[PATCH v2] i2c: stm32f7: do not backup read-only PECR register

From: Alain Volmat
Date: Tue Mar 10 2020 - 07:58:59 EST


The PECR register provides received packet computed PEC value.Â
It makes no sense restoring its value after a reset, and anyway,
as read-only register it cannot be restored.

Fixes: ea6dd25deeb5 ("i2c: stm32f7: add PM_SLEEP suspend/resume support")
Signed-off-by: Alain Volmat <alain.volmat@xxxxxx>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@xxxxxx>
---
v2: rebase on top of other i2c-stm32f7 patches integrated within i2c-next

drivers/i2c/busses/i2c-stm32f7.c | 4 ----
1 file changed, 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
index 8fe7f8caf91b..6418f5982894 100644
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -176,7 +176,6 @@
* @cr2: Control register 2
* @oar1: Own address 1 register
* @oar2: Own address 2 register
- * @pecr: PEC register
* @tmgr: Timing register
*/
struct stm32f7_i2c_regs {
@@ -184,7 +183,6 @@ struct stm32f7_i2c_regs {
u32 cr2;
u32 oar1;
u32 oar2;
- u32 pecr;
u32 tmgr;
};

@@ -2196,7 +2194,6 @@ static int stm32f7_i2c_regs_backup(struct stm32f7_i2c_dev *i2c_dev)
backup_regs->cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
backup_regs->oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1);
backup_regs->oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2);
- backup_regs->pecr = readl_relaxed(i2c_dev->base + STM32F7_I2C_PECR);
backup_regs->tmgr = readl_relaxed(i2c_dev->base + STM32F7_I2C_TIMINGR);
stm32f7_i2c_write_fm_plus_bits(i2c_dev, false);

@@ -2229,7 +2226,6 @@ static int stm32f7_i2c_regs_restore(struct stm32f7_i2c_dev *i2c_dev)
writel_relaxed(backup_regs->cr2, i2c_dev->base + STM32F7_I2C_CR2);
writel_relaxed(backup_regs->oar1, i2c_dev->base + STM32F7_I2C_OAR1);
writel_relaxed(backup_regs->oar2, i2c_dev->base + STM32F7_I2C_OAR2);
- writel_relaxed(backup_regs->pecr, i2c_dev->base + STM32F7_I2C_PECR);
stm32f7_i2c_write_fm_plus_bits(i2c_dev, true);

pm_runtime_put_sync(i2c_dev->dev);
--
2.7.4