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

[patrice.chotard]

From: Patrice Chotard <patrice.chot...@st.com>

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.delau...@st.com>
Signed-off-by: Patrice Chotard <patrice.chot...@st.com>
Reviewed-by: Linus Walleij <linus.wall...@linaro.org>
---
 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