spi: imx: add a check for speed_hz before calculating the clock

When some drivers use spi to send data, spi_transfer->speed_hz is
not assigned. If spidev->max_speed_hz is not assigned as well, it
will cause an error in configuring the clock.
Add a check for these two values before configuring the clock. An
error will be returned when they are not assigned.
Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Link: https://lore.kernel.org/r/20210408103347.244313-2-xiaoning.wang@nxp.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-imx.c

@@ -66,8 +66,7 @@ struct spi_imx_data;
 struct spi_imx_devtype_data {
 	void (*intctrl)(struct spi_imx_data *, int);
 	int (*prepare_message)(struct spi_imx_data *, struct spi_message *);
-	int (*prepare_transfer)(struct spi_imx_data *, struct spi_device *,
-				struct spi_transfer *);
+	int (*prepare_transfer)(struct spi_imx_data *, struct spi_device *);
 	void (*trigger)(struct spi_imx_data *);
 	int (*rx_available)(struct spi_imx_data *);
 	void (*reset)(struct spi_imx_data *);
@@ -572,11 +571,10 @@ static int mx51_ecspi_prepare_message(struct spi_imx_data *spi_imx,
 }
 
 static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx,
-				       struct spi_device *spi,
-				       struct spi_transfer *t)
+				       struct spi_device *spi)
 {
 	u32 ctrl = readl(spi_imx->base + MX51_ECSPI_CTRL);
-	u32 clk = t->speed_hz, delay;
+	u32 clk, delay;
 
 	/* Clear BL field and set the right value */
 	ctrl &= ~MX51_ECSPI_CTRL_BL_MASK;
@@ -590,7 +588,7 @@ static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx,
 	/* set clock speed */
 	ctrl &= ~(0xf << MX51_ECSPI_CTRL_POSTDIV_OFFSET |
 		  0xf << MX51_ECSPI_CTRL_PREDIV_OFFSET);
-	ctrl |= mx51_ecspi_clkdiv(spi_imx, t->speed_hz, &clk);
+	ctrl |= mx51_ecspi_clkdiv(spi_imx, spi_imx->spi_bus_clk, &clk);
 	spi_imx->spi_bus_clk = clk;
 
 	if (spi_imx->usedma)
@@ -702,13 +700,12 @@ static int mx31_prepare_message(struct spi_imx_data *spi_imx,
 }
 
 static int mx31_prepare_transfer(struct spi_imx_data *spi_imx,
-				 struct spi_device *spi,
-				 struct spi_transfer *t)
+				 struct spi_device *spi)
 {
 	unsigned int reg = MX31_CSPICTRL_ENABLE | MX31_CSPICTRL_MASTER;
 	unsigned int clk;
 
-	reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, t->speed_hz, &clk) <<
+	reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, spi_imx->spi_bus_clk, &clk) <<
 		MX31_CSPICTRL_DR_SHIFT;
 	spi_imx->spi_bus_clk = clk;
 
@@ -807,14 +804,13 @@ static int mx21_prepare_message(struct spi_imx_data *spi_imx,
 }
 
 static int mx21_prepare_transfer(struct spi_imx_data *spi_imx,
-				 struct spi_device *spi,
-				 struct spi_transfer *t)
+				 struct spi_device *spi)
 {
 	unsigned int reg = MX21_CSPICTRL_ENABLE | MX21_CSPICTRL_MASTER;
 	unsigned int max = is_imx27_cspi(spi_imx) ? 16 : 18;
 	unsigned int clk;
 
-	reg |= spi_imx_clkdiv_1(spi_imx->spi_clk, t->speed_hz, max, &clk)
+	reg |= spi_imx_clkdiv_1(spi_imx->spi_clk, spi_imx->spi_bus_clk, max, &clk)
 		<< MX21_CSPICTRL_DR_SHIFT;
 	spi_imx->spi_bus_clk = clk;
 
@@ -883,13 +879,12 @@ static int mx1_prepare_message(struct spi_imx_data *spi_imx,
 }
 
 static int mx1_prepare_transfer(struct spi_imx_data *spi_imx,
-				struct spi_device *spi,
-				struct spi_transfer *t)
+				struct spi_device *spi)
 {
 	unsigned int reg = MX1_CSPICTRL_ENABLE | MX1_CSPICTRL_MASTER;
 	unsigned int clk;
 
-	reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, t->speed_hz, &clk) <<
+	reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, spi_imx->spi_bus_clk, &clk) <<
 		MX1_CSPICTRL_DR_SHIFT;
 	spi_imx->spi_bus_clk = clk;
 
@@ -1168,6 +1163,16 @@ static int spi_imx_setupxfer(struct spi_device *spi,
 	if (!t)
 		return 0;
 
+	if (!t->speed_hz) {
+		if (!spi->max_speed_hz) {
+			dev_err(&spi->dev, "no speed_hz provided!\n");
+			return -EINVAL;
+		}
+		dev_dbg(&spi->dev, "using spi->max_speed_hz!\n");
+		spi_imx->spi_bus_clk = spi->max_speed_hz;
+	} else
+		spi_imx->spi_bus_clk = t->speed_hz;
+
 	spi_imx->bits_per_word = t->bits_per_word;
 
 	/*
@@ -1209,7 +1214,7 @@ static int spi_imx_setupxfer(struct spi_device *spi,
 		spi_imx->slave_burst = t->len;
 	}
 
-	spi_imx->devtype_data->prepare_transfer(spi_imx, spi, t);
+	spi_imx->devtype_data->prepare_transfer(spi_imx, spi);
 
 	return 0;
 }