backlight: Delete the OT200 backlight driver

This driver has no in-kernel users. The device can only be populated
by board files since it does not support device tree nor ACPI,
and nothing in the kernel creates a device named "ot200-backlight".

This driver has been in the kernel since 2012. If it is used by
out-of-tree code that code should have been upstreamed by now,
it's been 8 years.

It uses the idiomatic forked GPIO of the CS5535 which combines
pin control and GPIO into its private custom interface, which
causes me a headache because that is not how we do things these
days: we creates separate pin control and GPIO drivers.

Delete this unused driver.

Cc: Christian Gmeiner <christian.gmeiner@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 7d22d73..95c546c 100644 (file)
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -386,13 +386,6 @@ config BACKLIGHT_LP8788
        help
          This supports TI LP8788 backlight driver.
 
-config BACKLIGHT_OT200
-       tristate "Backlight driver for ot200 visualisation device"
-       depends on CS5535_MFGPT && GPIO_CS5535
-       help
-         To compile this driver as a module, choose M here: the module will be
-         called ot200_bl.
-
 config BACKLIGHT_PANDORA
        tristate "Backlight driver for Pandora console"
        depends on TWL4030_CORE

diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index 0c1a152..2072d21 100644 (file)
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -45,7 +45,6 @@ obj-$(CONFIG_BACKLIGHT_LP8788)                += lp8788_bl.o
 obj-$(CONFIG_BACKLIGHT_LV5207LP)       += lv5207lp.o
 obj-$(CONFIG_BACKLIGHT_MAX8925)                += max8925_bl.o
 obj-$(CONFIG_BACKLIGHT_OMAP1)          += omap1_bl.o
-obj-$(CONFIG_BACKLIGHT_OT200)          += ot200_bl.o
 obj-$(CONFIG_BACKLIGHT_PANDORA)                += pandora_bl.o
 obj-$(CONFIG_BACKLIGHT_PCF50633)       += pcf50633-backlight.o
 obj-$(CONFIG_BACKLIGHT_PWM)            += pwm_bl.o

diff --git a/drivers/video/backlight/ot200_bl.c b/drivers/video/backlight/ot200_bl.c
deleted file mode 100644 (file)
index 23ee710..0000000
--- a/drivers/video/backlight/ot200_bl.c
+++ /dev/null
@@ -1,162 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) 2012 Bachmann electronic GmbH
- *     Christian Gmeiner <christian.gmeiner@gmail.com>
- *
- * Backlight driver for ot200 visualisation device from
- * Bachmann electronic GmbH.
- */
-
-#include <linux/module.h>
-#include <linux/fb.h>
-#include <linux/backlight.h>
-#include <linux/gpio.h>
-#include <linux/platform_device.h>
-#include <linux/cs5535.h>
-
-static struct cs5535_mfgpt_timer *pwm_timer;
-
-/* this array defines the mapping of brightness in % to pwm frequency */
-static const u8 dim_table[101] = {0, 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2,
-                                 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4,
-                                 4, 5, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 9, 9,
-                                 10, 10, 11, 11, 12, 12, 13, 14, 15, 15, 16,
-                                 17, 18, 19, 20, 21, 22, 23, 24, 26, 27, 28,
-                                 30, 31, 33, 35, 37, 39, 41, 43, 45, 47, 50,
-                                 53, 55, 58, 61, 65, 68, 72, 75, 79, 84, 88,
-                                 93, 97, 103, 108, 114, 120, 126, 133, 140,
-                                 147, 155, 163};
-
-struct ot200_backlight_data {
-       int current_brightness;
-};
-
-#define GPIO_DIMM      27
-#define SCALE          1
-#define CMP1MODE       0x2     /* compare on GE; output high on compare
-                                * greater than or equal */
-#define PWM_SETUP      (SCALE | CMP1MODE << 6 | MFGPT_SETUP_CNTEN)
-#define MAX_COMP2      163
-
-static int ot200_backlight_update_status(struct backlight_device *bl)
-{
-       struct ot200_backlight_data *data = bl_get_data(bl);
-       int brightness = bl->props.brightness;
-
-       if (bl->props.state & BL_CORE_FBBLANK)
-               brightness = 0;
-
-       /* enable or disable PWM timer */
-       if (brightness == 0)
-               cs5535_mfgpt_write(pwm_timer, MFGPT_REG_SETUP, 0);
-       else if (data->current_brightness == 0) {
-               cs5535_mfgpt_write(pwm_timer, MFGPT_REG_COUNTER, 0);
-               cs5535_mfgpt_write(pwm_timer, MFGPT_REG_SETUP,
-                       MFGPT_SETUP_CNTEN);
-       }
-
-       /* apply new brightness value */
-       cs5535_mfgpt_write(pwm_timer, MFGPT_REG_CMP1,
-               MAX_COMP2 - dim_table[brightness]);
-       data->current_brightness = brightness;
-
-       return 0;
-}
-
-static int ot200_backlight_get_brightness(struct backlight_device *bl)
-{
-       struct ot200_backlight_data *data = bl_get_data(bl);
-       return data->current_brightness;
-}
-
-static const struct backlight_ops ot200_backlight_ops = {
-       .update_status  = ot200_backlight_update_status,
-       .get_brightness = ot200_backlight_get_brightness,
-};
-
-static int ot200_backlight_probe(struct platform_device *pdev)
-{
-       struct backlight_device *bl;
-       struct ot200_backlight_data *data;
-       struct backlight_properties props;
-       int retval = 0;
-
-       /* request gpio */
-       if (devm_gpio_request(&pdev->dev, GPIO_DIMM,
-                               "ot200 backlight dimmer") < 0) {
-               dev_err(&pdev->dev, "failed to request GPIO %d\n", GPIO_DIMM);
-               return -ENODEV;
-       }
-
-       /* request timer */
-       pwm_timer = cs5535_mfgpt_alloc_timer(7, MFGPT_DOMAIN_ANY);
-       if (!pwm_timer) {
-               dev_err(&pdev->dev, "MFGPT 7 not available\n");
-               return -ENODEV;
-       }
-
-       data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
-       if (!data) {
-               retval = -ENOMEM;
-               goto error_devm_kzalloc;
-       }
-
-       /* setup gpio */
-       cs5535_gpio_set(GPIO_DIMM, GPIO_OUTPUT_ENABLE);
-       cs5535_gpio_set(GPIO_DIMM, GPIO_OUTPUT_AUX1);
-
-       /* setup timer */
-       cs5535_mfgpt_write(pwm_timer, MFGPT_REG_CMP1, 0);
-       cs5535_mfgpt_write(pwm_timer, MFGPT_REG_CMP2, MAX_COMP2);
-       cs5535_mfgpt_write(pwm_timer, MFGPT_REG_SETUP, PWM_SETUP);
-
-       data->current_brightness = 100;
-       props.max_brightness = 100;
-       props.brightness = 100;
-       props.type = BACKLIGHT_RAW;
-
-       bl = devm_backlight_device_register(&pdev->dev, dev_name(&pdev->dev),
-                                       &pdev->dev, data, &ot200_backlight_ops,
-                                       &props);
-       if (IS_ERR(bl)) {
-               dev_err(&pdev->dev, "failed to register backlight\n");
-               retval = PTR_ERR(bl);
-               goto error_devm_kzalloc;
-       }
-
-       platform_set_drvdata(pdev, bl);
-
-       return 0;
-
-error_devm_kzalloc:
-       cs5535_mfgpt_free_timer(pwm_timer);
-       return retval;
-}
-
-static int ot200_backlight_remove(struct platform_device *pdev)
-{
-       /* on module unload set brightness to 100% */
-       cs5535_mfgpt_write(pwm_timer, MFGPT_REG_COUNTER, 0);
-       cs5535_mfgpt_write(pwm_timer, MFGPT_REG_SETUP, MFGPT_SETUP_CNTEN);
-       cs5535_mfgpt_write(pwm_timer, MFGPT_REG_CMP1,
-               MAX_COMP2 - dim_table[100]);
-
-       cs5535_mfgpt_free_timer(pwm_timer);
-
-       return 0;
-}
-
-static struct platform_driver ot200_backlight_driver = {
-       .driver         = {
-               .name   = "ot200-backlight",
-       },
-       .probe          = ot200_backlight_probe,
-       .remove         = ot200_backlight_remove,
-};
-
-module_platform_driver(ot200_backlight_driver);
-
-MODULE_DESCRIPTION("backlight driver for ot200 visualisation device");
-MODULE_AUTHOR("Christian Gmeiner <christian.gmeiner@gmail.com>");
-MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:ot200-backlight");