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i2c: rcar_i2c: Fix order of restart and clear status

In case of repeated START condition, the restart has to be kicked
before clear status (MSR register). If it is kicked after clear status,
R-Car I2C may transfer data (TXD register) or receive data (RXD register)
instead of transferring slave address (MAR register).

Signed-off-by: Ryo Kataoka <ryo.kataoka.wt@renesas.com>
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Nobuhiro Iwamatsu 10 лет назад
Родитель
Сommit
cd818a381d
1 измененных файлов с 2 добавлено и 2 удалено
  1. 2 2
      drivers/i2c/rcar_i2c.c

+ 2 - 2
drivers/i2c/rcar_i2c.c

@@ -119,10 +119,10 @@ rcar_i2c_raw_read(struct rcar_i2c *dev, u8 chip, uint addr)
 
 	/* set slave address, receive */
 	writel((chip << 1) | 1, &dev->icmar);
-	/* clear status */
-	writel(0, &dev->icmsr);
 	/* start master receive */
 	writel(MCR_MDBS | MCR_MIE | MCR_ESG, &dev->icmcr);
+	/* clear status */
+	writel(0, &dev->icmsr);
 
 	while ((readl(&dev->icmsr) & (MSR_MAT | MSR_MDR))
 		!= (MSR_MAT | MSR_MDR))