spi: mxc_spi: support driver model

Add driver model support for mxc spi driver.
Most functions are restructured to be reused by DM and non-DM.
Tested on mx6slevk/mx6qsabresd board.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>
Reviewed-by: Stefano Babic <sbabic@denx.de>

drivers/spi/mxc_spi.c

@@ -5,6 +5,7 @@
  */
 
 #include <common.h>
+#include <dm.h>
 #include <malloc.h>
 #include <spi.h>
 #include <linux/errno.h>
@@ -14,6 +15,8 @@
 #include <asm/arch/clock.h>
 #include <asm/mach-imx/spi.h>
 
+DECLARE_GLOBAL_DATA_PTR;
+
 #ifdef CONFIG_MX27
 /* i.MX27 has a completely wrong register layout and register definitions in the
  * datasheet, the correct one is in the Freescale's Linux driver */
@@ -22,10 +25,6 @@
 "See linux mxc_spi driver from Freescale for details."
 #endif
 
-static unsigned long spi_bases[] = {
-	MXC_SPI_BASE_ADDRESSES
-};
-
 __weak int board_spi_cs_gpio(unsigned bus, unsigned cs)
 {
 	return -1;
@@ -51,6 +50,7 @@ struct mxc_spi_slave {
 	int		ss_pol;
 	unsigned int	max_hz;
 	unsigned int	mode;
+	struct gpio_desc ss;
 };
 
 static inline struct mxc_spi_slave *to_mxc_spi_slave(struct spi_slave *slave)
@@ -58,19 +58,24 @@ static inline struct mxc_spi_slave *to_mxc_spi_slave(struct spi_slave *slave)
 	return container_of(slave, struct mxc_spi_slave, slave);
 }
 
-void spi_cs_activate(struct spi_slave *slave)
+static void mxc_spi_cs_activate(struct mxc_spi_slave *mxcs)
 {
-	struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
-	if (mxcs->gpio > 0)
-		gpio_set_value(mxcs->gpio, mxcs->ss_pol);
+	if (CONFIG_IS_ENABLED(DM_SPI)) {
+		dm_gpio_set_value(&mxcs->ss, mxcs->ss_pol);
+	} else {
+		if (mxcs->gpio > 0)
+			gpio_set_value(mxcs->gpio, mxcs->ss_pol);
+	}
 }
 
-void spi_cs_deactivate(struct spi_slave *slave)
+static void mxc_spi_cs_deactivate(struct mxc_spi_slave *mxcs)
 {
-	struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
-	if (mxcs->gpio > 0)
-		gpio_set_value(mxcs->gpio,
-			      !(mxcs->ss_pol));
+	if (CONFIG_IS_ENABLED(DM_SPI)) {
+		dm_gpio_set_value(&mxcs->ss, !(mxcs->ss_pol));
+	} else {
+		if (mxcs->gpio > 0)
+			gpio_set_value(mxcs->gpio, !(mxcs->ss_pol));
+	}
 }
 
 u32 get_cspi_div(u32 div)
@@ -211,10 +216,9 @@ static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs)
 }
 #endif
 
-int spi_xchg_single(struct spi_slave *slave, unsigned int bitlen,
+int spi_xchg_single(struct mxc_spi_slave *mxcs, unsigned int bitlen,
 	const u8 *dout, u8 *din, unsigned long flags)
 {
-	struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
 	int nbytes = DIV_ROUND_UP(bitlen, 8);
 	u32 data, cnt, i;
 	struct cspi_regs *regs = (struct cspi_regs *)mxcs->base;
@@ -327,8 +331,9 @@ int spi_xchg_single(struct spi_slave *slave, unsigned int bitlen,
 
 }
 
-int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
-		void *din, unsigned long flags)
+static int mxc_spi_xfer_internal(struct mxc_spi_slave *mxcs,
+				 unsigned int bitlen, const void *dout,
+				 void *din, unsigned long flags)
 {
 	int n_bytes = DIV_ROUND_UP(bitlen, 8);
 	int n_bits;
@@ -337,11 +342,11 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
 	u8 *p_outbuf = (u8 *)dout;
 	u8 *p_inbuf = (u8 *)din;
 
-	if (!slave)
-		return -1;
+	if (!mxcs)
+		return -EINVAL;
 
 	if (flags & SPI_XFER_BEGIN)
-		spi_cs_activate(slave);
+		mxc_spi_cs_activate(mxcs);
 
 	while (n_bytes > 0) {
 		if (n_bytes < MAX_SPI_BYTES)
@@ -351,7 +356,7 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
 
 		n_bits = blk_size * 8;
 
-		ret = spi_xchg_single(slave, n_bits, p_outbuf, p_inbuf, 0);
+		ret = spi_xchg_single(mxcs, n_bits, p_outbuf, p_inbuf, 0);
 
 		if (ret)
 			return ret;
@@ -363,12 +368,39 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
 	}
 
 	if (flags & SPI_XFER_END) {
-		spi_cs_deactivate(slave);
+		mxc_spi_cs_deactivate(mxcs);
 	}
 
 	return 0;
 }
 
+static int mxc_spi_claim_bus_internal(struct mxc_spi_slave *mxcs, int cs)
+{
+	struct cspi_regs *regs = (struct cspi_regs *)mxcs->base;
+	int ret;
+
+	reg_write(&regs->rxdata, 1);
+	udelay(1);
+	ret = spi_cfg_mxc(mxcs, cs);
+	if (ret) {
+		printf("mxc_spi: cannot setup SPI controller\n");
+		return ret;
+	}
+	reg_write(&regs->period, MXC_CSPIPERIOD_32KHZ);
+	reg_write(&regs->intr, 0);
+
+	return 0;
+}
+
+#ifndef CONFIG_DM_SPI
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
+		void *din, unsigned long flags)
+{
+	struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
+
+	return mxc_spi_xfer_internal(mxcs, bitlen, dout, din, flags);
+}
+
 void spi_init(void)
 {
 }
@@ -390,6 +422,7 @@ static int setup_cs_gpio(struct mxc_spi_slave *mxcs,
 	if (mxcs->gpio == -1)
 		return 0;
 
+	gpio_request(mxcs->gpio, "spi-cs");
 	ret = gpio_direction_output(mxcs->gpio, !(mxcs->ss_pol));
 	if (ret) {
 		printf("mxc_spi: cannot setup gpio %d\n", mxcs->gpio);
@@ -399,6 +432,10 @@ static int setup_cs_gpio(struct mxc_spi_slave *mxcs,
 	return 0;
 }
 
+static unsigned long spi_bases[] = {
+	MXC_SPI_BASE_ADDRESSES
+};
+
 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 			unsigned int max_hz, unsigned int mode)
 {
@@ -443,24 +480,104 @@ void spi_free_slave(struct spi_slave *slave)
 
 int spi_claim_bus(struct spi_slave *slave)
 {
-	int ret;
 	struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
-	struct cspi_regs *regs = (struct cspi_regs *)mxcs->base;
 
-	reg_write(&regs->rxdata, 1);
-	udelay(1);
-	ret = spi_cfg_mxc(mxcs, slave->cs);
+	return mxc_spi_claim_bus_internal(mxcs, slave->cs);
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+	/* TODO: Shut the controller down */
+}
+#else
+
+static int mxc_spi_probe(struct udevice *bus)
+{
+	struct mxc_spi_slave *plat = bus->platdata;
+	struct mxc_spi_slave *mxcs = dev_get_platdata(bus);
+	int node = dev_of_offset(bus);
+	const void *blob = gd->fdt_blob;
+	int ret;
+
+	if (gpio_request_by_name(bus, "cs-gpios", 0, &plat->ss,
+				 GPIOD_IS_OUT)) {
+		dev_err(bus, "No cs-gpios property\n");
+		return -EINVAL;
+	}
+
+	plat->base = dev_get_addr(bus);
+	if (plat->base == FDT_ADDR_T_NONE)
+		return -ENODEV;
+
+	ret = dm_gpio_set_value(&plat->ss, !(mxcs->ss_pol));
 	if (ret) {
-		printf("mxc_spi: cannot setup SPI controller\n");
+		dev_err(bus, "Setting cs error\n");
 		return ret;
 	}
-	reg_write(&regs->period, MXC_CSPIPERIOD_32KHZ);
-	reg_write(&regs->intr, 0);
+
+	mxcs->max_hz = fdtdec_get_int(blob, node, "spi-max-frequency",
+				      20000000);
 
 	return 0;
 }
 
-void spi_release_bus(struct spi_slave *slave)
+static int mxc_spi_xfer(struct udevice *dev, unsigned int bitlen,
+		const void *dout, void *din, unsigned long flags)
 {
-	/* TODO: Shut the controller down */
+	struct mxc_spi_slave *mxcs = dev_get_platdata(dev->parent);
+
+
+	return mxc_spi_xfer_internal(mxcs, bitlen, dout, din, flags);
+}
+
+static int mxc_spi_claim_bus(struct udevice *dev)
+{
+	struct mxc_spi_slave *mxcs = dev_get_platdata(dev->parent);
+	struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
+
+	return mxc_spi_claim_bus_internal(mxcs, slave_plat->cs);
 }
+
+static int mxc_spi_release_bus(struct udevice *dev)
+{
+	return 0;
+}
+
+static int mxc_spi_set_speed(struct udevice *bus, uint speed)
+{
+	/* Nothing to do */
+	return 0;
+}
+
+static int mxc_spi_set_mode(struct udevice *bus, uint mode)
+{
+	struct mxc_spi_slave *mxcs = dev_get_platdata(bus);
+
+	mxcs->mode = mode;
+	mxcs->ss_pol = (mode & SPI_CS_HIGH) ? 1 : 0;
+
+	return 0;
+}
+
+static const struct dm_spi_ops mxc_spi_ops = {
+	.claim_bus	= mxc_spi_claim_bus,
+	.release_bus	= mxc_spi_release_bus,
+	.xfer		= mxc_spi_xfer,
+	.set_speed	= mxc_spi_set_speed,
+	.set_mode	= mxc_spi_set_mode,
+};
+
+static const struct udevice_id mxc_spi_ids[] = {
+	{ .compatible = "fsl,imx51-ecspi" },
+	{ }
+};
+
+U_BOOT_DRIVER(mxc_spi) = {
+	.name	= "mxc_spi",
+	.id	= UCLASS_SPI,
+	.of_match = mxc_spi_ids,
+	.ops	= &mxc_spi_ops,
+	.platdata_auto_alloc_size = sizeof(struct mxc_spi_slave),
+	.probe	= mxc_spi_probe,
+};
+#endif