diff options
Diffstat (limited to 'drivers/mfd/tc35892.c')
-rw-r--r-- | drivers/mfd/tc35892.c | 345 |
1 files changed, 345 insertions, 0 deletions
diff --git a/drivers/mfd/tc35892.c b/drivers/mfd/tc35892.c new file mode 100644 index 00000000000..e619e2a5599 --- /dev/null +++ b/drivers/mfd/tc35892.c @@ -0,0 +1,345 @@ +/* + * Copyright (C) ST-Ericsson SA 2010 + * + * License Terms: GNU General Public License, version 2 + * Author: Hanumath Prasad <hanumath.prasad@stericsson.com> for ST-Ericsson + * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson + */ + +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/slab.h> +#include <linux/i2c.h> +#include <linux/mfd/core.h> +#include <linux/mfd/tc35892.h> + +/** + * tc35892_reg_read() - read a single TC35892 register + * @tc35892: Device to read from + * @reg: Register to read + */ +int tc35892_reg_read(struct tc35892 *tc35892, u8 reg) +{ + int ret; + + ret = i2c_smbus_read_byte_data(tc35892->i2c, reg); + if (ret < 0) + dev_err(tc35892->dev, "failed to read reg %#x: %d\n", + reg, ret); + + return ret; +} +EXPORT_SYMBOL_GPL(tc35892_reg_read); + +/** + * tc35892_reg_read() - write a single TC35892 register + * @tc35892: Device to write to + * @reg: Register to read + * @data: Value to write + */ +int tc35892_reg_write(struct tc35892 *tc35892, u8 reg, u8 data) +{ + int ret; + + ret = i2c_smbus_write_byte_data(tc35892->i2c, reg, data); + if (ret < 0) + dev_err(tc35892->dev, "failed to write reg %#x: %d\n", + reg, ret); + + return ret; +} +EXPORT_SYMBOL_GPL(tc35892_reg_write); + +/** + * tc35892_block_read() - read multiple TC35892 registers + * @tc35892: Device to read from + * @reg: First register + * @length: Number of registers + * @values: Buffer to write to + */ +int tc35892_block_read(struct tc35892 *tc35892, u8 reg, u8 length, u8 *values) +{ + int ret; + + ret = i2c_smbus_read_i2c_block_data(tc35892->i2c, reg, length, values); + if (ret < 0) + dev_err(tc35892->dev, "failed to read regs %#x: %d\n", + reg, ret); + + return ret; +} +EXPORT_SYMBOL_GPL(tc35892_block_read); + +/** + * tc35892_block_write() - write multiple TC35892 registers + * @tc35892: Device to write to + * @reg: First register + * @length: Number of registers + * @values: Values to write + */ +int tc35892_block_write(struct tc35892 *tc35892, u8 reg, u8 length, + const u8 *values) +{ + int ret; + + ret = i2c_smbus_write_i2c_block_data(tc35892->i2c, reg, length, + values); + if (ret < 0) + dev_err(tc35892->dev, "failed to write regs %#x: %d\n", + reg, ret); + + return ret; +} +EXPORT_SYMBOL_GPL(tc35892_block_write); + +/** + * tc35892_set_bits() - set the value of a bitfield in a TC35892 register + * @tc35892: Device to write to + * @reg: Register to write + * @mask: Mask of bits to set + * @values: Value to set + */ +int tc35892_set_bits(struct tc35892 *tc35892, u8 reg, u8 mask, u8 val) +{ + int ret; + + mutex_lock(&tc35892->lock); + + ret = tc35892_reg_read(tc35892, reg); + if (ret < 0) + goto out; + + ret &= ~mask; + ret |= val; + + ret = tc35892_reg_write(tc35892, reg, ret); + +out: + mutex_unlock(&tc35892->lock); + return ret; +} +EXPORT_SYMBOL_GPL(tc35892_set_bits); + +static struct resource gpio_resources[] = { + { + .start = TC35892_INT_GPIIRQ, + .end = TC35892_INT_GPIIRQ, + .flags = IORESOURCE_IRQ, + }, +}; + +static struct mfd_cell tc35892_devs[] = { + { + .name = "tc35892-gpio", + .num_resources = ARRAY_SIZE(gpio_resources), + .resources = &gpio_resources[0], + }, +}; + +static irqreturn_t tc35892_irq(int irq, void *data) +{ + struct tc35892 *tc35892 = data; + int status; + + status = tc35892_reg_read(tc35892, TC35892_IRQST); + if (status < 0) + return IRQ_NONE; + + while (status) { + int bit = __ffs(status); + + handle_nested_irq(tc35892->irq_base + bit); + status &= ~(1 << bit); + } + + /* + * A dummy read or write (to any register) appears to be necessary to + * have the last interrupt clear (for example, GPIO IC write) take + * effect. + */ + tc35892_reg_read(tc35892, TC35892_IRQST); + + return IRQ_HANDLED; +} + +static void tc35892_irq_dummy(unsigned int irq) +{ + /* No mask/unmask at this level */ +} + +static struct irq_chip tc35892_irq_chip = { + .name = "tc35892", + .mask = tc35892_irq_dummy, + .unmask = tc35892_irq_dummy, +}; + +static int tc35892_irq_init(struct tc35892 *tc35892) +{ + int base = tc35892->irq_base; + int irq; + + for (irq = base; irq < base + TC35892_NR_INTERNAL_IRQS; irq++) { + set_irq_chip_data(irq, tc35892); + set_irq_chip_and_handler(irq, &tc35892_irq_chip, + handle_edge_irq); + set_irq_nested_thread(irq, 1); +#ifdef CONFIG_ARM + set_irq_flags(irq, IRQF_VALID); +#else + set_irq_noprobe(irq); +#endif + } + + return 0; +} + +static void tc35892_irq_remove(struct tc35892 *tc35892) +{ + int base = tc35892->irq_base; + int irq; + + for (irq = base; irq < base + TC35892_NR_INTERNAL_IRQS; irq++) { +#ifdef CONFIG_ARM + set_irq_flags(irq, 0); +#endif + set_irq_chip_and_handler(irq, NULL, NULL); + set_irq_chip_data(irq, NULL); + } +} + +static int tc35892_chip_init(struct tc35892 *tc35892) +{ + int manf, ver, ret; + + manf = tc35892_reg_read(tc35892, TC35892_MANFCODE); + if (manf < 0) + return manf; + + ver = tc35892_reg_read(tc35892, TC35892_VERSION); + if (ver < 0) + return ver; + + if (manf != TC35892_MANFCODE_MAGIC) { + dev_err(tc35892->dev, "unknown manufacturer: %#x\n", manf); + return -EINVAL; + } + + dev_info(tc35892->dev, "manufacturer: %#x, version: %#x\n", manf, ver); + + /* Put everything except the IRQ module into reset */ + ret = tc35892_reg_write(tc35892, TC35892_RSTCTRL, + TC35892_RSTCTRL_TIMRST + | TC35892_RSTCTRL_ROTRST + | TC35892_RSTCTRL_KBDRST + | TC35892_RSTCTRL_GPIRST); + if (ret < 0) + return ret; + + /* Clear the reset interrupt. */ + return tc35892_reg_write(tc35892, TC35892_RSTINTCLR, 0x1); +} + +static int __devinit tc35892_probe(struct i2c_client *i2c, + const struct i2c_device_id *id) +{ + struct tc35892_platform_data *pdata = i2c->dev.platform_data; + struct tc35892 *tc35892; + int ret; + + if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA + | I2C_FUNC_SMBUS_I2C_BLOCK)) + return -EIO; + + tc35892 = kzalloc(sizeof(struct tc35892), GFP_KERNEL); + if (!tc35892) + return -ENOMEM; + + mutex_init(&tc35892->lock); + + tc35892->dev = &i2c->dev; + tc35892->i2c = i2c; + tc35892->pdata = pdata; + tc35892->irq_base = pdata->irq_base; + tc35892->num_gpio = id->driver_data; + + i2c_set_clientdata(i2c, tc35892); + + ret = tc35892_chip_init(tc35892); + if (ret) + goto out_free; + + ret = tc35892_irq_init(tc35892); + if (ret) + goto out_free; + + ret = request_threaded_irq(tc35892->i2c->irq, NULL, tc35892_irq, + IRQF_TRIGGER_FALLING | IRQF_ONESHOT, + "tc35892", tc35892); + if (ret) { + dev_err(tc35892->dev, "failed to request IRQ: %d\n", ret); + goto out_removeirq; + } + + ret = mfd_add_devices(tc35892->dev, -1, tc35892_devs, + ARRAY_SIZE(tc35892_devs), NULL, + tc35892->irq_base); + if (ret) { + dev_err(tc35892->dev, "failed to add children\n"); + goto out_freeirq; + } + + return 0; + +out_freeirq: + free_irq(tc35892->i2c->irq, tc35892); +out_removeirq: + tc35892_irq_remove(tc35892); +out_free: + kfree(tc35892); + return ret; +} + +static int __devexit tc35892_remove(struct i2c_client *client) +{ + struct tc35892 *tc35892 = i2c_get_clientdata(client); + + mfd_remove_devices(tc35892->dev); + + free_irq(tc35892->i2c->irq, tc35892); + tc35892_irq_remove(tc35892); + + kfree(tc35892); + + return 0; +} + +static const struct i2c_device_id tc35892_id[] = { + { "tc35892", 24 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, tc35892_id); + +static struct i2c_driver tc35892_driver = { + .driver.name = "tc35892", + .driver.owner = THIS_MODULE, + .probe = tc35892_probe, + .remove = __devexit_p(tc35892_remove), + .id_table = tc35892_id, +}; + +static int __init tc35892_init(void) +{ + return i2c_add_driver(&tc35892_driver); +} +subsys_initcall(tc35892_init); + +static void __exit tc35892_exit(void) +{ + i2c_del_driver(&tc35892_driver); +} +module_exit(tc35892_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("TC35892 MFD core driver"); +MODULE_AUTHOR("Hanumath Prasad, Rabin Vincent"); |