spi: mvebu_a3700_spi: Use Armada 37xx clk driver for SPI clock frequency

Since now we have driver for clocks on Armada 37xx, use it to determine
SQF clock frequency for the SPI driver.

Also change the default config files for Armada 37xx devices so that
the clock driver is enabled by default, otherwise the SPI driver cannot
be enabled.

Signed-off-by: Marek Behun <marek.behun@nic.cz>
Signed-off-by: Stefan Roese <sr@denx.de>

arch/arm/dts/armada-37xx.dtsi

@@ -301,8 +301,8 @@
 				#address-cells = <1>;
 				#size-cells = <0>;
 				#clock-cells = <0>;
-				clock-frequency = <160000>;
-				spi-max-frequency = <40000>;
+				spi-max-frequency = <50000000>;
+				clocks = <&nb_periph_clk 7>;
 				status = "disabled";
 			};
 

configs/mvebu_db-88f3720_defconfig

@@ -36,6 +36,9 @@ CONFIG_DM_GPIO=y
 # CONFIG_MVEBU_GPIO is not set
 CONFIG_DM_I2C=y
 CONFIG_MISC=y
+CONFIG_CLK=y
+CONFIG_CLK_MVEBU=y
+CONFIG_CLK_ARMADA_3720=y
 CONFIG_DM_MMC=y
 CONFIG_MMC_SDHCI=y
 CONFIG_MMC_SDHCI_SDMA=y

configs/mvebu_espressobin-88f3720_defconfig

@@ -35,6 +35,9 @@ CONFIG_BLOCK_CACHE=y
 CONFIG_DM_GPIO=y
 CONFIG_DM_I2C=y
 CONFIG_MISC=y
+CONFIG_CLK=y
+CONFIG_CLK_MVEBU=y
+CONFIG_CLK_ARMADA_3720=y
 CONFIG_DM_MMC=y
 CONFIG_MMC_SDHCI=y
 CONFIG_MMC_SDHCI_SDMA=y

drivers/spi/Kconfig

@@ -104,6 +104,7 @@ config ICH_SPI
 
 config MVEBU_A3700_SPI
 	bool "Marvell Armada 3700 SPI driver"
+	select CLK_ARMADA_3720
 	help
 	  Enable the Marvell Armada 3700 SPI driver. This driver can be
 	  used to access the SPI NOR flash on platforms embedding this

drivers/spi/mvebu_a3700_spi.c

@@ -9,6 +9,7 @@
 #include <dm.h>
 #include <malloc.h>
 #include <spi.h>
+#include <clk.h>
 #include <wait_bit.h>
 #include <asm/io.h>
 
@@ -21,9 +22,8 @@ DECLARE_GLOBAL_DATA_PTR;
 #define MVEBU_SPI_A3700_CLK_POL			BIT(7)
 #define MVEBU_SPI_A3700_FIFO_EN			BIT(17)
 #define MVEBU_SPI_A3700_SPI_EN_0		BIT(16)
-#define MVEBU_SPI_A3700_CLK_PRESCALE_BIT	0
-#define MVEBU_SPI_A3700_CLK_PRESCALE_MASK	\
-	(0x1f << MVEBU_SPI_A3700_CLK_PRESCALE_BIT)
+#define MVEBU_SPI_A3700_CLK_PRESCALE_MASK	0x1f
+
 
 /* SPI registers */
 struct spi_reg {
@@ -35,8 +35,7 @@ struct spi_reg {
 
 struct mvebu_spi_platdata {
 	struct spi_reg *spireg;
-	unsigned int frequency;
-	unsigned int clock;
+	struct clk clk;
 };
 
 static void spi_cs_activate(struct spi_reg *reg, int cs)
@@ -177,17 +176,18 @@ static int mvebu_spi_set_speed(struct udevice *bus, uint hz)
 {
 	struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
 	struct spi_reg *reg = plat->spireg;
-	u32 data;
+	u32 data, prescale;
 
 	data = readl(&reg->cfg);
 
-	/* Set Prescaler */
-	data &= ~MVEBU_SPI_A3700_CLK_PRESCALE_MASK;
+	prescale = DIV_ROUND_UP(clk_get_rate(&plat->clk), hz);
+	if (prescale > 0x1f)
+		prescale = 0x1f;
+	else if (prescale > 0xf)
+		prescale = 0x10 + (prescale + 1) / 2;
 
-	/* Calculate Prescaler = (spi_input_freq / spi_max_freq) */
-	if (hz > plat->frequency)
-		hz = plat->frequency;
-	data |= plat->clock / hz;
+	data &= ~MVEBU_SPI_A3700_CLK_PRESCALE_MASK;
+	data |= prescale & MVEBU_SPI_A3700_CLK_PRESCALE_MASK;
 
 	writel(data, &reg->cfg);
 
@@ -251,21 +251,24 @@ static int mvebu_spi_probe(struct udevice *bus)
 static int mvebu_spi_ofdata_to_platdata(struct udevice *bus)
 {
 	struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
+	int ret;
 
 	plat->spireg = (struct spi_reg *)devfdt_get_addr(bus);
 
-	/*
-	 * FIXME
-	 * Right now, mvebu does not have a clock infrastructure in U-Boot
-	 * which should be used to query the input clock to the SPI
-	 * controller. Once this clock driver is integrated into U-Boot
-	 * it should be used to read the input clock and the DT property
-	 * can be removed.
-	 */
-	plat->clock = fdtdec_get_int(gd->fdt_blob, dev_of_offset(bus),
-				     "clock-frequency", 160000);
-	plat->frequency = fdtdec_get_int(gd->fdt_blob, dev_of_offset(bus),
-					 "spi-max-frequency", 40000);
+	ret = clk_get_by_index(bus, 0, &plat->clk);
+	if (ret) {
+		dev_err(bus, "cannot get clock\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int mvebu_spi_remove(struct udevice *bus)
+{
+	struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
+
+	clk_free(&plat->clk);
 
 	return 0;
 }
@@ -293,4 +296,5 @@ U_BOOT_DRIVER(mvebu_spi) = {
 	.ofdata_to_platdata = mvebu_spi_ofdata_to_platdata,
 	.platdata_auto_alloc_size = sizeof(struct mvebu_spi_platdata),
 	.probe = mvebu_spi_probe,
+	.remove = mvebu_spi_remove,
 };