mfd: Core support for the WM8350 AudioPlus PMIC

The WM8350 is an integrated audio and power management subsystem
intended for use as the primary PMIC in mobile multimedia applications.
The WM8350 can be controlled via either I2C or SPI - the control
interface is provided by a separate module in order to allow greatest
flexibility in configuring the kernel.

This driver was originally written by Liam Girdwood and has since been
updated to current kernel APIs and split up for submission by me.  All
the heavy lifting here was done by Liam.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Samuel Ortiz <sameo@openedhand.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

1 files changed, 456 insertions, 0 deletions

diff --git a/drivers/mfd/wm8350-core.c b/drivers/mfd/wm8350-core.c
new file mode 100644
index 000000000000..c7552c0b7797
--- /dev/null
+++ b/drivers/mfd/wm8350-core.c
@@ -0,0 +1,456 @@
+/*
+ * wm8350-core.c  --  Device access for Wolfson WM8350
+ *
+ * Copyright 2007, 2008 Wolfson Microelectronics PLC.
+ *
+ * Author: Liam Girdwood, Mark Brown
+ *
+ *  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/init.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+
+#include <linux/mfd/wm8350/core.h>
+#include <linux/mfd/wm8350/audio.h>
+#include <linux/mfd/wm8350/gpio.h>
+#include <linux/mfd/wm8350/pmic.h>
+#include <linux/mfd/wm8350/supply.h>
+
+#define WM8350_UNLOCK_KEY               0x0013
+#define WM8350_LOCK_KEY                 0x0000
+
+#define WM8350_CLOCK_CONTROL_1          0x28
+#define WM8350_AIF_TEST                 0x74
+
+/* debug */
+#define WM8350_BUS_DEBUG 0
+#if WM8350_BUS_DEBUG
+#define dump(regs, src) do { \
+        int i_; \
+        u16 *src_ = src; \
+        printk(KERN_DEBUG); \
+        for (i_ = 0; i_ < regs; i_++) \
+                printk(" 0x%4.4x", *src_++); \
+        printk("\n"); \
+} while (0);
+#else
+#define dump(bytes, src)
+#endif
+
+#define WM8350_LOCK_DEBUG 0
+#if WM8350_LOCK_DEBUG
+#define ldbg(format, arg...) printk(format, ## arg)
+#else
+#define ldbg(format, arg...)
+#endif
+
+/*
+ * WM8350 Device IO
+ */
+static DEFINE_MUTEX(io_mutex);
+static DEFINE_MUTEX(reg_lock_mutex);
+static DEFINE_MUTEX(auxadc_mutex);
+
+/* Perform a physical read from the device.
+ */
+static int wm8350_phys_read(struct wm8350 *wm8350, u8 reg, int num_regs,
+                            u16 *dest)
+{
+        int i, ret;
+        int bytes = num_regs * 2;
+
+        dev_dbg(wm8350->dev, "volatile read\n");
+        ret = wm8350->read_dev(wm8350, reg, bytes, (char *)dest);
+
+        for (i = reg; i < reg + num_regs; i++) {
+                /* Cache is CPU endian */
+                dest[i - reg] = be16_to_cpu(dest[i - reg]);
+
+                /* Satisfy non-volatile bits from cache */
+                dest[i - reg] &= wm8350_reg_io_map[i].vol;
+                dest[i - reg] |= wm8350->reg_cache[i];
+
+                /* Mask out non-readable bits */
+                dest[i - reg] &= wm8350_reg_io_map[i].readable;
+        }
+
+        dump(num_regs, dest);
+
+        return ret;
+}
+
+static int wm8350_read(struct wm8350 *wm8350, u8 reg, int num_regs, u16 *dest)
+{
+        int i;
+        int end = reg + num_regs;
+        int ret = 0;
+        int bytes = num_regs * 2;
+
+        if (wm8350->read_dev == NULL)
+                return -ENODEV;
+
+        if ((reg + num_regs - 1) > WM8350_MAX_REGISTER) {
+                dev_err(wm8350->dev, "invalid reg %x\n",
+                        reg + num_regs - 1);
+                return -EINVAL;
+        }
+
+        dev_dbg(wm8350->dev,
+                "%s R%d(0x%2.2x) %d regs\n", __func__, reg, reg, num_regs);
+
+#if WM8350_BUS_DEBUG
+        /* we can _safely_ read any register, but warn if read not supported */
+        for (i = reg; i < end; i++) {
+                if (!wm8350_reg_io_map[i].readable)
+                        dev_warn(wm8350->dev,
+                                "reg R%d is not readable\n", i);
+        }
+#endif
+
+        /* if any volatile registers are required, then read back all */
+        for (i = reg; i < end; i++)
+                if (wm8350_reg_io_map[i].vol)
+                        return wm8350_phys_read(wm8350, reg, num_regs, dest);
+
+        /* no volatiles, then cache is good */
+        dev_dbg(wm8350->dev, "cache read\n");
+        memcpy(dest, &wm8350->reg_cache[reg], bytes);
+        dump(num_regs, dest);
+        return ret;
+}
+
+static inline int is_reg_locked(struct wm8350 *wm8350, u8 reg)
+{
+        if (reg == WM8350_SECURITY ||
+            wm8350->reg_cache[WM8350_SECURITY] == WM8350_UNLOCK_KEY)
+                return 0;
+
+        if ((reg == WM8350_GPIO_CONFIGURATION_I_O) ||
+            (reg >= WM8350_GPIO_FUNCTION_SELECT_1 &&
+             reg <= WM8350_GPIO_FUNCTION_SELECT_4) ||
+            (reg >= WM8350_BATTERY_CHARGER_CONTROL_1 &&
+             reg <= WM8350_BATTERY_CHARGER_CONTROL_3))
+                return 1;
+        return 0;
+}
+
+static int wm8350_write(struct wm8350 *wm8350, u8 reg, int num_regs, u16 *src)
+{
+        int i;
+        int end = reg + num_regs;
+        int bytes = num_regs * 2;
+
+        if (wm8350->write_dev == NULL)
+                return -ENODEV;
+
+        if ((reg + num_regs - 1) > WM8350_MAX_REGISTER) {
+                dev_err(wm8350->dev, "invalid reg %x\n",
+                        reg + num_regs - 1);
+                return -EINVAL;
+        }
+
+        /* it's generally not a good idea to write to RO or locked registers */
+        for (i = reg; i < end; i++) {
+                if (!wm8350_reg_io_map[i].writable) {
+                        dev_err(wm8350->dev,
+                                "attempted write to read only reg R%d\n", i);
+                        return -EINVAL;
+                }
+
+                if (is_reg_locked(wm8350, i)) {
+                        dev_err(wm8350->dev,
+                               "attempted write to locked reg R%d\n", i);
+                        return -EINVAL;
+                }
+
+                src[i - reg] &= wm8350_reg_io_map[i].writable;
+
+                wm8350->reg_cache[i] =
+                        (wm8350->reg_cache[i] & ~wm8350_reg_io_map[i].writable)
+                        | src[i - reg];
+
+                src[i - reg] = cpu_to_be16(src[i - reg]);
+        }
+
+        /* Actually write it out */
+        return wm8350->write_dev(wm8350, reg, bytes, (char *)src);
+}
+
+/*
+ * Safe read, modify, write methods
+ */
+int wm8350_clear_bits(struct wm8350 *wm8350, u16 reg, u16 mask)
+{
+        u16 data;
+        int err;
+
+        mutex_lock(&io_mutex);
+        err = wm8350_read(wm8350, reg, 1, &data);
+        if (err) {
+                dev_err(wm8350->dev, "read from reg R%d failed\n", reg);
+                goto out;
+        }
+
+        data &= ~mask;
+        err = wm8350_write(wm8350, reg, 1, &data);
+        if (err)
+                dev_err(wm8350->dev, "write to reg R%d failed\n", reg);
+out:
+        mutex_unlock(&io_mutex);
+        return err;
+}
+EXPORT_SYMBOL_GPL(wm8350_clear_bits);
+
+int wm8350_set_bits(struct wm8350 *wm8350, u16 reg, u16 mask)
+{
+        u16 data;
+        int err;
+
+        mutex_lock(&io_mutex);
+        err = wm8350_read(wm8350, reg, 1, &data);
+        if (err) {
+                dev_err(wm8350->dev, "read from reg R%d failed\n", reg);
+                goto out;
+        }
+
+        data |= mask;
+        err = wm8350_write(wm8350, reg, 1, &data);
+        if (err)
+                dev_err(wm8350->dev, "write to reg R%d failed\n", reg);
+out:
+        mutex_unlock(&io_mutex);
+        return err;
+}
+EXPORT_SYMBOL_GPL(wm8350_set_bits);
+
+u16 wm8350_reg_read(struct wm8350 *wm8350, int reg)
+{
+        u16 data;
+        int err;
+
+        mutex_lock(&io_mutex);
+        err = wm8350_read(wm8350, reg, 1, &data);
+        if (err)
+                dev_err(wm8350->dev, "read from reg R%d failed\n", reg);
+
+        mutex_unlock(&io_mutex);
+        return data;
+}
+EXPORT_SYMBOL_GPL(wm8350_reg_read);
+
+int wm8350_reg_write(struct wm8350 *wm8350, int reg, u16 val)
+{
+        int ret;
+        u16 data = val;
+
+        mutex_lock(&io_mutex);
+        ret = wm8350_write(wm8350, reg, 1, &data);
+        if (ret)
+                dev_err(wm8350->dev, "write to reg R%d failed\n", reg);
+        mutex_unlock(&io_mutex);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(wm8350_reg_write);
+
+int wm8350_block_read(struct wm8350 *wm8350, int start_reg, int regs,
+                      u16 *dest)
+{
+        int err = 0;
+
+        mutex_lock(&io_mutex);
+        err = wm8350_read(wm8350, start_reg, regs, dest);
+        if (err)
+                dev_err(wm8350->dev, "block read starting from R%d failed\n",
+                        start_reg);
+        mutex_unlock(&io_mutex);
+        return err;
+}
+EXPORT_SYMBOL_GPL(wm8350_block_read);
+
+int wm8350_block_write(struct wm8350 *wm8350, int start_reg, int regs,
+                       u16 *src)
+{
+        int ret = 0;
+
+        mutex_lock(&io_mutex);
+        ret = wm8350_write(wm8350, start_reg, regs, src);
+        if (ret)
+                dev_err(wm8350->dev, "block write starting at R%d failed\n",
+                        start_reg);
+        mutex_unlock(&io_mutex);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(wm8350_block_write);
+
+int wm8350_reg_lock(struct wm8350 *wm8350)
+{
+        u16 key = WM8350_LOCK_KEY;
+        int ret;
+
+        ldbg(__func__);
+        mutex_lock(&io_mutex);
+        ret = wm8350_write(wm8350, WM8350_SECURITY, 1, &key);
+        if (ret)
+                dev_err(wm8350->dev, "lock failed\n");
+        mutex_unlock(&io_mutex);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(wm8350_reg_lock);
+
+int wm8350_reg_unlock(struct wm8350 *wm8350)
+{
+        u16 key = WM8350_UNLOCK_KEY;
+        int ret;
+
+        ldbg(__func__);
+        mutex_lock(&io_mutex);
+        ret = wm8350_write(wm8350, WM8350_SECURITY, 1, &key);
+        if (ret)
+                dev_err(wm8350->dev, "unlock failed\n");
+        mutex_unlock(&io_mutex);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(wm8350_reg_unlock);
+
+/*
+ * Cache is always host endian.
+ */
+static int wm8350_create_cache(struct wm8350 *wm8350, int mode)
+{
+        int i, ret = 0;
+        u16 value;
+        const u16 *reg_map;
+
+        switch (mode) {
+#ifdef CONFIG_MFD_WM8350_CONFIG_MODE_0
+        case 0:
+                reg_map = wm8350_mode0_defaults;
+                break;
+#endif
+#ifdef CONFIG_MFD_WM8350_CONFIG_MODE_1
+        case 1:
+                reg_map = wm8350_mode1_defaults;
+                break;
+#endif
+#ifdef CONFIG_MFD_WM8350_CONFIG_MODE_2
+        case 2:
+                reg_map = wm8350_mode2_defaults;
+                break;
+#endif
+#ifdef CONFIG_MFD_WM8350_CONFIG_MODE_3
+        case 3:
+                reg_map = wm8350_mode3_defaults;
+                break;
+#endif
+        default:
+                dev_err(wm8350->dev, "Configuration mode %d not supported\n",
+                        mode);
+                return -EINVAL;
+        }
+
+        wm8350->reg_cache =
+            kzalloc(sizeof(u16) * (WM8350_MAX_REGISTER + 1), GFP_KERNEL);
+        if (wm8350->reg_cache == NULL)
+                return -ENOMEM;
+
+        /* Read the initial cache state back from the device - this is
+         * a PMIC so the device many not be in a virgin state and we
+         * can't rely on the silicon values.
+         */
+        for (i = 0; i < WM8350_MAX_REGISTER; i++) {
+                /* audio register range */
+                if (wm8350_reg_io_map[i].readable &&
+                    (i < WM8350_CLOCK_CONTROL_1 || i > WM8350_AIF_TEST)) {
+                        ret = wm8350->read_dev(wm8350, i, 2, (char *)&value);
+                        if (ret < 0) {
+                                dev_err(wm8350->dev,
+                                       "failed to read initial cache value\n");
+                                goto out;
+                        }
+                        value = be16_to_cpu(value);
+                        value &= wm8350_reg_io_map[i].readable;
+                        wm8350->reg_cache[i] = value;
+                } else
+                        wm8350->reg_cache[i] = reg_map[i];
+        }
+
+out:
+        return ret;
+}
+EXPORT_SYMBOL_GPL(wm8350_create_cache);
+
+int wm8350_device_init(struct wm8350 *wm8350)
+{
+        int ret = -EINVAL;
+        u16 id1, id2, mask, mode;
+
+        /* get WM8350 revision and config mode */
+        wm8350->read_dev(wm8350, WM8350_RESET_ID, sizeof(id1), &id1);
+        wm8350->read_dev(wm8350, WM8350_ID, sizeof(id2), &id2);
+
+        id1 = be16_to_cpu(id1);
+        id2 = be16_to_cpu(id2);
+
+        if (id1 == 0x0)
+                dev_info(wm8350->dev, "Found Rev C device\n");
+        else if (id1 == 0x6143) {
+                switch ((id2 & WM8350_CHIP_REV_MASK) >> 12) {
+                case WM8350_REV_E:
+                        dev_info(wm8350->dev, "Found Rev E device\n");
+                        wm8350->rev = WM8350_REV_E;
+                        break;
+                case WM8350_REV_F:
+                        dev_info(wm8350->dev, "Found Rev F device\n");
+                        wm8350->rev = WM8350_REV_F;
+                        break;
+                case WM8350_REV_G:
+                        dev_info(wm8350->dev, "Found Rev G device\n");
+                        wm8350->rev = WM8350_REV_G;
+                        break;
+                default:
+                        /* For safety we refuse to run on unknown hardware */
+                        dev_info(wm8350->dev, "Found unknown rev\n");
+                        ret = -ENODEV;
+                        goto err;
+                }
+        } else {
+                dev_info(wm8350->dev, "Device with ID %x is not a WM8350\n",
+                         id1);
+                ret = -ENODEV;
+                goto err;
+        }
+
+        mode = id2 & WM8350_CONF_STS_MASK >> 10;
+        mask = id2 & WM8350_CUST_ID_MASK;
+        dev_info(wm8350->dev, "Config mode %d, ROM mask %d\n", mode, mask);
+
+        ret = wm8350_create_cache(wm8350, mode);
+        if (ret < 0) {
+                printk(KERN_ERR "wm8350: failed to create register cache\n");
+                return ret;
+        }
+
+        return 0;
+
+err:
+        kfree(wm8350->reg_cache);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(wm8350_device_init);
+
+void wm8350_device_exit(struct wm8350 *wm8350)
+{
+        kfree(wm8350->reg_cache);
+}
+EXPORT_SYMBOL_GPL(wm8350_device_exit);
+
+MODULE_LICENSE("GPL");