diff options
Diffstat (limited to 'drivers/mfd/wm8400-core.c')
| -rw-r--r-- | drivers/mfd/wm8400-core.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/drivers/mfd/wm8400-core.c b/drivers/mfd/wm8400-core.c new file mode 100644 index 000000000..75483c9be --- /dev/null +++ b/drivers/mfd/wm8400-core.c @@ -0,0 +1,163 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Core driver for WM8400. + * + * Copyright 2008 Wolfson Microelectronics PLC. + * + * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> + */ + +#include <linux/init.h> +#include <linux/bug.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/kernel.h> +#include <linux/mfd/core.h> +#include <linux/mfd/wm8400-private.h> +#include <linux/mfd/wm8400-audio.h> +#include <linux/regmap.h> +#include <linux/slab.h> + +static bool wm8400_volatile(struct device *dev, unsigned int reg) +{ + switch (reg) { + case WM8400_INTERRUPT_STATUS_1: + case WM8400_INTERRUPT_LEVELS: + case WM8400_SHUTDOWN_REASON: + return true; + default: + return false; + } +} + +static int wm8400_register_codec(struct wm8400 *wm8400) +{ + const struct mfd_cell cell = { + .name = "wm8400-codec", + .platform_data = wm8400, + .pdata_size = sizeof(*wm8400), + }; + + return devm_mfd_add_devices(wm8400->dev, -1, &cell, 1, NULL, 0, NULL); +} + +/* + * wm8400_init - Generic initialisation + * + * The WM8400 can be configured as either an I2C or SPI device. Probe + * functions for each bus set up the accessors then call into this to + * set up the device itself. + */ +static int wm8400_init(struct wm8400 *wm8400, + struct wm8400_platform_data *pdata) +{ + unsigned int reg; + int ret; + + /* Check that this is actually a WM8400 */ + ret = regmap_read(wm8400->regmap, WM8400_RESET_ID, ®); + if (ret != 0) { + dev_err(wm8400->dev, "Chip ID register read failed\n"); + return -EIO; + } + if (reg != 0x6172) { + dev_err(wm8400->dev, "Device is not a WM8400, ID is %x\n", + reg); + return -ENODEV; + } + + ret = regmap_read(wm8400->regmap, WM8400_ID, ®); + if (ret != 0) { + dev_err(wm8400->dev, "ID register read failed: %d\n", ret); + return ret; + } + reg = (reg & WM8400_CHIP_REV_MASK) >> WM8400_CHIP_REV_SHIFT; + dev_info(wm8400->dev, "WM8400 revision %x\n", reg); + + ret = wm8400_register_codec(wm8400); + if (ret != 0) { + dev_err(wm8400->dev, "Failed to register codec\n"); + return ret; + } + + if (pdata && pdata->platform_init) { + ret = pdata->platform_init(wm8400->dev); + if (ret != 0) { + dev_err(wm8400->dev, "Platform init failed: %d\n", + ret); + return ret; + } + } else + dev_warn(wm8400->dev, "No platform initialisation supplied\n"); + + return 0; +} + +static const struct regmap_config wm8400_regmap_config = { + .reg_bits = 8, + .val_bits = 16, + .max_register = WM8400_REGISTER_COUNT - 1, + + .volatile_reg = wm8400_volatile, + + .cache_type = REGCACHE_RBTREE, +}; + +/** + * wm8400_reset_codec_reg_cache - Reset cached codec registers to + * their default values. + * + * @wm8400: pointer to local driver data structure + */ +void wm8400_reset_codec_reg_cache(struct wm8400 *wm8400) +{ + regmap_reinit_cache(wm8400->regmap, &wm8400_regmap_config); +} +EXPORT_SYMBOL_GPL(wm8400_reset_codec_reg_cache); + +#if IS_ENABLED(CONFIG_I2C) +static int wm8400_i2c_probe(struct i2c_client *i2c) +{ + struct wm8400 *wm8400; + + wm8400 = devm_kzalloc(&i2c->dev, sizeof(struct wm8400), GFP_KERNEL); + if (!wm8400) + return -ENOMEM; + + wm8400->regmap = devm_regmap_init_i2c(i2c, &wm8400_regmap_config); + if (IS_ERR(wm8400->regmap)) + return PTR_ERR(wm8400->regmap); + + wm8400->dev = &i2c->dev; + i2c_set_clientdata(i2c, wm8400); + + return wm8400_init(wm8400, dev_get_platdata(&i2c->dev)); +} + +static const struct i2c_device_id wm8400_i2c_id[] = { + { "wm8400", 0 }, + { } +}; + +static struct i2c_driver wm8400_i2c_driver = { + .driver = { + .name = "WM8400", + }, + .probe = wm8400_i2c_probe, + .id_table = wm8400_i2c_id, +}; +#endif + +static int __init wm8400_driver_init(void) +{ + int ret = -ENODEV; + +#if IS_ENABLED(CONFIG_I2C) + ret = i2c_add_driver(&wm8400_i2c_driver); + if (ret != 0) + pr_err("Failed to register I2C driver: %d\n", ret); +#endif + + return ret; +} +subsys_initcall(wm8400_driver_init); |