mfd: Add companion chip in 88pm80x

in hw design, 800 is mainly for pmic control, while 805 for audio.
but there are 3 registers which controls class D speaker property,
and they are defined in 800 i2c client domain. so 805 codec driver
needs to use 800 i2c client to access class D speaker reg for
audio path management. so add this workaround for the purpose to
let 805 access 800 i2c in some scenario.

Signed-off-by: Qiao Zhou <zhouqiao@marvell.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

diff --git a/drivers/mfd/88pm80x.c b/drivers/mfd/88pm80x.c
index 90aa18a..77b8655 100644 (file)
--- a/drivers/mfd/88pm80x.c
+++ b/drivers/mfd/88pm80x.c
@@ -18,6 +18,12 @@
 #include <linux/uaccess.h>
 #include <linux/err.h>
 
+/*
+ * workaround: some registers needed by pm805 are defined in pm800, so
+ * need to use this global variable to maintain the relation between
+ * pm800 and pm805. would remove it after HW chip fixes the issue.
+ */
+static struct pm80x_chip *g_pm80x_chip;
 
 const struct regmap_config pm80x_regmap_config = {
        .reg_bits = 8,
@@ -61,6 +67,19 @@ int __devinit pm80x_init(struct i2c_client *client,
 
        device_init_wakeup(&client->dev, 1);
 
+       /*
+        * workaround: set g_pm80x_chip to the first probed chip. if the
+        * second chip is probed, just point to the companion to each
+        * other so that pm805 can access those specific register. would
+        * remove it after HW chip fixes the issue.
+        */
+       if (!g_pm80x_chip)
+               g_pm80x_chip = chip;
+       else {
+               chip->companion = g_pm80x_chip->client;
+               g_pm80x_chip->companion = chip->client;
+       }
+
        return 0;
 
 err_chip_id:
@@ -75,6 +94,15 @@ int __devexit pm80x_deinit(struct i2c_client *client)
 {
        struct pm80x_chip *chip = i2c_get_clientdata(client);
 
+       /*
+        * workaround: clear the dependency between pm800 and pm805.
+        * would remove it after HW chip fixes the issue.
+        */
+       if (g_pm80x_chip->companion)
+               g_pm80x_chip->companion = NULL;
+       else
+               g_pm80x_chip = NULL;
+
        regmap_exit(chip->regmap);
        devm_kfree(&client->dev, chip);
 

diff --git a/include/linux/mfd/88pm80x.h b/include/linux/mfd/88pm80x.h
index 6c126e9..103f06d 100644 (file)
--- a/include/linux/mfd/88pm80x.h
+++ b/include/linux/mfd/88pm80x.h
@@ -295,6 +295,7 @@ struct pm80x_chip {
        struct pm80x_subchip *subchip;
        struct device *dev;
        struct i2c_client *client;
+       struct i2c_client *companion;
        struct regmap *regmap;
        struct regmap_irq_chip *regmap_irq_chip;
        struct regmap_irq_chip_data *irq_data;