[PATCH v2 1/8] i2c: lpi2c: determine clk rate during probe

[Sascha Hauer]

The clock rate is not expected to change during runtime, so we can
determine it during probe instead of later when actually transferring
messages. This helps us to integrate PBL support into the driver where
we don't have clk_get_rate() available.

Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
 drivers/i2c/busses/i2c-imx-lpi2c.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c
index f28a445601..91203d90be 100644
--- a/drivers/i2c/busses/i2c-imx-lpi2c.c
+++ b/drivers/i2c/busses/i2c-imx-lpi2c.c
@@ -104,6 +104,7 @@ struct lpi2c_imx_struct {
 	unsigned int		txfifosize;
 	unsigned int		rxfifosize;
 	enum lpi2c_imx_mode	mode;
+	unsigned long		clk_rate;
 };
 
 static void lpi2c_imx_intctrl(struct lpi2c_imx_struct *lpi2c_imx,
@@ -197,23 +198,19 @@ static void lpi2c_imx_stop(struct lpi2c_imx_struct *lpi2c_imx)
 static int lpi2c_imx_config(struct lpi2c_imx_struct *lpi2c_imx)
 {
 	u8 prescale, filt, sethold, datavd;
-	unsigned int clk_rate, clk_cycle, clkhi, clklo;
+	unsigned int clk_cycle, clkhi, clklo;
 	enum lpi2c_imx_pincfg pincfg;
 	unsigned int temp;
 
 	lpi2c_imx_set_mode(lpi2c_imx);
 
-	clk_rate = clk_get_rate(lpi2c_imx->clks[0].clk);
-	if (!clk_rate)
-		return -EINVAL;
-
 	if (lpi2c_imx->mode == HS || lpi2c_imx->mode == ULTRA_FAST)
 		filt = 0;
 	else
 		filt = 2;
 
 	for (prescale = 0; prescale <= 7; prescale++) {
-		clk_cycle = clk_rate / ((1 << prescale) * lpi2c_imx->bitrate)
+		clk_cycle = lpi2c_imx->clk_rate / ((1 << prescale) * lpi2c_imx->bitrate)
 			    - 3 - (filt >> 1);
 		clkhi = DIV_ROUND_UP(clk_cycle, I2C_CLK_RATIO + 1);
 		clklo = clk_cycle - clkhi;
@@ -493,6 +490,8 @@ static int lpi2c_imx_probe(struct device *dev)
 	if (ret)
 		return ret;
 
+	lpi2c_imx->clk_rate = clk_get_rate(lpi2c_imx->clks[0].clk);
+
 	temp = readl(lpi2c_imx->base + LPI2C_PARAM);
 	lpi2c_imx->txfifosize = 1 << (temp & 0x0f);
 	lpi2c_imx->rxfifosize = 1 << ((temp >> 8) & 0x0f);
-- 
2.39.2