[PATCH v3 5/9] i2c: stm32f7: perform I2C_ISR read once at beginning of event isr

From: Alain Volmat
Date: Fri Dec 15 2023 - 12:10:15 EST


Move readl_relaxed of I2C_ISR register at beginning of event isr
so that it done once for both master & slave handling.

Signed-off-by: Alain Volmat <alain.volmat@xxxxxxxxxxx>
---
drivers/i2c/busses/i2c-stm32f7.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
index 15100fed0a3f..f7abf6d3a7b9 100644
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -1419,15 +1419,13 @@ static bool stm32f7_i2c_is_slave_busy(struct stm32f7_i2c_dev *i2c_dev)
return i == busy;
}

-static irqreturn_t stm32f7_i2c_slave_isr_event(struct stm32f7_i2c_dev *i2c_dev)
+static irqreturn_t stm32f7_i2c_slave_isr_event(struct stm32f7_i2c_dev *i2c_dev, u32 status)
{
void __iomem *base = i2c_dev->base;
- u32 cr2, status, mask;
+ u32 cr2, mask;
u8 val;
int ret;

- status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
-
/* Slave transmitter mode */
if (status & STM32F7_I2C_ISR_TXIS) {
i2c_slave_event(i2c_dev->slave_running,
@@ -1531,11 +1529,11 @@ static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data)
u32 status, mask;
int ret;

- if (!i2c_dev->master_mode)
- return stm32f7_i2c_slave_isr_event(i2c_dev);
-
status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);

+ if (!i2c_dev->master_mode)
+ return stm32f7_i2c_slave_isr_event(i2c_dev, status);
+
/* NACK received */
if (status & STM32F7_I2C_ISR_NACKF) {
dev_dbg(i2c_dev->dev, "<%s>: Receive NACK (addr %x)\n",
--
2.25.1