spi: dw-mid: get a proper clock frequency for SPI2

The clock information is being kept in the custom register on Intel MID
platforms. Each controller has its own dedicated custom register for that.
Thus, to get a proper frequency we have to read value from the specific offset
to the register block. This patch makes this happen.

Fixes: d58cf5ff6500 (spi: dw-pci: describe Intel MID controllers better)
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-dw-mid.c

@@ -247,9 +247,9 @@ static struct dw_spi_dma_ops mid_dma_ops = {
 
 /* Some specific info for SPI0 controller on Intel MID */
 
-/* HW info for MRST CLk Control Unit, one 32b reg */
+/* HW info for MRST Clk Control Unit, 32b reg per controller */
 #define MRST_SPI_CLK_BASE	100000000	/* 100m */
-#define MRST_CLK_SPI0_REG	0xff11d86c
+#define MRST_CLK_SPI_REG	0xff11d86c
 #define CLK_SPI_BDIV_OFFSET	0
 #define CLK_SPI_BDIV_MASK	0x00000007
 #define CLK_SPI_CDIV_OFFSET	9
@@ -261,13 +261,16 @@ int dw_spi_mid_init(struct dw_spi *dws)
 	void __iomem *clk_reg;
 	u32 clk_cdiv;
 
-	clk_reg = ioremap_nocache(MRST_CLK_SPI0_REG, 16);
+	clk_reg = ioremap_nocache(MRST_CLK_SPI_REG, 16);
 	if (!clk_reg)
 		return -ENOMEM;
 
-	/* get SPI controller operating freq info */
-	clk_cdiv  = (readl(clk_reg) & CLK_SPI_CDIV_MASK) >> CLK_SPI_CDIV_OFFSET;
+	/* Get SPI controller operating freq info */
+	clk_cdiv = readl(clk_reg + dws->bus_num * sizeof(u32));
+	clk_cdiv &= CLK_SPI_CDIV_MASK;
+	clk_cdiv >>= CLK_SPI_CDIV_OFFSET;
 	dws->max_freq = MRST_SPI_CLK_BASE / (clk_cdiv + 1);
+
 	iounmap(clk_reg);
 
 #ifdef CONFIG_SPI_DW_MID_DMA

drivers/spi/spi-dw-pci.c

@@ -82,14 +82,14 @@ static int spi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	 * clock rate, FIFO depth.
 	 */
 	if (desc) {
+		dws->num_cs = desc->num_cs;
+		dws->bus_num = desc->bus_num;
+
 		if (desc->setup) {
 			ret = desc->setup(dws);
 			if (ret)
 				return ret;
 		}
-
-		dws->num_cs = desc->num_cs;
-		dws->bus_num = desc->bus_num;
 	} else {
 		return -ENODEV;
 	}