linux-kernel - [PATCH v4 02/11] i2c: riic: Call pm_runtime_get

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Message-Id: <20240819102348.1592171-3-claudiu.beznea.uj@bp.renesas.com>
Date: Mon, 19 Aug 2024 13:23:39 +0300
From: Claudiu <claudiu.beznea@...on.dev>
To: chris.brandt@...esas.com,
	andi.shyti@...nel.org,
	robh@...nel.org,
	krzk+dt@...nel.org,
	conor+dt@...nel.org,
	geert+renesas@...der.be,
	magnus.damm@...il.com,
	p.zabel@...gutronix.de,
	wsa+renesas@...g-engineering.com
Cc: linux-renesas-soc@...r.kernel.org,
	linux-i2c@...r.kernel.org,
	devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	claudiu.beznea@...on.dev,
	Claudiu Beznea <claudiu.beznea.uj@...renesas.com>
Subject: [PATCH v4 02/11] i2c: riic: Call pm_runtime_get_sync() when need to access registers

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

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@...nel.org>
Reviewed-by: Wolfram Sang <wsa+renesas@...g-engineering.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@...renesas.com>
---

Changes in v4:
- collected tags

Changes in v3:
- collected tags

Changes in v2:
- none

 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 bc33762a5d07..2e119024c2d7 100644
--- a/drivers/i2c/busses/i2c-riic.c
+++ b/drivers/i2c/busses/i2c-riic.c
@@ -301,19 +301,15 @@ 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);
@@ -351,8 +347,7 @@ 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;
@@ -384,6 +379,8 @@ 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);
@@ -397,9 +394,8 @@ 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[] = {
-- 
2.39.2