struct twl4030_mod_iregs *t,
					    const u8 t_sz)
{
	int i, j;

	/*
	 * N.B. - further efficiency is possible here.  Eight I2C
	 * operations on BCI and GPIO modules are avoidable if I2C
	 * burst read/write transactions were implemented.  Would
	 * probably save about 1ms of boot time and a small amount of
	 * power.
	 */
	for (i = 0; i < t_sz; i++) {
		const struct twl4030_mod_iregs tmr = t[i];
		int cor;

		/* Are ISRs cleared by reads or writes? */
		cor = twl4030_read_cor_bit(tmr.mod_no, tmr.sih_ctrl);

		for (j = 0; j < tmr.reg_cnt; j++) {

			/* Mask interrupts at the TWL4030 */
			WARN_ON(twl4030_i2c_write_u8(tmr.mod_no, 0xff,
						     tmr.imrs[j]) < 0);

			/* Clear TWL4030 ISRs */
			WARN_ON(twl4030_i2c_clear_isr(tmr.mod_no,
						      tmr.isrs[j], cor) < 0);
		}
	}
}


static void twl_init_irq(int irq_num, unsigned irq_base, unsigned irq_end)
{
	int	i;

	/*
	 * Mask and clear all TWL4030 interrupts since initially we do
	 * not have any TWL4030 module interrupt handlers present
	 */
	twl4030_mask_clear_intrs(twl4030_mod_regs,
				 ARRAY_SIZE(twl4030_mod_regs));

	twl4030_irq_base = irq_base;

	/* install an irq handler for each of the PIH modules */
	for (i = irq_base; i < irq_end; i++) {
		set_irq_chip_and_handler(i, &twl4030_irq_chip,
				do_twl4030_module_irq);
		activate_irq(i);
	}

	/* install an irq handler to demultiplex the TWL4030 interrupt */
	set_irq_data(irq_num, start_twl4030_irq_thread(irq_num));
	set_irq_chained_handler(irq_num, do_twl4030_irq);
}

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

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

	/* FIXME undo twl_init_irq() */
	if (twl4030_irq_base) {
		dev_err(&client->dev, "can't yet clean up IRQs?\n");
		return -ENOSYS;
	}

	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 || twl4030_irq_base) {
		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) {
		twl_init_irq(client->irq, pdata->irq_base, pdata->irq_end);
		dev_info(&client->dev, "IRQ %d chains IRQs %d..%d\n",
				client->irq, pdata->irq_base, pdata->irq_end - 1);
	}

	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");