| Message ID | 20200626102500.292230-1-linus.walleij@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | backlight: Delete the OT200 backlight driver | expand |
On Fri, Jun 26, 2020 at 12:25:00PM +0200, Linus Walleij wrote: > 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> I was curious about this if only because this a driver for an x86 system and I wondered how the platform device could ever have been registered. However I drew a total blank... I can find some tweaks to coreboot that make this code work better[1] but even after a careful search of the coreboot code (just in case some driver I don't know about managed to fetch the "ot200-backlight" string from the firmware) but I can't find any code within reach of a search engine (out of tree of not) that could cause this driver to activate :-( So, unless we get objections, I've reached the same view as Linus (and in this post have documented the effort involved): Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Daniel. [1] https://review.coreboot.org/cgit/coreboot.git/commit/?id=4412bc4 > --- > drivers/video/backlight/Kconfig | 7 -- > drivers/video/backlight/Makefile | 1 - > drivers/video/backlight/ot200_bl.c | 162 ----------------------------- > 3 files changed, 170 deletions(-) > delete mode 100644 drivers/video/backlight/ot200_bl.c > > diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig > index 7d22d7377606..95c546cc8774 100644 > --- 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 0c1a1524627a..2072d21b60f7 100644 > --- 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 > index 23ee7106c72a..000000000000 > --- 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"); > -- > 2.25.4 >
On Fri, 26 Jun 2020, Linus Walleij wrote: > 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> > --- > drivers/video/backlight/Kconfig | 7 -- > drivers/video/backlight/Makefile | 1 - > drivers/video/backlight/ot200_bl.c | 162 ----------------------------- > 3 files changed, 170 deletions(-) > delete mode 100644 drivers/video/backlight/ot200_bl.c Applied, thanks.
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index 7d22d7377606..95c546cc8774 100644 --- 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 0c1a1524627a..2072d21b60f7 100644 --- 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 index 23ee7106c72a..000000000000 --- 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");
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> --- drivers/video/backlight/Kconfig | 7 -- drivers/video/backlight/Makefile | 1 - drivers/video/backlight/ot200_bl.c | 162 ----------------------------- 3 files changed, 170 deletions(-) delete mode 100644 drivers/video/backlight/ot200_bl.c