[PATCH v2 04/10] gpio: stmpe: write int status register only when needed

From: patrice.chotard
Date: Thu Apr 28 2016 - 08:14:55 EST


From: Patrice Chotard <patrice.chotard@xxxxxx>

On STMPE801/1801 datasheets, it's mentionned writing
in interrupt status register has no effect, bits are
cleared when reading.

Signed-off-by: Amelie DELAUNAY <amelie.delaunay@xxxxxx>
Signed-off-by: Patrice Chotard <patrice.chotard@xxxxxx>
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
drivers/gpio/gpio-stmpe.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/gpio/gpio-stmpe.c b/drivers/gpio/gpio-stmpe.c
index bfc918c..2789bdc 100644
--- a/drivers/gpio/gpio-stmpe.c
+++ b/drivers/gpio/gpio-stmpe.c
@@ -355,12 +355,16 @@ static irqreturn_t stmpe_gpio_irq(int irq, void *dev)
stat &= ~(1 << bit);
}

- stmpe_reg_write(stmpe, statmsbreg + i, status[i]);
-
- /* Edge detect register is not present on 801 and 1801 */
- if (stmpe->partnum != STMPE801 || stmpe->partnum != STMPE1801)
+ /*
+ * interrupt status register write has no effect on
+ * 801 and 1801, bits are cleared when read.
+ * Edge detect register is not present on 801 and 1801
+ */
+ if (stmpe->partnum != STMPE801 || stmpe->partnum != STMPE1801) {
+ stmpe_reg_write(stmpe, statmsbreg + i, status[i]);
stmpe_reg_write(stmpe, stmpe->regs[STMPE_IDX_GPEDR_MSB]
+ i, status[i]);
+ }
}

return IRQ_HANDLED;
--
1.9.1