[PATCH 6.1.y-cip 02/15] i2c: riic: Call pm_runtime_get_sync() when need to access registers

Lad Prabhakar
2025-04-25T09:11:07Z

From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

commit a1ecb041589017ce4e03d92f3b9a92a2a8a37ceb upstream.

There is no need to runtime resume the device as long as the IP registers
are not accessed. Calling pm_runtime_get_sync() at the register access
time leads to a simpler error path.

Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
drivers/i2c/busses/i2c-riic.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/drivers/i2c/busses/i2c-riic.c b/drivers/i2c/busses/i2c-riic.c
index ea2c894600d52..531210f55abac 100644
--- a/drivers/i2c/busses/i2c-riic.c
+++ b/drivers/i2c/busses/i2c-riic.c
@@ -302,19 +302,15 @@ static const struct i2c_algorithm riic_algo = {

static int riic_init_hw(struct riic_dev *riic, struct i2c_timings *t)
{
- int ret = 0;
unsigned long rate;
int total_ticks, cks, brl, brh;
struct device *dev = riic->adapter.dev.parent;

- pm_runtime_get_sync(dev);
-
if (t->bus_freq_hz > I2C_MAX_FAST_MODE_FREQ) {
dev_err(&riic->adapter.dev,
"unsupported bus speed (%dHz). %d max\n",
t->bus_freq_hz, I2C_MAX_FAST_MODE_FREQ);
- ret = -EINVAL;
- goto out;
+ return -EINVAL;
}

rate = clk_get_rate(riic->clk);
@@ -352,8 +348,7 @@ static int riic_init_hw(struct riic_dev *riic, struct i2c_timings *t)
if (brl > (0x1F + 3)) {
dev_err(&riic->adapter.dev, "invalid speed (%lu). Too slow.\n",
(unsigned long)t->bus_freq_hz);
- ret = -EINVAL;
- goto out;
+ return -EINVAL;
}

brh = total_ticks - brl;
@@ -385,6 +380,8 @@ static int riic_init_hw(struct riic_dev *riic, struct i2c_timings *t)
t->scl_fall_ns / (1000000000 / rate),
t->scl_rise_ns / (1000000000 / rate), cks, brl, brh);

+ pm_runtime_get_sync(dev);
+
/* Changing the order of accessing IICRST and ICE may break things! */
riic_writeb(riic, ICCR1_IICRST | ICCR1_SOWP, RIIC_ICCR1);
riic_clear_set_bit(riic, 0, ICCR1_ICE, RIIC_ICCR1);
@@ -398,9 +395,8 @@ static int riic_init_hw(struct riic_dev *riic, struct i2c_timings *t)

riic_clear_set_bit(riic, ICCR1_IICRST, 0, RIIC_ICCR1);

-out:
pm_runtime_put(dev);
- return ret;
+ return 0;
}

static struct riic_irq_desc riic_irqs[] = {
--
2.43.0