[U-Boot] [PATCH v2] dm:gpio:mxc add DT support

[Peng Fan]

This patch add DT support for mxc gpio driver.

Include a bank_index entry in platdata. This can avoid using
`plat - mxc_plat` to calculate bank number. Also this can simplify code.

There are two places still using CONFIG_OF_CONTROL macro, just to
shrink code size if only support DM but not support DT.
1. The U_BOOT_DEVICES and mxc_plat array are complied out. To DT,
   platdata is alloced using calloc, so there is no need to use mxc_plat.
2. add a function mxc_get_gpio_addr to get "reg" property if DT support.
   If no DT, this function just returns NULL.

The following situations are tested:
1. with DM, without DT
2. with DM and DT
3. without DM
Since device tree has not been upstreamed, if want to test this patch.
The followings need to be done.
 + pieces of code does not gpio_request when using gpio_direction_xxx and
   etc, need to request gpio.
 + move the gpio settings from board_early_init_f to board_init
 + define CONFIG_DM ,CONFIG_DM_GPIO and CONFIG_OF_CONTROL
 + Add device tree file and do related configuration in
   `make ARCH=arm menuconfig`
These will be done in future patches by step.

Signed-off-by: Peng Fan <Peng.Fan at freescale.com>
---

Changes v2:
 1. remove uneccessary #ifdef
 2. add more stuff in commit log
 3. include a new function mxc_get_gpio_addr to get register base.
    This function is different for DT and not DT, by `#ifdef`.
    If using one implementation for DT and not DT, final image will be big.
 4. include a new entry in platdata, named bank_index. it can simplify DT
    support. To no DT, bank_index is static initilized; to DT, bank_index
    is get from device's req_seq.

 drivers/gpio/mxc_gpio.c | 89 +++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 71 insertions(+), 18 deletions(-)

diff --git a/drivers/gpio/mxc_gpio.c b/drivers/gpio/mxc_gpio.c
index 8bb9e39..5826620 100644
--- a/drivers/gpio/mxc_gpio.c
+++ b/drivers/gpio/mxc_gpio.c
@@ -23,6 +23,7 @@ enum mxc_gpio_direction {
 #define GPIO_PER_BANK			32
 
 struct mxc_gpio_plat {
+	int bank_index;
 	struct gpio_regs *regs;
 };
 
@@ -150,6 +151,9 @@ int gpio_direction_output(unsigned gpio, int value)
 #endif
 
 #ifdef CONFIG_DM_GPIO
+#include <fdtdec.h>
+DECLARE_GLOBAL_DATA_PTR;
+
 static int mxc_gpio_is_output(struct gpio_regs *regs, int offset)
 {
 	u32 val;
@@ -258,23 +262,6 @@ static const struct dm_gpio_ops gpio_mxc_ops = {
 	.get_function		= mxc_gpio_get_function,
 };
 
-static const struct mxc_gpio_plat mxc_plat[] = {
-	{ (struct gpio_regs *)GPIO1_BASE_ADDR },
-	{ (struct gpio_regs *)GPIO2_BASE_ADDR },
-	{ (struct gpio_regs *)GPIO3_BASE_ADDR },
-#if defined(CONFIG_MX25) || defined(CONFIG_MX27) || defined(CONFIG_MX51) || \
-		defined(CONFIG_MX53) || defined(CONFIG_MX6)
-	{ (struct gpio_regs *)GPIO4_BASE_ADDR },
-#endif
-#if defined(CONFIG_MX27) || defined(CONFIG_MX53) || defined(CONFIG_MX6)
-	{ (struct gpio_regs *)GPIO5_BASE_ADDR },
-	{ (struct gpio_regs *)GPIO6_BASE_ADDR },
-#endif
-#if defined(CONFIG_MX53) || defined(CONFIG_MX6)
-	{ (struct gpio_regs *)GPIO7_BASE_ADDR },
-#endif
-};
-
 static int mxc_gpio_probe(struct udevice *dev)
 {
 	struct mxc_bank_info *bank = dev_get_priv(dev);
@@ -283,7 +270,7 @@ static int mxc_gpio_probe(struct udevice *dev)
 	int banknum;
 	char name[18], *str;
 
-	banknum = plat - mxc_plat;
+	banknum = plat->bank_index;
 	sprintf(name, "GPIO%d_", banknum + 1);
 	str = strdup(name);
 	if (!str)
@@ -295,12 +282,77 @@ static int mxc_gpio_probe(struct udevice *dev)
 	return 0;
 }
 
+#ifdef CONFIG_OF_CONTROL
+static struct gpio_regs *mxc_get_gpio_addr(struct udevice *device)
+{
+	fdt_addr_t addr;
+	addr = fdtdec_get_addr(gd->fdt_blob, device->of_offset, "reg");
+	if (addr == FDT_ADDR_T_NONE)
+		return NULL;
+	else
+		return (struct gpio_regs *)addr;
+}
+#else
+static struct gpio_regs *mxc_get_gpio_addr(struct udevice *device)
+{
+	return NULL;
+}
+#endif
+
+static int mxc_gpio_bind(struct udevice *device)
+{
+	struct mxc_gpio_plat *plat = device->platdata;
+	struct gpio_regs *regs;
+
+	if (plat)
+		return 0;
+
+	regs = mxc_get_gpio_addr(device);
+	if (!regs)
+		return -ENXIO;
+
+	plat = calloc(1, sizeof(*plat));
+	if (!plat)
+		return -ENOMEM;
+
+	plat->regs = regs;
+	plat->bank_index = device->req_seq;
+	device->platdata = plat;
+
+	return 0;
+}
+
+static const struct udevice_id mxc_gpio_ids[] = {
+	{ .compatible = "fsl,imx35-gpio" },
+	{ }
+};
+
 U_BOOT_DRIVER(gpio_mxc) = {
 	.name	= "gpio_mxc",
 	.id	= UCLASS_GPIO,
 	.ops	= &gpio_mxc_ops,
 	.probe	= mxc_gpio_probe,
 	.priv_auto_alloc_size = sizeof(struct mxc_bank_info),
+	.of_match = mxc_gpio_ids,
+	.bind	= mxc_gpio_bind,
+};
+
+#ifndef CONFIG_OF_CONTROL
+static const struct mxc_gpio_plat mxc_plat[] = {
+	{ 0, (struct gpio_regs *)GPIO1_BASE_ADDR },
+	{ 1, (struct gpio_regs *)GPIO2_BASE_ADDR },
+	{ 2, (struct gpio_regs *)GPIO3_BASE_ADDR },
+#if defined(CONFIG_MX25) || defined(CONFIG_MX27) || defined(CONFIG_MX51) || \
+		defined(CONFIG_MX53) || defined(CONFIG_MX6)
+	{ 3, (struct gpio_regs *)GPIO4_BASE_ADDR },
+#endif
+#if defined(CONFIG_MX27) || defined(CONFIG_MX53) || defined(CONFIG_MX6)
+	{ 4, (struct gpio_regs *)GPIO5_BASE_ADDR },
+	{ 5, (struct gpio_regs *)GPIO6_BASE_ADDR },
+#endif
+#if defined(CONFIG_MX53) || defined(CONFIG_MX6)
+	{ 6, (struct gpio_regs *)GPIO7_BASE_ADDR },
+#endif
 };
 
 U_BOOT_DEVICES(mxc_gpios) = {
@@ -320,3 +372,4 @@ U_BOOT_DEVICES(mxc_gpios) = {
 #endif
 };
 #endif
+#endif
-- 
1.8.4