diff options
Diffstat (limited to 'drivers/mfd/retu-mfd.c')
| -rw-r--r-- | drivers/mfd/retu-mfd.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/drivers/mfd/retu-mfd.c b/drivers/mfd/retu-mfd.c new file mode 100644 index 000000000000..7ff4a37ab0c0 --- /dev/null +++ b/drivers/mfd/retu-mfd.c @@ -0,0 +1,264 @@ +/* + * Retu MFD driver + * + * Copyright (C) 2004, 2005 Nokia Corporation + * + * Based on code written by Juha Yrjölä, David Weinehall and Mikko Ylinen. + * Rewritten by Aaro Koskinen. + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file "COPYING" in the main directory of this + * archive for more details. + * + * 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. + */ + +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/irq.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/mutex.h> +#include <linux/module.h> +#include <linux/regmap.h> +#include <linux/mfd/core.h> +#include <linux/mfd/retu.h> +#include <linux/interrupt.h> +#include <linux/moduleparam.h> + +/* Registers */ +#define RETU_REG_ASICR 0x00 /* ASIC ID and revision */ +#define RETU_REG_ASICR_VILMA (1 << 7) /* Bit indicating Vilma */ +#define RETU_REG_IDR 0x01 /* Interrupt ID */ +#define RETU_REG_IMR 0x02 /* Interrupt mask */ + +/* Interrupt sources */ +#define RETU_INT_PWR 0 /* Power button */ + +struct retu_dev { + struct regmap *regmap; + struct device *dev; + struct mutex mutex; + struct regmap_irq_chip_data *irq_data; +}; + +static struct resource retu_pwrbutton_res[] = { + { + .name = "retu-pwrbutton", + .start = RETU_INT_PWR, + .end = RETU_INT_PWR, + .flags = IORESOURCE_IRQ, + }, +}; + +static struct mfd_cell retu_devs[] = { + { + .name = "retu-wdt" + }, + { + .name = "retu-pwrbutton", + .resources = retu_pwrbutton_res, + .num_resources = ARRAY_SIZE(retu_pwrbutton_res), + } +}; + +static struct regmap_irq retu_irqs[] = { + [RETU_INT_PWR] = { + .mask = 1 << RETU_INT_PWR, + } +}; + +static struct regmap_irq_chip retu_irq_chip = { + .name = "RETU", + .irqs = retu_irqs, + .num_irqs = ARRAY_SIZE(retu_irqs), + .num_regs = 1, + .status_base = RETU_REG_IDR, + .mask_base = RETU_REG_IMR, + .ack_base = RETU_REG_IDR, +}; + +/* Retu device registered for the power off. */ +static struct retu_dev *retu_pm_power_off; + +int retu_read(struct retu_dev *rdev, u8 reg) +{ + int ret; + int value; + + mutex_lock(&rdev->mutex); + ret = regmap_read(rdev->regmap, reg, &value); + mutex_unlock(&rdev->mutex); + + return ret ? ret : value; +} +EXPORT_SYMBOL_GPL(retu_read); + +int retu_write(struct retu_dev *rdev, u8 reg, u16 data) +{ + int ret; + + mutex_lock(&rdev->mutex); + ret = regmap_write(rdev->regmap, reg, data); + mutex_unlock(&rdev->mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(retu_write); + +static void retu_power_off(void) +{ + struct retu_dev *rdev = retu_pm_power_off; + int reg; + + mutex_lock(&retu_pm_power_off->mutex); + + /* Ignore power button state */ + regmap_read(rdev->regmap, RETU_REG_CC1, ®); + regmap_write(rdev->regmap, RETU_REG_CC1, reg | 2); + + /* Expire watchdog immediately */ + regmap_write(rdev->regmap, RETU_REG_WATCHDOG, 0); + + /* Wait for poweroff */ + for (;;) + cpu_relax(); + + mutex_unlock(&retu_pm_power_off->mutex); +} + +static int retu_regmap_read(void *context, const void *reg, size_t reg_size, + void *val, size_t val_size) +{ + int ret; + struct device *dev = context; + struct i2c_client *i2c = to_i2c_client(dev); + + BUG_ON(reg_size != 1 || val_size != 2); + + ret = i2c_smbus_read_word_data(i2c, *(u8 const *)reg); + if (ret < 0) + return ret; + + *(u16 *)val = ret; + return 0; +} + +static int retu_regmap_write(void *context, const void *data, size_t count) +{ + u8 reg; + u16 val; + struct device *dev = context; + struct i2c_client *i2c = to_i2c_client(dev); + + BUG_ON(count != sizeof(reg) + sizeof(val)); + memcpy(®, data, sizeof(reg)); + memcpy(&val, data + sizeof(reg), sizeof(val)); + return i2c_smbus_write_word_data(i2c, reg, val); +} + +static struct regmap_bus retu_bus = { + .read = retu_regmap_read, + .write = retu_regmap_write, + .val_format_endian_default = REGMAP_ENDIAN_NATIVE, +}; + +static struct regmap_config retu_config = { + .reg_bits = 8, + .val_bits = 16, +}; + +static int __devinit retu_probe(struct i2c_client *i2c, + const struct i2c_device_id *id) +{ + struct retu_dev *rdev; + int ret; + + rdev = devm_kzalloc(&i2c->dev, sizeof(*rdev), GFP_KERNEL); + if (rdev == NULL) + return -ENOMEM; + + i2c_set_clientdata(i2c, rdev); + rdev->dev = &i2c->dev; + mutex_init(&rdev->mutex); + rdev->regmap = devm_regmap_init(&i2c->dev, &retu_bus, &i2c->dev, + &retu_config); + if (IS_ERR(rdev->regmap)) + return PTR_ERR(rdev->regmap); + + ret = retu_read(rdev, RETU_REG_ASICR); + if (ret < 0) { + dev_err(rdev->dev, "could not read Retu revision: %d\n", ret); + return ret; + } + + dev_info(rdev->dev, "Retu%s v%d.%d found\n", + (ret & RETU_REG_ASICR_VILMA) ? " & Vilma" : "", + (ret >> 4) & 0x7, ret & 0xf); + + /* Mask all RETU interrupts. */ + ret = retu_write(rdev, RETU_REG_IMR, 0xffff); + if (ret < 0) + return ret; + + ret = regmap_add_irq_chip(rdev->regmap, i2c->irq, IRQF_ONESHOT, -1, + &retu_irq_chip, &rdev->irq_data); + if (ret < 0) + return ret; + + ret = mfd_add_devices(rdev->dev, -1, retu_devs, ARRAY_SIZE(retu_devs), + NULL, regmap_irq_chip_get_base(rdev->irq_data), + NULL); + if (ret < 0) { + regmap_del_irq_chip(i2c->irq, rdev->irq_data); + return ret; + } + + if (!pm_power_off) { + retu_pm_power_off = rdev; + pm_power_off = retu_power_off; + } + + return 0; +} + +static int __devexit retu_remove(struct i2c_client *i2c) +{ + struct retu_dev *rdev = i2c_get_clientdata(i2c); + + if (retu_pm_power_off == rdev) { + pm_power_off = NULL; + retu_pm_power_off = NULL; + } + mfd_remove_devices(rdev->dev); + regmap_del_irq_chip(i2c->irq, rdev->irq_data); + + return 0; +} + +static const struct i2c_device_id retu_id[] = { + { "retu-mfd", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, retu_id); + +static struct i2c_driver retu_driver = { + .driver = { + .name = "retu-mfd", + .owner = THIS_MODULE, + }, + .probe = retu_probe, + .remove = retu_remove, + .id_table = retu_id, +}; +module_i2c_driver(retu_driver); + +MODULE_DESCRIPTION("Retu MFD driver"); +MODULE_AUTHOR("Juha Yrjölä"); +MODULE_AUTHOR("David Weinehall"); +MODULE_AUTHOR("Mikko Ylinen"); +MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>"); +MODULE_LICENSE("GPL"); |