linux-kernel - [PATCH 2/4] fbdev/ARM: Fix up LCD MIPID GPIO usage

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Date:   Sun, 30 Apr 2023 11:22:17 +0200
From:   Linus Walleij <linus.walleij@...aro.org>
To:     Aaro Koskinen <aaro.koskinen@....fi>,
        Janusz Krzysztofik <jmkrzyszt@...il.com>,
        Tony Lindgren <tony@...mide.com>,
        Russell King <linux@...linux.org.uk>,
        Daniel Mack <daniel@...que.org>,
        Haojian Zhuang <haojian.zhuang@...il.com>,
        Robert Jarzmik <robert.jarzmik@...e.fr>,
        Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Mark Brown <broonie@...nel.org>,
        Bartosz Golaszewski <bartosz.golaszewski@...aro.org>,
        Andreas Kemnade <andreas@...nade.info>,
        Helge Deller <deller@....de>,
        Ulf Hansson <ulf.hansson@...aro.org>
Cc:     linux-omap@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, linux-mips@...r.kernel.org,
        linux-input@...r.kernel.org, linux-spi@...r.kernel.org,
        linux-fbdev@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        linux-mmc@...r.kernel.org, Linus Walleij <linus.walleij@...aro.org>
Subject: [PATCH 2/4] fbdev/ARM: Fix up LCD MIPID GPIO usage

The Nokia 770 is using GPIOs from the global numberspace to pass
down to the LCD controller. This regresses when we let the OMAP
GPIO driver use dynamic GPIO base.

As this is the only user of LCD MIPID we can easily augment the
driver to use a GPIO descriptor instead and resolve the issue.

The platform data .shutdown() callback wasn't even used in the
code, but we encode a shutdown asserting RESET in the remove()
callback for completeness sake.

Fixes: 92bf78b33b0b ("gpio: omap: use dynamic allocation of base")
Signed-off-by: Linus Walleij <linus.walleij@...aro.org>
---
 arch/arm/mach-omap1/board-nokia770.c    | 23 ++++++++++-------------
 drivers/video/fbdev/omap/lcd_mipid.c    | 10 ++++++++++
 include/linux/platform_data/lcd-mipid.h |  2 --
 3 files changed, 20 insertions(+), 15 deletions(-)

diff --git a/arch/arm/mach-omap1/board-nokia770.c b/arch/arm/mach-omap1/board-nokia770.c
index eb7652670447..509afcd42823 100644
--- a/arch/arm/mach-omap1/board-nokia770.c
+++ b/arch/arm/mach-omap1/board-nokia770.c
@@ -85,26 +85,23 @@ static struct platform_device *nokia770_devices[] __initdata = {
 	&nokia770_kp_device,
 };
 
-static void mipid_shutdown(struct mipid_platform_data *pdata)
-{
-	if (pdata->nreset_gpio != -1) {
-		printk(KERN_INFO "shutdown LCD\n");
-		gpio_set_value(pdata->nreset_gpio, 0);
-		msleep(120);
-	}
-}
-
-static struct mipid_platform_data nokia770_mipid_platform_data = {
-	.shutdown = mipid_shutdown,
-};
+static struct mipid_platform_data nokia770_mipid_platform_data = { };
 
 static const struct omap_lcd_config nokia770_lcd_config __initconst = {
 	.ctrl_name	= "hwa742",
 };
 
+static struct gpiod_lookup_table nokia770_lcd_gpio_table = {
+	.dev_id = "lcd_mipid",
+	.table = {
+		GPIO_LOOKUP("gpio-0-15", 13, "reset", GPIO_ACTIVE_LOW),
+		{ }
+	},
+};
+
 static void __init mipid_dev_init(void)
 {
-	nokia770_mipid_platform_data.nreset_gpio = 13;
+	gpiod_add_lookup_table(&nokia770_lcd_gpio_table);
 	nokia770_mipid_platform_data.data_lines = 16;
 
 	omapfb_set_lcd_config(&nokia770_lcd_config);
diff --git a/drivers/video/fbdev/omap/lcd_mipid.c b/drivers/video/fbdev/omap/lcd_mipid.c
index 03cff39d392d..e4a7f0b824ff 100644
--- a/drivers/video/fbdev/omap/lcd_mipid.c
+++ b/drivers/video/fbdev/omap/lcd_mipid.c
@@ -7,6 +7,7 @@
  */
 #include <linux/device.h>
 #include <linux/delay.h>
+#include <linux/gpio/consumer.h>
 #include <linux/slab.h>
 #include <linux/workqueue.h>
 #include <linux/spi/spi.h>
@@ -41,6 +42,7 @@ struct mipid_device {
 						   when we can issue the
 						   next sleep in/out command */
 	unsigned long	hw_guard_wait;		/* max guard time in jiffies */
+	struct gpio_desc	*reset;
 
 	struct omapfb_device	*fbdev;
 	struct spi_device	*spi;
@@ -556,6 +558,12 @@ static int mipid_spi_probe(struct spi_device *spi)
 		return -ENOMEM;
 	}
 
+	/* This will de-assert RESET if active */
+	md->reset = gpiod_get(&spi->dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(md->reset))
+		return dev_err_probe(&spi->dev, PTR_ERR(md->reset),
+				     "no reset GPIO line\n");
+
 	spi->mode = SPI_MODE_0;
 	md->spi = spi;
 	dev_set_drvdata(&spi->dev, md);
@@ -574,6 +582,8 @@ static void mipid_spi_remove(struct spi_device *spi)
 {
 	struct mipid_device *md = dev_get_drvdata(&spi->dev);
 
+	/* Asserts RESET */
+	gpiod_set_value(md->reset, 1);
 	mipid_disable(&md->panel);
 	kfree(md);
 }
diff --git a/include/linux/platform_data/lcd-mipid.h b/include/linux/platform_data/lcd-mipid.h
index 63f05eb23827..4927cfc5158c 100644
--- a/include/linux/platform_data/lcd-mipid.h
+++ b/include/linux/platform_data/lcd-mipid.h
@@ -15,10 +15,8 @@ enum mipid_test_result {
 #ifdef __KERNEL__
 
 struct mipid_platform_data {
-	int	nreset_gpio;
 	int	data_lines;
 
-	void	(*shutdown)(struct mipid_platform_data *pdata);
 	void	(*set_bklight_level)(struct mipid_platform_data *pdata,
 				     int level);
 	int	(*get_bklight_level)(struct mipid_platform_data *pdata);

-- 
2.34.1