Staging: fbtft: Switch to the gpio descriptor interface

This switches the fbtft driver to use GPIO descriptors
rather than numerical gpios:

Utilize the GPIO library's intrinsic handling of OF GPIOs
and polarity. If the line is flagged active low, gpiolib
will deal with this.

Remove gpios from platform device structure. Neither assign
statically numbers to gpios in platform device nor allow
gpios to be parsed as module parameters.

Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 29 insertions, 144 deletions

diff --git a/drivers/staging/fbtft/fbtft-core.c b/drivers/staging/fbtft/fbtft-core.c
index a2df02d97a8e..de3f431abc15 100644
--- a/drivers/staging/fbtft/fbtft-core.c
+++ b/drivers/staging/fbtft/fbtft-core.c
@@ -16,7 +16,7 @@
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/fb.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/spi/spi.h>
 #include <linux/delay.h>
 #include <linux/uaccess.h>
@@ -24,7 +24,6 @@
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>
 #include <linux/of.h>
-#include <linux/of_gpio.h>
 #include <video/mipi_display.h>
 
 #include "fbtft.h"
@@ -38,8 +37,8 @@ int fbtft_write_buf_dc(struct fbtft_par *par, void *buf, size_t len, int dc)
 {
 	int ret;
 
-	if (gpio_is_valid(par->gpio.dc))
-		gpio_set_value(par->gpio.dc, dc);
+	if (par->gpio.dc)
+		gpiod_set_value(par->gpio.dc, dc);
 
 	ret = par->fbtftops.write(par, buf, len);
 	if (ret < 0)
@@ -71,127 +70,27 @@ void fbtft_dbg_hex(const struct device *dev, int groupsize,
 }
 EXPORT_SYMBOL(fbtft_dbg_hex);
 
-static unsigned long fbtft_request_gpios_match(struct fbtft_par *par,
-					       const struct fbtft_gpio *gpio)
-{
-	int ret;
-	unsigned int val;
-
-	fbtft_par_dbg(DEBUG_REQUEST_GPIOS_MATCH, par, "%s('%s')\n",
-		      __func__, gpio->name);
-
-	if (strcasecmp(gpio->name, "reset") == 0) {
-		par->gpio.reset = gpio->gpio;
-		return GPIOF_OUT_INIT_HIGH;
-	} else if (strcasecmp(gpio->name, "dc") == 0) {
-		par->gpio.dc = gpio->gpio;
-		return GPIOF_OUT_INIT_LOW;
-	} else if (strcasecmp(gpio->name, "cs") == 0) {
-		par->gpio.cs = gpio->gpio;
-		return GPIOF_OUT_INIT_HIGH;
-	} else if (strcasecmp(gpio->name, "wr") == 0) {
-		par->gpio.wr = gpio->gpio;
-		return GPIOF_OUT_INIT_HIGH;
-	} else if (strcasecmp(gpio->name, "rd") == 0) {
-		par->gpio.rd = gpio->gpio;
-		return GPIOF_OUT_INIT_HIGH;
-	} else if (strcasecmp(gpio->name, "latch") == 0) {
-		par->gpio.latch = gpio->gpio;
-		return GPIOF_OUT_INIT_LOW;
-	} else if (gpio->name[0] == 'd' && gpio->name[1] == 'b') {
-		ret = kstrtouint(&gpio->name[2], 10, &val);
-		if (ret == 0 && val < 16) {
-			par->gpio.db[val] = gpio->gpio;
-			return GPIOF_OUT_INIT_LOW;
-		}
-	} else if (strcasecmp(gpio->name, "led") == 0) {
-		par->gpio.led[0] = gpio->gpio;
-		return GPIOF_OUT_INIT_LOW;
-	} else if (strcasecmp(gpio->name, "led_") == 0) {
-		par->gpio.led[0] = gpio->gpio;
-		return GPIOF_OUT_INIT_HIGH;
-	}
-
-	return FBTFT_GPIO_NO_MATCH;
-}
-
-static int fbtft_request_gpios(struct fbtft_par *par)
-{
-	struct fbtft_platform_data *pdata = par->pdata;
-	const struct fbtft_gpio *gpio;
-	unsigned long flags;
-	int ret;
-
-	if (!(pdata && pdata->gpios))
-		return 0;
-
-	gpio = pdata->gpios;
-	while (gpio->name[0]) {
-		flags = FBTFT_GPIO_NO_MATCH;
-		/* if driver provides match function, try it first,
-		 * if no match use our own
-		 */
-		if (par->fbtftops.request_gpios_match)
-			flags = par->fbtftops.request_gpios_match(par, gpio);
-		if (flags == FBTFT_GPIO_NO_MATCH)
-			flags = fbtft_request_gpios_match(par, gpio);
-		if (flags != FBTFT_GPIO_NO_MATCH) {
-			ret = devm_gpio_request_one(par->info->device,
-					      gpio->gpio, flags,
-					      par->info->device->driver->name);
-			if (ret < 0) {
-				dev_err(par->info->device,
-					"%s: gpio_request_one('%s'=%d) failed with %d\n",
-					__func__, gpio->name,
-					gpio->gpio, ret);
-				return ret;
-			}
-			fbtft_par_dbg(DEBUG_REQUEST_GPIOS, par,
-				      "%s: '%s' = GPIO%d\n",
-				      __func__, gpio->name, gpio->gpio);
-		}
-		gpio++;
-	}
-
-	return 0;
-}
-
 #ifdef CONFIG_OF
 static int fbtft_request_one_gpio(struct fbtft_par *par,
-				  const char *name, int index, int *gpiop)
+				  const char *name, int index,
+				  struct gpio_desc **gpiop)
 {
 	struct device *dev = par->info->device;
 	struct device_node *node = dev->of_node;
-	int gpio, flags, ret = 0;
-	enum of_gpio_flags of_flags;
+	int ret = 0;
 
 	if (of_find_property(node, name, NULL)) {
-		gpio = of_get_named_gpio_flags(node, name, index, &of_flags);
-		if (gpio == -ENOENT)
-			return 0;
-		if (gpio == -EPROBE_DEFER)
-			return gpio;
-		if (gpio < 0) {
+		*gpiop = devm_gpiod_get_index(dev, dev->driver->name, index,
+					      GPIOD_OUT_HIGH);
+		if (IS_ERR(*gpiop)) {
+			ret = PTR_ERR(*gpiop);
 			dev_err(dev,
-				"failed to get '%s' from DT\n", name);
-			return gpio;
-		}
-
-		/* active low translates to initially low */
-		flags = (of_flags & OF_GPIO_ACTIVE_LOW) ? GPIOF_OUT_INIT_LOW :
-							GPIOF_OUT_INIT_HIGH;
-		ret = devm_gpio_request_one(dev, gpio, flags,
-					    dev->driver->name);
-		if (ret) {
-			dev_err(dev,
-				"gpio_request_one('%s'=%d) failed with %d\n",
-				name, gpio, ret);
+				"Failed to request %s GPIO:%d\n", name, ret);
 			return ret;
+
 		}
-		if (gpiop)
-			*gpiop = gpio;
-		fbtft_par_dbg(DEBUG_REQUEST_GPIOS, par, "%s: '%s' = GPIO%d\n",
-			      __func__, name, gpio);
+		fbtft_par_dbg(DEBUG_REQUEST_GPIOS, par, "%s: '%s' GPIO\n",
+			      __func__, name);
 	}
 
 	return ret;
@@ -254,9 +153,9 @@ static int fbtft_backlight_update_status(struct backlight_device *bd)
 
 	if ((bd->props.power == FB_BLANK_UNBLANK) &&
 	    (bd->props.fb_blank == FB_BLANK_UNBLANK))
-		gpio_set_value(par->gpio.led[0], polarity);
+		gpiod_set_value(par->gpio.led[0], polarity);
 	else
-		gpio_set_value(par->gpio.led[0], !polarity);
+		gpiod_set_value(par->gpio.led[0], !polarity);
 
 	return 0;
 }
@@ -286,7 +185,7 @@ void fbtft_register_backlight(struct fbtft_par *par)
 	struct backlight_device *bd;
 	struct backlight_properties bl_props = { 0, };
 
-	if (par->gpio.led[0] == -1) {
+	if (!par->gpio.led[0]) {
 		fbtft_par_dbg(DEBUG_BACKLIGHT, par,
 			      "%s(): led pin not set, exiting.\n", __func__);
 		return;
@@ -295,7 +194,7 @@ void fbtft_register_backlight(struct fbtft_par *par)
 	bl_props.type = BACKLIGHT_RAW;
 	/* Assume backlight is off, get polarity from current state of pin */
 	bl_props.power = FB_BLANK_POWERDOWN;
-	if (!gpio_get_value(par->gpio.led[0]))
+	if (!gpiod_get_value(par->gpio.led[0]))
 		par->polarity = true;
 
 	bd = backlight_device_register(dev_driver_string(par->info->device),
@@ -333,12 +232,12 @@ static void fbtft_set_addr_win(struct fbtft_par *par, int xs, int ys, int xe,
 
 static void fbtft_reset(struct fbtft_par *par)
 {
-	if (par->gpio.reset == -1)
+	if (!par->gpio.reset)
 		return;
 	fbtft_par_dbg(DEBUG_RESET, par, "%s()\n", __func__);
-	gpio_set_value_cansleep(par->gpio.reset, 0);
+	gpiod_set_value_cansleep(par->gpio.reset, 0);
 	usleep_range(20, 40);
-	gpio_set_value_cansleep(par->gpio.reset, 1);
+	gpiod_set_value_cansleep(par->gpio.reset, 1);
 	msleep(120);
 }
 
@@ -663,7 +562,7 @@ struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
 	int txbuflen = display->txbuflen;
 	unsigned int bpp = display->bpp;
 	unsigned int fps = display->fps;
-	int vmem_size, i;
+	int vmem_size;
 	const s16 *init_sequence = display->init_sequence;
 	char *gamma = display->gamma;
 	u32 *gamma_curves = NULL;
@@ -841,19 +740,6 @@ struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
 		par->txbuf.len = txbuflen;
 	}
 
-	/* Initialize gpios to disabled */
-	par->gpio.reset = -1;
-	par->gpio.dc = -1;
-	par->gpio.rd = -1;
-	par->gpio.wr = -1;
-	par->gpio.cs = -1;
-	par->gpio.latch = -1;
-	for (i = 0; i < 16; i++) {
-		par->gpio.db[i] = -1;
-		par->gpio.led[i] = -1;
-		par->gpio.aux[i] = -1;
-	}
-
 	/* default fbtft operations */
 	par->fbtftops.write = fbtft_write_spi;
 	par->fbtftops.read = fbtft_read_spi;
@@ -863,7 +749,6 @@ struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
 	par->fbtftops.reset = fbtft_reset;
 	par->fbtftops.mkdirty = fbtft_mkdirty;
 	par->fbtftops.update_display = fbtft_update_display;
-	par->fbtftops.request_gpios = fbtft_request_gpios;
 	if (display->backlight)
 		par->fbtftops.register_backlight = fbtft_register_backlight;
 
@@ -1035,8 +920,8 @@ static int fbtft_init_display_dt(struct fbtft_par *par)
 		return -EINVAL;
 
 	par->fbtftops.reset(par);
-	if (par->gpio.cs != -1)
-		gpio_set_value(par->gpio.cs, 0);  /* Activate chip */
+	if (!par->gpio.cs)
+		gpiod_set_value(par->gpio.cs, 0);  /* Activate chip */
 
 	while (p) {
 		if (val & FBTFT_OF_INIT_CMD) {
@@ -1126,8 +1011,8 @@ int fbtft_init_display(struct fbtft_par *par)
 	}
 
 	par->fbtftops.reset(par);
-	if (par->gpio.cs != -1)
-		gpio_set_value(par->gpio.cs, 0);  /* Activate chip */
+	if (!par->gpio.cs)
+		gpiod_set_value(par->gpio.cs, 0);  /* Activate chip */
 
 	i = 0;
 	while (i < FBTFT_MAX_INIT_SEQUENCE) {
@@ -1227,7 +1112,7 @@ static int fbtft_verify_gpios(struct fbtft_par *par)
 	fbtft_par_dbg(DEBUG_VERIFY_GPIOS, par, "%s()\n", __func__);
 
 	if (pdata->display.buswidth != 9 &&  par->startbyte == 0 &&
-	    par->gpio.dc < 0) {
+	    !par->gpio.dc) {
 		dev_err(par->info->device,
 			"Missing info about 'dc' gpio. Aborting.\n");
 		return -EINVAL;
@@ -1236,12 +1121,12 @@ static int fbtft_verify_gpios(struct fbtft_par *par)
 	if (!par->pdev)
 		return 0;
 
-	if (par->gpio.wr < 0) {
+	if (!par->gpio.wr) {
 		dev_err(par->info->device, "Missing 'wr' gpio. Aborting.\n");
 		return -EINVAL;
 	}
 	for (i = 0; i < pdata->display.buswidth; i++) {
-		if (par->gpio.db[i] < 0) {
+		if (!par->gpio.db[i]) {
 			dev_err(par->info->device,
 				"Missing 'db%02d' gpio. Aborting.\n", i);
 			return -EINVAL;