![Rabin Vincent](/assets/img/avatar_default.png)
The TC35892 I/O Expander provides 24 GPIOs, a keypad controller, timers, and a rotator wheel interface. This patch adds the MFD core. Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
348 lines
7.5 KiB
C
348 lines
7.5 KiB
C
/*
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* Copyright (C) ST-Ericsson SA 2010
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*
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* License Terms: GNU General Public License, version 2
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* Author: Hanumath Prasad <hanumath.prasad@stericsson.com> for ST-Ericsson
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* Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
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*/
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/slab.h>
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#include <linux/i2c.h>
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#include <linux/mfd/core.h>
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#include <linux/mfd/tc35892.h>
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/**
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* tc35892_reg_read() - read a single TC35892 register
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* @tc35892: Device to read from
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* @reg: Register to read
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*/
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int tc35892_reg_read(struct tc35892 *tc35892, u8 reg)
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{
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int ret;
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ret = i2c_smbus_read_byte_data(tc35892->i2c, reg);
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if (ret < 0)
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dev_err(tc35892->dev, "failed to read reg %#x: %d\n",
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reg, ret);
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return ret;
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}
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EXPORT_SYMBOL_GPL(tc35892_reg_read);
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/**
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* tc35892_reg_read() - write a single TC35892 register
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* @tc35892: Device to write to
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* @reg: Register to read
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* @data: Value to write
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*/
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int tc35892_reg_write(struct tc35892 *tc35892, u8 reg, u8 data)
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{
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int ret;
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ret = i2c_smbus_write_byte_data(tc35892->i2c, reg, data);
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if (ret < 0)
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dev_err(tc35892->dev, "failed to write reg %#x: %d\n",
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reg, ret);
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return ret;
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}
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EXPORT_SYMBOL_GPL(tc35892_reg_write);
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/**
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* tc35892_block_read() - read multiple TC35892 registers
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* @tc35892: Device to read from
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* @reg: First register
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* @length: Number of registers
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* @values: Buffer to write to
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*/
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int tc35892_block_read(struct tc35892 *tc35892, u8 reg, u8 length, u8 *values)
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{
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int ret;
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ret = i2c_smbus_read_i2c_block_data(tc35892->i2c, reg, length, values);
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if (ret < 0)
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dev_err(tc35892->dev, "failed to read regs %#x: %d\n",
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reg, ret);
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return ret;
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}
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EXPORT_SYMBOL_GPL(tc35892_block_read);
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/**
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* tc35892_block_write() - write multiple TC35892 registers
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* @tc35892: Device to write to
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* @reg: First register
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* @length: Number of registers
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* @values: Values to write
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*/
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int tc35892_block_write(struct tc35892 *tc35892, u8 reg, u8 length,
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const u8 *values)
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{
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int ret;
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ret = i2c_smbus_write_i2c_block_data(tc35892->i2c, reg, length,
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values);
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if (ret < 0)
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dev_err(tc35892->dev, "failed to write regs %#x: %d\n",
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reg, ret);
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return ret;
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}
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EXPORT_SYMBOL_GPL(tc35892_block_write);
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/**
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* tc35892_set_bits() - set the value of a bitfield in a TC35892 register
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* @tc35892: Device to write to
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* @reg: Register to write
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* @mask: Mask of bits to set
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* @values: Value to set
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*/
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int tc35892_set_bits(struct tc35892 *tc35892, u8 reg, u8 mask, u8 val)
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{
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int ret;
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mutex_lock(&tc35892->lock);
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ret = tc35892_reg_read(tc35892, reg);
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if (ret < 0)
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goto out;
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ret &= ~mask;
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ret |= val;
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ret = tc35892_reg_write(tc35892, reg, ret);
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out:
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mutex_unlock(&tc35892->lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(tc35892_set_bits);
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static struct resource gpio_resources[] = {
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{
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.start = TC35892_INT_GPIIRQ,
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.end = TC35892_INT_GPIIRQ,
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.flags = IORESOURCE_IRQ,
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},
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};
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static struct mfd_cell tc35892_devs[] = {
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{
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.name = "tc35892-gpio",
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.num_resources = ARRAY_SIZE(gpio_resources),
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.resources = &gpio_resources[0],
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},
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};
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static irqreturn_t tc35892_irq(int irq, void *data)
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{
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struct tc35892 *tc35892 = data;
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int status;
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status = tc35892_reg_read(tc35892, TC35892_IRQST);
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if (status < 0)
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return IRQ_NONE;
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while (status) {
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int bit = __ffs(status);
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handle_nested_irq(tc35892->irq_base + bit);
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status &= ~(1 << bit);
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}
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/*
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* A dummy read or write (to any register) appears to be necessary to
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* have the last interrupt clear (for example, GPIO IC write) take
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* effect.
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*/
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tc35892_reg_read(tc35892, TC35892_IRQST);
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return IRQ_HANDLED;
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}
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static void tc35892_irq_dummy(unsigned int irq)
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{
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/* No mask/unmask at this level */
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}
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static struct irq_chip tc35892_irq_chip = {
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.name = "tc35892",
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.mask = tc35892_irq_dummy,
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.unmask = tc35892_irq_dummy,
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};
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static int tc35892_irq_init(struct tc35892 *tc35892)
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{
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int base = tc35892->irq_base;
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int irq;
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for (irq = base; irq < base + TC35892_NR_INTERNAL_IRQS; irq++) {
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set_irq_chip_data(irq, tc35892);
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set_irq_chip_and_handler(irq, &tc35892_irq_chip,
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handle_edge_irq);
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set_irq_nested_thread(irq, 1);
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#ifdef CONFIG_ARM
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set_irq_flags(irq, IRQF_VALID);
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#else
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set_irq_noprobe(irq);
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#endif
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}
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return 0;
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}
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static void tc35892_irq_remove(struct tc35892 *tc35892)
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{
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int base = tc35892->irq_base;
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int irq;
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for (irq = base; irq < base + TC35892_NR_INTERNAL_IRQS; irq++) {
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#ifdef CONFIG_ARM
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set_irq_flags(irq, 0);
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#endif
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set_irq_chip_and_handler(irq, NULL, NULL);
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set_irq_chip_data(irq, NULL);
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}
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}
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static int tc35892_chip_init(struct tc35892 *tc35892)
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{
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int manf, ver, ret;
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manf = tc35892_reg_read(tc35892, TC35892_MANFCODE);
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if (manf < 0)
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return manf;
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ver = tc35892_reg_read(tc35892, TC35892_VERSION);
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if (ver < 0)
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return ver;
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if (manf != TC35892_MANFCODE_MAGIC) {
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dev_err(tc35892->dev, "unknown manufacturer: %#x\n", manf);
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return -EINVAL;
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}
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dev_info(tc35892->dev, "manufacturer: %#x, version: %#x\n", manf, ver);
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/* Put everything except the IRQ module into reset */
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ret = tc35892_reg_write(tc35892, TC35892_RSTCTRL,
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TC35892_RSTCTRL_TIMRST
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| TC35892_RSTCTRL_ROTRST
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| TC35892_RSTCTRL_KBDRST
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| TC35892_RSTCTRL_GPIRST);
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if (ret < 0)
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return ret;
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/* Clear the reset interrupt. */
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return tc35892_reg_write(tc35892, TC35892_RSTINTCLR, 0x1);
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}
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static int __devinit tc35892_probe(struct i2c_client *i2c,
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const struct i2c_device_id *id)
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{
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struct tc35892_platform_data *pdata = i2c->dev.platform_data;
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struct tc35892 *tc35892;
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int ret;
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if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA
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| I2C_FUNC_SMBUS_I2C_BLOCK))
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return -EIO;
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tc35892 = kzalloc(sizeof(struct tc35892), GFP_KERNEL);
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if (!tc35892)
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return -ENOMEM;
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mutex_init(&tc35892->lock);
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tc35892->dev = &i2c->dev;
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tc35892->i2c = i2c;
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tc35892->pdata = pdata;
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tc35892->irq_base = pdata->irq_base;
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tc35892->num_gpio = id->driver_data;
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i2c_set_clientdata(i2c, tc35892);
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ret = tc35892_chip_init(tc35892);
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if (ret)
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goto out_free;
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ret = tc35892_irq_init(tc35892);
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if (ret)
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goto out_free;
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ret = request_threaded_irq(tc35892->i2c->irq, NULL, tc35892_irq,
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IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
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"tc35892", tc35892);
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if (ret) {
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dev_err(tc35892->dev, "failed to request IRQ: %d\n", ret);
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goto out_removeirq;
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}
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ret = mfd_add_devices(tc35892->dev, -1, tc35892_devs,
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ARRAY_SIZE(tc35892_devs), NULL,
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tc35892->irq_base);
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if (ret) {
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dev_err(tc35892->dev, "failed to add children\n");
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goto out_freeirq;
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}
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return 0;
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out_freeirq:
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free_irq(tc35892->i2c->irq, tc35892);
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out_removeirq:
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tc35892_irq_remove(tc35892);
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out_free:
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i2c_set_clientdata(i2c, NULL);
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kfree(tc35892);
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return ret;
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}
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static int __devexit tc35892_remove(struct i2c_client *client)
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{
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struct tc35892 *tc35892 = i2c_get_clientdata(client);
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mfd_remove_devices(tc35892->dev);
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free_irq(tc35892->i2c->irq, tc35892);
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tc35892_irq_remove(tc35892);
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i2c_set_clientdata(client, NULL);
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kfree(tc35892);
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return 0;
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}
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static const struct i2c_device_id tc35892_id[] = {
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{ "tc35892", 24 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, tc35892_id);
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static struct i2c_driver tc35892_driver = {
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.driver.name = "tc35892",
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.driver.owner = THIS_MODULE,
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.probe = tc35892_probe,
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.remove = __devexit_p(tc35892_remove),
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.id_table = tc35892_id,
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};
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static int __init tc35892_init(void)
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{
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return i2c_add_driver(&tc35892_driver);
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}
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subsys_initcall(tc35892_init);
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static void __exit tc35892_exit(void)
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{
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i2c_del_driver(&tc35892_driver);
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}
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module_exit(tc35892_exit);
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MODULE_LICENSE("GPL v2");
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MODULE_DESCRIPTION("TC35892 MFD core driver");
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MODULE_AUTHOR("Hanumath Prasad, Rabin Vincent");
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