mfd: Add stmpe auto sleep feature

Some STMPE devices support entering sleep mode automatically on a
specified timeout of inactivity on the I2C bus with the host system.

Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Sundar R Iyer <sundar.iyer@stericsson.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

diff --git a/drivers/mfd/stmpe.c b/drivers/mfd/stmpe.c
index a7f3099..0754c5e 100644 (file)
--- a/drivers/mfd/stmpe.c
+++ b/drivers/mfd/stmpe.c
@@ -455,6 +455,67 @@ static struct stmpe_variant_block stmpe1601_blocks[] = {
        },
 };
 
+/* supported autosleep timeout delay (in msecs) */
+static const int stmpe_autosleep_delay[] = {
+       4, 16, 32, 64, 128, 256, 512, 1024,
+};
+
+static int stmpe_round_timeout(int timeout)
+{
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(stmpe_autosleep_delay); i++) {
+               if (stmpe_autosleep_delay[i] >= timeout)
+                       return i;
+       }
+
+       /*
+        * requests for delays longer than supported should not return the
+        * longest supported delay
+        */
+       return -EINVAL;
+}
+
+static int stmpe_autosleep(struct stmpe *stmpe, int autosleep_timeout)
+{
+       int ret;
+
+       if (!stmpe->variant->enable_autosleep)
+               return -ENOSYS;
+
+       mutex_lock(&stmpe->lock);
+       ret = stmpe->variant->enable_autosleep(stmpe, autosleep_timeout);
+       mutex_unlock(&stmpe->lock);
+
+       return ret;
+}
+
+/*
+ * Both stmpe 1601/2403 support same layout for autosleep
+ */
+static int stmpe1601_autosleep(struct stmpe *stmpe,
+               int autosleep_timeout)
+{
+       int ret, timeout;
+
+       /* choose the best available timeout */
+       timeout = stmpe_round_timeout(autosleep_timeout);
+       if (timeout < 0) {
+               dev_err(stmpe->dev, "invalid timeout\n");
+               return timeout;
+       }
+
+       ret = __stmpe_set_bits(stmpe, STMPE1601_REG_SYS_CTRL2,
+                       STMPE1601_AUTOSLEEP_TIMEOUT_MASK,
+                       timeout);
+       if (ret < 0)
+               return ret;
+
+       return __stmpe_set_bits(stmpe, STMPE1601_REG_SYS_CTRL2,
+                       STPME1601_AUTOSLEEP_ENABLE,
+                       STPME1601_AUTOSLEEP_ENABLE);
+}
+
 static int stmpe1601_enable(struct stmpe *stmpe, unsigned int blocks,
                            bool enable)
 {
@@ -497,6 +558,7 @@ static struct stmpe_variant_info stmpe1601 = {
        .num_irqs       = STMPE1601_NR_INTERNAL_IRQS,
        .enable         = stmpe1601_enable,
        .get_altfunc    = stmpe1601_get_altfunc,
+       .enable_autosleep       = stmpe1601_autosleep,
 };
 
 /*
@@ -589,6 +651,7 @@ static struct stmpe_variant_info stmpe2403 = {
        .num_irqs       = STMPE24XX_NR_INTERNAL_IRQS,
        .enable         = stmpe24xx_enable,
        .get_altfunc    = stmpe24xx_get_altfunc,
+       .enable_autosleep       = stmpe1601_autosleep, /* same as stmpe1601 */
 };
 
 static struct stmpe_variant_info *stmpe_variant_info[] = {
@@ -731,6 +794,7 @@ static void stmpe_irq_remove(struct stmpe *stmpe)
 static int __devinit stmpe_chip_init(struct stmpe *stmpe)
 {
        unsigned int irq_trigger = stmpe->pdata->irq_trigger;
+       int autosleep_timeout = stmpe->pdata->autosleep_timeout;
        struct stmpe_variant_info *variant = stmpe->variant;
        u8 icr = STMPE_ICR_LSB_GIM;
        unsigned int id;
@@ -766,6 +830,12 @@ static int __devinit stmpe_chip_init(struct stmpe *stmpe)
        if (stmpe->pdata->irq_invert_polarity)
                icr ^= STMPE_ICR_LSB_HIGH;
 
+       if (stmpe->pdata->autosleep) {
+               ret = stmpe_autosleep(stmpe, autosleep_timeout);
+               if (ret)
+                       return ret;
+       }
+
        return stmpe_reg_write(stmpe, stmpe->regs[STMPE_IDX_ICR_LSB], icr);
 }
 

diff --git a/drivers/mfd/stmpe.h b/drivers/mfd/stmpe.h
index 991f0ec..0dbdc4e 100644 (file)
--- a/drivers/mfd/stmpe.h
+++ b/drivers/mfd/stmpe.h
@@ -49,6 +49,7 @@ struct stmpe_variant_block {
  *             Called with the I/O lock held.
  * @get_altfunc: callback to get the alternate function number for the
  *              specific block
+ * @enable_autosleep: callback to configure autosleep with specified timeout
  */
 struct stmpe_variant_info {
        const char *name;
@@ -62,6 +63,7 @@ struct stmpe_variant_info {
        int num_irqs;
        int (*enable)(struct stmpe *stmpe, unsigned int blocks, bool enable);
        int (*get_altfunc)(struct stmpe *stmpe, enum stmpe_block block);
+       int (*enable_autosleep)(struct stmpe *stmpe, int autosleep_timeout);
 };
 
 #define STMPE_ICR_LSB_HIGH     (1 << 2)
@@ -118,6 +120,7 @@ struct stmpe_variant_info {
 #define STMPE1601_NR_INTERNAL_IRQS     9
 
 #define STMPE1601_REG_SYS_CTRL                 0x02
+#define STMPE1601_REG_SYS_CTRL2                        0x03
 #define STMPE1601_REG_ICR_LSB                  0x11
 #define STMPE1601_REG_IER_LSB                  0x13
 #define STMPE1601_REG_ISR_MSB                  0x14
@@ -137,6 +140,10 @@ struct stmpe_variant_info {
 #define STMPE1601_SYS_CTRL_ENABLE_KPC          (1 << 1)
 #define STMPE1601_SYSCON_ENABLE_SPWM           (1 << 0)
 
+/* The 1601/2403 share the same masks */
+#define STMPE1601_AUTOSLEEP_TIMEOUT_MASK       (0x7)
+#define STPME1601_AUTOSLEEP_ENABLE             (1 << 3)
+
 /*
  * STMPE24xx
  */

diff --git a/include/linux/mfd/stmpe.h b/include/linux/mfd/stmpe.h
index 90faa98..39ca758 100644 (file)
--- a/include/linux/mfd/stmpe.h
+++ b/include/linux/mfd/stmpe.h
@@ -170,6 +170,8 @@ struct stmpe_ts_platform_data {
  * @blocks: bitmask of blocks to enable (use STMPE_BLOCK_*)
  * @irq_trigger: IRQ trigger to use for the interrupt to the host
  * @irq_invert_polarity: IRQ line is connected with reversed polarity
+ * @autosleep: bool to enable/disable stmpe autosleep
+ * @autosleep_timeout: inactivity timeout in milliseconds for autosleep
  * @irq_base: base IRQ number.  %STMPE_NR_IRQS irqs will be used, or
  *           %STMPE_NR_INTERNAL_IRQS if the GPIO driver is not used.
  * @gpio: GPIO-specific platform data
@@ -182,6 +184,8 @@ struct stmpe_platform_data {
        int irq_base;
        unsigned int irq_trigger;
        bool irq_invert_polarity;
+       bool autosleep;
+       int autosleep_timeout;
 
        struct stmpe_gpio_platform_data *gpio;
        struct stmpe_keypad_platform_data *keypad;