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..0754c5e9 100644
--- a/drivers/mfd/stmpe.c
+++ b/drivers/mfd/stmpe.c
@@ -455,6 +455,67 @@
},
};
+/* 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 @@
.num_irqs = STMPE1601_NR_INTERNAL_IRQS,
.enable = stmpe1601_enable,
.get_altfunc = stmpe1601_get_altfunc,
+ .enable_autosleep = stmpe1601_autosleep,
};
/*
@@ -589,6 +651,7 @@
.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 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 @@
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);
}