mfd: Add initial WM8994 support
The WM8994 is a highly integrated ultra low power audio hub CODEC.
Since it includes on-board regulators and GPIOs it is represented
as a multi-function device, though the overwhelming majority of
the functionality is provided by the ASoC CODEC driver.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/wm8994-core.c b/drivers/mfd/wm8994-core.c
new file mode 100644
index 0000000..299c1af
--- /dev/null
+++ b/drivers/mfd/wm8994-core.c
@@ -0,0 +1,537 @@
+/*
+ * wm8994-core.c -- Device access for Wolfson WM8994
+ *
+ * Copyright 2009 Wolfson Microelectronics PLC.
+ *
+ * Author: Mark Brown <broonie@opensource.wolfsonmicro.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.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/mfd/core.h>
+#include <linux/regulator/consumer.h>
+#include <linux/regulator/machine.h>
+
+#include <linux/mfd/wm8994/core.h>
+#include <linux/mfd/wm8994/pdata.h>
+#include <linux/mfd/wm8994/registers.h>
+
+static int wm8994_read(struct wm8994 *wm8994, unsigned short reg,
+ int bytes, void *dest)
+{
+ int ret, i;
+ u16 *buf = dest;
+
+ BUG_ON(bytes % 2);
+ BUG_ON(bytes <= 0);
+
+ ret = wm8994->read_dev(wm8994, reg, bytes, dest);
+ if (ret < 0)
+ return ret;
+
+ for (i = 0; i < bytes / 2; i++) {
+ buf[i] = be16_to_cpu(buf[i]);
+
+ dev_vdbg(wm8994->dev, "Read %04x from R%d(0x%x)\n",
+ buf[i], reg + i, reg + i);
+ }
+
+ return 0;
+}
+
+/**
+ * wm8994_reg_read: Read a single WM8994 register.
+ *
+ * @wm8994: Device to read from.
+ * @reg: Register to read.
+ */
+int wm8994_reg_read(struct wm8994 *wm8994, unsigned short reg)
+{
+ unsigned short val;
+ int ret;
+
+ mutex_lock(&wm8994->io_lock);
+
+ ret = wm8994_read(wm8994, reg, 2, &val);
+
+ mutex_unlock(&wm8994->io_lock);
+
+ if (ret < 0)
+ return ret;
+ else
+ return val;
+}
+EXPORT_SYMBOL_GPL(wm8994_reg_read);
+
+/**
+ * wm8994_bulk_read: Read multiple WM8994 registers
+ *
+ * @wm8994: Device to read from
+ * @reg: First register
+ * @count: Number of registers
+ * @buf: Buffer to fill.
+ */
+int wm8994_bulk_read(struct wm8994 *wm8994, unsigned short reg,
+ int count, u16 *buf)
+{
+ int ret;
+
+ mutex_lock(&wm8994->io_lock);
+
+ ret = wm8994_read(wm8994, reg, count * 2, buf);
+
+ mutex_unlock(&wm8994->io_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(wm8994_bulk_read);
+
+static int wm8994_write(struct wm8994 *wm8994, unsigned short reg,
+ int bytes, void *src)
+{
+ u16 *buf = src;
+ int i;
+
+ BUG_ON(bytes % 2);
+ BUG_ON(bytes <= 0);
+
+ for (i = 0; i < bytes / 2; i++) {
+ dev_vdbg(wm8994->dev, "Write %04x to R%d(0x%x)\n",
+ buf[i], reg + i, reg + i);
+
+ buf[i] = cpu_to_be16(buf[i]);
+ }
+
+ return wm8994->write_dev(wm8994, reg, bytes, src);
+}
+
+/**
+ * wm8994_reg_write: Write a single WM8994 register.
+ *
+ * @wm8994: Device to write to.
+ * @reg: Register to write to.
+ * @val: Value to write.
+ */
+int wm8994_reg_write(struct wm8994 *wm8994, unsigned short reg,
+ unsigned short val)
+{
+ int ret;
+
+ mutex_lock(&wm8994->io_lock);
+
+ ret = wm8994_write(wm8994, reg, 2, &val);
+
+ mutex_unlock(&wm8994->io_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(wm8994_reg_write);
+
+/**
+ * wm8994_set_bits: Set the value of a bitfield in a WM8994 register
+ *
+ * @wm8994: Device to write to.
+ * @reg: Register to write to.
+ * @mask: Mask of bits to set.
+ * @val: Value to set (unshifted)
+ */
+int wm8994_set_bits(struct wm8994 *wm8994, unsigned short reg,
+ unsigned short mask, unsigned short val)
+{
+ int ret;
+ u16 r;
+
+ mutex_lock(&wm8994->io_lock);
+
+ ret = wm8994_read(wm8994, reg, 2, &r);
+ if (ret < 0)
+ goto out;
+
+ r &= ~mask;
+ r |= val;
+
+ ret = wm8994_write(wm8994, reg, 2, &r);
+
+out:
+ mutex_unlock(&wm8994->io_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(wm8994_set_bits);
+
+static struct mfd_cell wm8994_regulator_devs[] = {
+ { .name = "wm8994-ldo", .id = 1 },
+ { .name = "wm8994-ldo", .id = 2 },
+};
+
+static struct mfd_cell wm8994_devs[] = {
+ { .name = "wm8994-codec" },
+ { .name = "wm8994-gpio" },
+};
+
+/*
+ * Supplies for the main bulk of CODEC; the LDO supplies are ignored
+ * and should be handled via the standard regulator API supply
+ * management.
+ */
+static const char *wm8994_main_supplies[] = {
+ "DBVDD",
+ "DCVDD",
+ "AVDD1",
+ "AVDD2",
+ "CPVDD",
+ "SPKVDD1",
+ "SPKVDD2",
+};
+
+#ifdef CONFIG_PM
+static int wm8994_device_suspend(struct device *dev)
+{
+ struct wm8994 *wm8994 = dev_get_drvdata(dev);
+ int ret;
+
+ /* GPIO configuration state is saved here since we may be configuring
+ * the GPIO alternate functions even if we're not using the gpiolib
+ * driver for them.
+ */
+ ret = wm8994_read(wm8994, WM8994_GPIO_1, WM8994_NUM_GPIO_REGS * 2,
+ &wm8994->gpio_regs);
+ if (ret < 0)
+ dev_err(dev, "Failed to save GPIO registers: %d\n", ret);
+
+ /* For similar reasons we also stash the regulator states */
+ ret = wm8994_read(wm8994, WM8994_LDO_1, WM8994_NUM_LDO_REGS * 2,
+ &wm8994->ldo_regs);
+ if (ret < 0)
+ dev_err(dev, "Failed to save LDO registers: %d\n", ret);
+
+ ret = regulator_bulk_disable(ARRAY_SIZE(wm8994_main_supplies),
+ wm8994->supplies);
+ if (ret != 0) {
+ dev_err(dev, "Failed to disable supplies: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int wm8994_device_resume(struct device *dev)
+{
+ struct wm8994 *wm8994 = dev_get_drvdata(dev);
+ int ret;
+
+ ret = regulator_bulk_enable(ARRAY_SIZE(wm8994_main_supplies),
+ wm8994->supplies);
+ if (ret != 0) {
+ dev_err(dev, "Failed to enable supplies: %d\n", ret);
+ return ret;
+ }
+
+ ret = wm8994_write(wm8994, WM8994_LDO_1, WM8994_NUM_LDO_REGS * 2,
+ &wm8994->ldo_regs);
+ if (ret < 0)
+ dev_err(dev, "Failed to restore LDO registers: %d\n", ret);
+
+ ret = wm8994_write(wm8994, WM8994_GPIO_1, WM8994_NUM_GPIO_REGS * 2,
+ &wm8994->gpio_regs);
+ if (ret < 0)
+ dev_err(dev, "Failed to restore GPIO registers: %d\n", ret);
+
+ return 0;
+}
+#endif
+
+#ifdef CONFIG_REGULATOR
+static int wm8994_ldo_in_use(struct wm8994_pdata *pdata, int ldo)
+{
+ struct wm8994_ldo_pdata *ldo_pdata;
+
+ if (!pdata)
+ return 0;
+
+ ldo_pdata = &pdata->ldo[ldo];
+
+ if (!ldo_pdata->init_data)
+ return 0;
+
+ return ldo_pdata->init_data->num_consumer_supplies != 0;
+}
+#else
+static int wm8994_ldo_in_use(struct wm8994_pdata *pdata, int ldo)
+{
+ return 0;
+}
+#endif
+
+/*
+ * Instantiate the generic non-control parts of the device.
+ */
+static int wm8994_device_init(struct wm8994 *wm8994, unsigned long id, int irq)
+{
+ struct wm8994_pdata *pdata = wm8994->dev->platform_data;
+ int ret, i;
+
+ mutex_init(&wm8994->io_lock);
+ dev_set_drvdata(wm8994->dev, wm8994);
+
+ /* Add the on-chip regulators first for bootstrapping */
+ ret = mfd_add_devices(wm8994->dev, -1,
+ wm8994_regulator_devs,
+ ARRAY_SIZE(wm8994_regulator_devs),
+ NULL, 0);
+ if (ret != 0) {
+ dev_err(wm8994->dev, "Failed to add children: %d\n", ret);
+ goto err;
+ }
+
+ wm8994->supplies = kzalloc(sizeof(struct regulator_bulk_data) *
+ ARRAY_SIZE(wm8994_main_supplies),
+ GFP_KERNEL);
+ if (!wm8994->supplies)
+ goto err;
+
+ for (i = 0; i < ARRAY_SIZE(wm8994_main_supplies); i++)
+ wm8994->supplies[i].supply = wm8994_main_supplies[i];
+
+ ret = regulator_bulk_get(wm8994->dev, ARRAY_SIZE(wm8994_main_supplies),
+ wm8994->supplies);
+ if (ret != 0) {
+ dev_err(wm8994->dev, "Failed to get supplies: %d\n", ret);
+ goto err_get;
+ }
+
+ ret = regulator_bulk_enable(ARRAY_SIZE(wm8994_main_supplies),
+ wm8994->supplies);
+ if (ret != 0) {
+ dev_err(wm8994->dev, "Failed to enable supplies: %d\n", ret);
+ goto err_supplies;
+ }
+
+ ret = wm8994_reg_read(wm8994, WM8994_SOFTWARE_RESET);
+ if (ret < 0) {
+ dev_err(wm8994->dev, "Failed to read ID register\n");
+ goto err_enable;
+ }
+ if (ret != 0x8994) {
+ dev_err(wm8994->dev, "Device is not a WM8994, ID is %x\n",
+ ret);
+ ret = -EINVAL;
+ goto err_enable;
+ }
+
+ ret = wm8994_reg_read(wm8994, WM8994_CHIP_REVISION);
+ if (ret < 0) {
+ dev_err(wm8994->dev, "Failed to read revision register: %d\n",
+ ret);
+ goto err_enable;
+ }
+
+ switch (ret) {
+ case 0:
+ case 1:
+ dev_warn(wm8994->dev, "revision %c not fully supported\n",
+ 'A' + ret);
+ break;
+ default:
+ dev_info(wm8994->dev, "revision %c\n", 'A' + ret);
+ break;
+ }
+
+
+ if (pdata) {
+ wm8994->gpio_base = pdata->gpio_base;
+
+ /* GPIO configuration is only applied if it's non-zero */
+ for (i = 0; i < ARRAY_SIZE(pdata->gpio_defaults); i++) {
+ if (pdata->gpio_defaults[i]) {
+ wm8994_set_bits(wm8994, WM8994_GPIO_1 + i,
+ 0xffff,
+ pdata->gpio_defaults[i]);
+ }
+ }
+ }
+
+ /* In some system designs where the regulators are not in use,
+ * we can achieve a small reduction in leakage currents by
+ * floating LDO outputs. This bit makes no difference if the
+ * LDOs are enabled, it only affects cases where the LDOs were
+ * in operation and are then disabled.
+ */
+ for (i = 0; i < WM8994_NUM_LDO_REGS; i++) {
+ if (wm8994_ldo_in_use(pdata, i))
+ wm8994_set_bits(wm8994, WM8994_LDO_1 + i,
+ WM8994_LDO1_DISCH, WM8994_LDO1_DISCH);
+ else
+ wm8994_set_bits(wm8994, WM8994_LDO_1 + i,
+ WM8994_LDO1_DISCH, 0);
+ }
+
+ ret = mfd_add_devices(wm8994->dev, -1,
+ wm8994_devs, ARRAY_SIZE(wm8994_devs),
+ NULL, 0);
+ if (ret != 0) {
+ dev_err(wm8994->dev, "Failed to add children: %d\n", ret);
+ goto err_enable;
+ }
+
+ return 0;
+
+err_enable:
+ regulator_bulk_disable(ARRAY_SIZE(wm8994_main_supplies),
+ wm8994->supplies);
+err_get:
+ regulator_bulk_free(ARRAY_SIZE(wm8994_main_supplies), wm8994->supplies);
+err_supplies:
+ kfree(wm8994->supplies);
+err:
+ mfd_remove_devices(wm8994->dev);
+ kfree(wm8994);
+ return ret;
+}
+
+static void wm8994_device_exit(struct wm8994 *wm8994)
+{
+ mfd_remove_devices(wm8994->dev);
+ regulator_bulk_disable(ARRAY_SIZE(wm8994_main_supplies),
+ wm8994->supplies);
+ regulator_bulk_free(ARRAY_SIZE(wm8994_main_supplies), wm8994->supplies);
+ kfree(wm8994->supplies);
+ kfree(wm8994);
+}
+
+static int wm8994_i2c_read_device(struct wm8994 *wm8994, unsigned short reg,
+ int bytes, void *dest)
+{
+ struct i2c_client *i2c = wm8994->control_data;
+ int ret;
+ u16 r = cpu_to_be16(reg);
+
+ ret = i2c_master_send(i2c, (unsigned char *)&r, 2);
+ if (ret < 0)
+ return ret;
+ if (ret != 2)
+ return -EIO;
+
+ ret = i2c_master_recv(i2c, dest, bytes);
+ if (ret < 0)
+ return ret;
+ if (ret != bytes)
+ return -EIO;
+ return 0;
+}
+
+/* Currently we allocate the write buffer on the stack; this is OK for
+ * small writes - if we need to do large writes this will need to be
+ * revised.
+ */
+static int wm8994_i2c_write_device(struct wm8994 *wm8994, unsigned short reg,
+ int bytes, void *src)
+{
+ struct i2c_client *i2c = wm8994->control_data;
+ unsigned char msg[bytes + 2];
+ int ret;
+
+ reg = cpu_to_be16(reg);
+ memcpy(&msg[0], ®, 2);
+ memcpy(&msg[2], src, bytes);
+
+ ret = i2c_master_send(i2c, msg, bytes + 2);
+ if (ret < 0)
+ return ret;
+ if (ret < bytes + 2)
+ return -EIO;
+
+ return 0;
+}
+
+static int wm8994_i2c_probe(struct i2c_client *i2c,
+ const struct i2c_device_id *id)
+{
+ struct wm8994 *wm8994;
+
+ wm8994 = kzalloc(sizeof(struct wm8994), GFP_KERNEL);
+ if (wm8994 == NULL) {
+ kfree(i2c);
+ return -ENOMEM;
+ }
+
+ i2c_set_clientdata(i2c, wm8994);
+ wm8994->dev = &i2c->dev;
+ wm8994->control_data = i2c;
+ wm8994->read_dev = wm8994_i2c_read_device;
+ wm8994->write_dev = wm8994_i2c_write_device;
+
+ return wm8994_device_init(wm8994, id->driver_data, i2c->irq);
+}
+
+static int wm8994_i2c_remove(struct i2c_client *i2c)
+{
+ struct wm8994 *wm8994 = i2c_get_clientdata(i2c);
+
+ wm8994_device_exit(wm8994);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int wm8994_i2c_suspend(struct i2c_client *i2c, pm_message_t state)
+{
+ return wm8994_device_suspend(&i2c->dev);
+}
+
+static int wm8994_i2c_resume(struct i2c_client *i2c)
+{
+ return wm8994_device_resume(&i2c->dev);
+}
+#else
+#define wm8994_i2c_suspend NULL
+#define wm8994_i2c_resume NULL
+#endif
+
+static const struct i2c_device_id wm8994_i2c_id[] = {
+ { "wm8994", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, wm8994_i2c_id);
+
+static struct i2c_driver wm8994_i2c_driver = {
+ .driver = {
+ .name = "wm8994",
+ .owner = THIS_MODULE,
+ },
+ .probe = wm8994_i2c_probe,
+ .remove = wm8994_i2c_remove,
+ .suspend = wm8994_i2c_suspend,
+ .resume = wm8994_i2c_resume,
+ .id_table = wm8994_i2c_id,
+};
+
+static int __init wm8994_i2c_init(void)
+{
+ int ret;
+
+ ret = i2c_add_driver(&wm8994_i2c_driver);
+ if (ret != 0)
+ pr_err("Failed to register wm8994 I2C driver: %d\n", ret);
+
+ return ret;
+}
+module_init(wm8994_i2c_init);
+
+static void __exit wm8994_i2c_exit(void)
+{
+ i2c_del_driver(&wm8994_i2c_driver);
+}
+module_exit(wm8994_i2c_exit);
+
+MODULE_DESCRIPTION("Core support for the WM8994 audio CODEC");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");