This adds support for the RGB LEDs found on the front panel of the
Turris 1.x routers. There are 8 RGB LEDs that are controlled by
CZ.NIC CPLD firmware running on Lattice FPGA.
CPLD firmware provides HW triggering mode for all LEDs except WiFi LED
which is automatically enabled after power on reset. LAN LEDs share HW
registers for RGB colors settings, so it is not possible to set different
colors for individual LAN LEDs.
CZ.NIC CPLD firmware is open source and available at:
https://gitlab.nic.cz/turris/hw/turris_cpld/-/blob/master/CZ_NIC_Router_CPLD.v
This driver uses the multicolor LED framework and HW led triggers.
Signed-off-by: Pali Rohár <[email protected]>
---
.../testing/sysfs-class-led-driver-turris1x | 23 +
drivers/leds/Kconfig | 9 +
drivers/leds/Makefile | 1 +
drivers/leds/leds-turris-1x.c | 412 ++++++++++++++++++
4 files changed, 445 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-class-led-driver-turris1x
create mode 100644 drivers/leds/leds-turris-1x.c
diff --git a/Documentation/ABI/testing/sysfs-class-led-driver-turris1x b/Documentation/ABI/testing/sysfs-class-led-driver-turris1x
new file mode 100644
index 000000000000..02be9197554d
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-led-driver-turris1x
@@ -0,0 +1,23 @@
+What: /sys/class/leds/<led>/device/brightness
+Date: July 2022
+KernelVersion: 5.20
+Contact: Pali Rohár <[email protected]>
+Description: (RW) On the back size of the Turris 1.x routers there is also
+ a button which can be used to control the intensity of all the
+ LEDs at once, so that if they are too bright, user can dim them.
+
+ The CPLD firmware cycles between 8 levels of this global
+ brightness (from 100% to 0%), but this setting can have any
+ integer value between 0 and 255. It is therefore convenient to be
+ able to change this setting from software.
+
+ Format: %u
+
+What: /sys/class/leds/<led>/device/brightness_values
+Date: July 2022
+KernelVersion: 5.20
+Contact: Pali Rohár <[email protected]>
+Description: (RW) Values of all 8 levels between which CPLD firmware cycles
+ when brightness buffer is pressed.
+
+ Format: %u %u %u %u %u %u %u %u
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index a49979f41eee..71caf45c8ac3 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -157,6 +157,15 @@ config LEDS_EL15203000
To compile this driver as a module, choose M here: the module
will be called leds-el15203000.
+config LEDS_TURRIS_1X
+ tristate "LED support for CZ.NIC's Turris 1.x"
+ depends on LEDS_CLASS_MULTICOLOR
+ depends on OF
+ select LEDS_TRIGGERS
+ help
+ This option enables support for LEDs found on the front side of
+ CZ.NIC's Turris 1.x routers.
+
config LEDS_TURRIS_OMNIA
tristate "LED support for CZ.NIC's Turris Omnia"
depends on LEDS_CLASS_MULTICOLOR
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 4fd2f92cd198..de08083dbbca 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -82,6 +82,7 @@ obj-$(CONFIG_LEDS_TCA6507) += leds-tca6507.o
obj-$(CONFIG_LEDS_TI_LMU_COMMON) += leds-ti-lmu-common.o
obj-$(CONFIG_LEDS_TLC591XX) += leds-tlc591xx.o
obj-$(CONFIG_LEDS_TPS6105X) += leds-tps6105x.o
+obj-$(CONFIG_LEDS_TURRIS_1X) += leds-turris-1x.o
obj-$(CONFIG_LEDS_TURRIS_OMNIA) += leds-turris-omnia.o
obj-$(CONFIG_LEDS_WM831X_STATUS) += leds-wm831x-status.o
obj-$(CONFIG_LEDS_WM8350) += leds-wm8350.o
diff --git a/drivers/leds/leds-turris-1x.c b/drivers/leds/leds-turris-1x.c
new file mode 100644
index 000000000000..bd566f5210c7
--- /dev/null
+++ b/drivers/leds/leds-turris-1x.c
@@ -0,0 +1,412 @@
+// SPDX-License-Identifier: GPL-2.0
+// (C) 2022 Pali Rohár <[email protected]>
+//
+// CZ.NIC's Turris 1.x LEDs driver, controlled by CPLD firmware:
+// https://gitlab.nic.cz/turris/hw/turris_cpld/-/blob/master/CZ_NIC_Router_CPLD.v
+
+#include <linux/i2c.h>
+#include <linux/led-class-multicolor.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include "leds.h"
+
+/* LED registers starts at byte 0x13 in CPLD memory map */
+#define TURRIS1X_LED_REG_OFF(reg) ((reg)-0x13)
+
+/* LEDs 1-5 share common register for setting brightness */
+#define TURRIS1X_LED_BRIGHTNESS_OFF(idx) ({ const u8 _idx = (idx) & 7; \
+ (_idx == 0) ? 0 : \
+ (_idx <= 5) ? 1 : \
+ (_idx - 4); })
+
+#define TURRIS1X_LED_BRIGHTNESS_REG(idx, color) TURRIS1X_LED_REG_OFF(0x13 + \
+ 3 * TURRIS1X_LED_BRIGHTNESS_OFF(idx) + \
+ ((color) & 3))
+#define TURRIS1X_LED_GLOBAL_LEVEL_REG TURRIS1X_LED_REG_OFF(0x20)
+#define TURRIS1X_LED_GET_GLOBAL_BRIGHTNESS_REG TURRIS1X_LED_REG_OFF(0x21)
+#define TURRIS1X_LED_SW_OVERRIDE_REG TURRIS1X_LED_REG_OFF(0x22)
+#define TURRIS1X_LED_SW_DISABLE_REG TURRIS1X_LED_REG_OFF(0x23)
+#define TURRIS1X_LED_GLOBAL_BRIGHTNESS_REG(lvl) TURRIS1X_LED_REG_OFF(0x28 + ((lvl) & 7))
+
+struct turris1x_led {
+ struct led_classdev_mc mc_cdev;
+ struct mc_subled subled_info[3];
+ u32 reg;
+ bool registered;
+};
+
+#define to_turris1x_led(l) container_of(l, struct turris1x_led, mc_cdev)
+
+struct turris1x_leds {
+ void __iomem *regs;
+ struct mutex lock;
+ struct turris1x_led leds[8];
+};
+
+static struct led_hw_trigger_type turris1x_hw_trigger_type;
+
+static int turris1x_hwtrig_activate(struct led_classdev *cdev)
+{
+ struct turris1x_leds *leds = dev_get_drvdata(cdev->dev->parent);
+ struct turris1x_led *led = to_turris1x_led(lcdev_to_mccdev(cdev));
+ u8 val;
+
+ /* Disable software control of LED */
+ mutex_lock(&leds->lock);
+ val = readb(leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG);
+ val &= ~BIT(led->reg);
+ writeb(val, leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG);
+ mutex_unlock(&leds->lock);
+
+ return 0;
+}
+
+static void turris1x_hwtrig_deactivate(struct led_classdev *cdev)
+{
+ struct turris1x_leds *leds = dev_get_drvdata(cdev->dev->parent);
+ struct turris1x_led *led = to_turris1x_led(lcdev_to_mccdev(cdev));
+ u8 val;
+
+ /* Enable software control of LED */
+ mutex_lock(&leds->lock);
+ val = readb(leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG);
+ val |= BIT(led->reg);
+ writeb(val, leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG);
+ mutex_unlock(&leds->lock);
+}
+
+static struct led_trigger turris1x_hw_trigger = {
+ .name = "turris1x-cpld",
+ .activate = turris1x_hwtrig_activate,
+ .deactivate = turris1x_hwtrig_deactivate,
+ .trigger_type = &turris1x_hw_trigger_type,
+};
+
+static enum led_brightness turris1x_led_brightness_get(struct led_classdev *cdev)
+{
+ struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
+ struct turris1x_leds *leds = dev_get_drvdata(cdev->dev->parent);
+ struct turris1x_led *led = to_turris1x_led(mc_cdev);
+
+ if (!(readb(leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG) & BIT(led->reg)))
+ return LED_ON;
+ else if (!(readb(leds->regs + TURRIS1X_LED_SW_DISABLE_REG) & BIT(led->reg)))
+ return LED_ON;
+ else
+ return LED_OFF;
+}
+
+static int turris1x_led_brightness_set_blocking(struct led_classdev *cdev,
+ enum led_brightness brightness)
+{
+ struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
+ struct turris1x_leds *leds = dev_get_drvdata(cdev->dev->parent);
+ struct turris1x_led *led = to_turris1x_led(mc_cdev);
+ int i, j;
+ u8 val;
+
+ mutex_lock(&leds->lock);
+
+ /* Set new brightness value for each color when LED is enabled */
+ if (brightness == LED_ON) {
+ led_mc_calc_color_components(mc_cdev, brightness);
+ for (i = 0; i < ARRAY_SIZE(led->subled_info); i++)
+ writeb(mc_cdev->subled_info[i].brightness,
+ leds->regs + TURRIS1X_LED_BRIGHTNESS_REG(led->reg, i));
+
+ /*
+ * LEDs 1-5 (LAN) share common color settings in same sets
+ * of HW registers and therefore it is not possible to set
+ * different colors. So when chaning color of one LED then
+ * reflect color change for all of them.
+ */
+ if (led->reg >= 1 && led->reg <= 5) {
+ for (j = 0; j < ARRAY_SIZE(leds->leds); j++) {
+ if (leds->leds[j].reg < 1 ||
+ leds->leds[j].reg > 5 ||
+ leds->leds[j].reg == led->reg)
+ continue;
+ for (i = 0; i < ARRAY_SIZE(led->subled_info); i++)
+ leds->leds[j].mc_cdev.subled_info[i].intensity =
+ mc_cdev->subled_info[i].intensity;
+ }
+ }
+ }
+
+ /* Enable / disable LED for software control */
+ val = readb(leds->regs + TURRIS1X_LED_SW_DISABLE_REG);
+ if (brightness == LED_ON && (val & BIT(led->reg)))
+ writeb(val & ~BIT(led->reg),
+ leds->regs + TURRIS1X_LED_SW_DISABLE_REG);
+ else if (brightness == LED_OFF && !(val & BIT(led->reg)))
+ writeb(val | BIT(led->reg),
+ leds->regs + TURRIS1X_LED_SW_DISABLE_REG);
+
+ mutex_unlock(&leds->lock);
+
+ return 0;
+}
+
+static int turris1x_led_register(struct device *dev, struct turris1x_leds *leds,
+ struct device_node *np, u8 val_sw_override,
+ u8 val_sw_disable)
+{
+ struct led_init_data init_data = {};
+ struct led_classdev *cdev;
+ struct turris1x_led *led;
+ int ret, color;
+ u32 reg;
+
+ ret = of_property_read_u32(np, "reg", ®);
+ if (ret || reg >= ARRAY_SIZE(leds->leds)) {
+ dev_err(dev,
+ "Node %pOF: must contain 'reg' property with values between 0 and %u\n",
+ np, (unsigned int)ARRAY_SIZE(leds->leds)-1);
+ return -EINVAL;
+ }
+
+ ret = of_property_read_u32(np, "color", &color);
+ if (ret || color != LED_COLOR_ID_RGB) {
+ dev_err(dev,
+ "Node %pOF: must contain 'color' property with value LED_COLOR_ID_RGB\n",
+ np);
+ return -EINVAL;
+ }
+
+ led = &leds->leds[reg];
+
+ if (led->registered) {
+ dev_err(dev, "Node %pOF: duplicate 'reg' property %u\n",
+ np, reg);
+ return -EINVAL;
+ }
+
+ led->registered = true;
+ led->reg = reg;
+
+ led->subled_info[0].color_index = LED_COLOR_ID_RED;
+ led->subled_info[0].intensity = 255;
+ led->subled_info[0].channel = 0;
+ led->subled_info[1].color_index = LED_COLOR_ID_GREEN;
+ led->subled_info[1].intensity = 255;
+ led->subled_info[1].channel = 1;
+ led->subled_info[2].color_index = LED_COLOR_ID_BLUE;
+ led->subled_info[2].intensity = 255;
+ led->subled_info[2].channel = 2;
+
+ led->mc_cdev.subled_info = led->subled_info;
+ led->mc_cdev.num_colors = ARRAY_SIZE(led->subled_info);
+
+ init_data.fwnode = &np->fwnode;
+
+ cdev = &led->mc_cdev.led_cdev;
+ cdev->max_brightness = LED_ON;
+ cdev->brightness_get = turris1x_led_brightness_get;
+ cdev->brightness_set_blocking = turris1x_led_brightness_set_blocking;
+
+ /* All LEDs except LED 6 (WiFi) can be controller by hardware trigger */
+ if (reg != 6)
+ cdev->trigger_type = &turris1x_hw_trigger_type;
+
+ /* Disable hardware trigger for LED 6 (WiFi) - allow software control */
+ if (reg == 6 && !(val_sw_override & BIT(6))) {
+ if (!(val_sw_disable & BIT(6))) {
+ val_sw_disable |= BIT(6);
+ writeb(val_sw_disable,
+ leds->regs + TURRIS1X_LED_SW_DISABLE_REG);
+ }
+ val_sw_override |= BIT(6);
+ writeb(val_sw_override,
+ leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG);
+ }
+
+ if (!(val_sw_override & BIT(reg)))
+ cdev->default_trigger = turris1x_hw_trigger.name;
+
+ if (!(val_sw_override & BIT(reg)) || !(val_sw_disable & BIT(reg)))
+ cdev->brightness = LED_ON;
+
+ ret = devm_led_classdev_multicolor_register_ext(dev, &led->mc_cdev,
+ &init_data);
+ if (ret) {
+ dev_err(dev, "Cannot register LED %pOF: %i\n", np, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static ssize_t brightness_show(struct device *dev, struct device_attribute *a,
+ char *buf)
+{
+ struct turris1x_leds *leds = dev_get_drvdata(dev);
+ unsigned int brightness;
+
+ /*
+ * Current brightness value is available in read-only register
+ * TURRIS1X_LED_GET_GLOBAL_BRIGHTNESS_REG. Equivalent code is:
+ * level = readb(leds->regs + TURRIS1X_LED_GLOBAL_LEVEL_REG) & 7;
+ * brightness = readb(leds->regs + TURRIS1X_LED_GLOBAL_BRIGHTNESS_REG(level));
+ */
+ brightness = readb(leds->regs + TURRIS1X_LED_GET_GLOBAL_BRIGHTNESS_REG);
+
+ return sprintf(buf, "%u\n", brightness);
+}
+
+static ssize_t brightness_store(struct device *dev, struct device_attribute *a,
+ const char *buf, size_t count)
+{
+ struct turris1x_leds *leds = dev_get_drvdata(dev);
+ int best_error, error, level, value;
+ unsigned long brightness;
+ u8 best_level;
+
+ if (kstrtoul(buf, 10, &brightness))
+ return -EINVAL;
+
+ if (brightness > 255)
+ return -EINVAL;
+
+ /*
+ * Brightness can be set only to one of 8 predefined value levels
+ * available in TURRIS1X_LED_GLOBAL_BRIGHTNESS_REG(level) registers.
+ * Choose level which has nearest value to the specified brightness.
+ */
+ best_level = 0;
+ best_error = INT_MAX;
+ for (level = 0; level < 8; level++) {
+ value = readb(leds->regs +
+ TURRIS1X_LED_GLOBAL_BRIGHTNESS_REG(level));
+ error = abs(value - (int)brightness);
+ if (best_error > error) {
+ best_error = error;
+ best_level = level;
+ }
+ }
+
+ writeb(best_level, leds->regs + TURRIS1X_LED_GLOBAL_LEVEL_REG);
+
+ return count;
+}
+static DEVICE_ATTR_RW(brightness);
+
+static ssize_t brightness_values_show(struct device *dev,
+ struct device_attribute *a, char *buf)
+{
+ struct turris1x_leds *leds = dev_get_drvdata(dev);
+ unsigned int vals[8];
+ int i;
+
+ for (i = 0; i < 8; i++)
+ vals[i] = readb(leds->regs +
+ TURRIS1X_LED_GLOBAL_BRIGHTNESS_REG(i));
+
+ return sprintf(buf, "%u %u %u %u %u %u %u %u\n", vals[0], vals[1],
+ vals[2], vals[3], vals[4], vals[5], vals[6], vals[7]);
+}
+
+static ssize_t brightness_values_store(struct device *dev,
+ struct device_attribute *a,
+ const char *buf, size_t count)
+{
+ struct turris1x_leds *leds = dev_get_drvdata(dev);
+ unsigned int vals[8];
+ int nchars;
+ int i;
+
+ if (sscanf(buf, "%u %u %u %u %u %u %u %u%n", &vals[0], &vals[1],
+ &vals[2], &vals[3], &vals[4], &vals[5], &vals[6], &vals[7],
+ &nchars) != 8 || nchars + 1 < count)
+ return -EINVAL;
+
+ for (i = 0; i < 8; i++)
+ writeb(vals[i],
+ leds->regs + TURRIS1X_LED_GLOBAL_BRIGHTNESS_REG(i));
+
+ return count;
+}
+static DEVICE_ATTR_RW(brightness_values);
+
+static struct attribute *turris1x_leds_controller_attrs[] = {
+ &dev_attr_brightness.attr,
+ &dev_attr_brightness_values.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(turris1x_leds_controller);
+
+static int turris1x_leds_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev_of_node(dev);
+ struct device_node *child;
+ struct turris1x_leds *leds;
+ struct resource *res;
+ void __iomem *regs;
+ u8 val_sw_override;
+ u8 val_sw_disable;
+ int ret;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENODEV;
+
+ regs = devm_ioremap_resource(dev, res);
+ if (IS_ERR(regs))
+ return PTR_ERR(regs);
+
+ leds = devm_kzalloc(dev, sizeof(*leds), GFP_KERNEL);
+ if (!leds)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, leds);
+
+ leds->regs = regs;
+ mutex_init(&leds->lock);
+
+ ret = devm_led_trigger_register(dev, &turris1x_hw_trigger);
+ if (ret) {
+ dev_err(dev, "Cannot register private LED trigger: %d\n", ret);
+ return ret;
+ }
+
+ val_sw_override = readb(leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG);
+ val_sw_disable = readb(leds->regs + TURRIS1X_LED_SW_DISABLE_REG);
+
+ for_each_available_child_of_node(np, child) {
+ ret = turris1x_led_register(dev, leds, child,
+ val_sw_override, val_sw_disable);
+ if (ret) {
+ of_node_put(child);
+ return ret;
+ }
+ }
+
+ ret = devm_device_add_groups(dev, turris1x_leds_controller_groups);
+ if (ret) {
+ dev_err(dev, "Could not add attribute group!\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct of_device_id of_turris1x_leds_match[] = {
+ { .compatible = "cznic,turris1x-leds" },
+ {},
+};
+
+static struct platform_driver turris1x_leds_driver = {
+ .probe = turris1x_leds_probe,
+ .driver = {
+ .name = "turris1x_leds",
+ .of_match_table = of_turris1x_leds_match,
+ },
+};
+module_platform_driver(turris1x_leds_driver);
+
+MODULE_AUTHOR("Pali Rohár <[email protected]>");
+MODULE_DESCRIPTION("CZ.NIC's Turris 1.x LEDs");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:turris1x_leds");
--
2.20.1
On Tuesday 05 July 2022 12:37:05 Marek Behún wrote:
> On Tue, 5 Jul 2022 02:04:48 +0200
> Pali Rohár <[email protected]> wrote:
>
> > This adds support for the RGB LEDs found on the front panel of the
> > Turris 1.x routers. There are 8 RGB LEDs that are controlled by
> > CZ.NIC CPLD firmware running on Lattice FPGA.
> >
> > CPLD firmware provides HW triggering mode for all LEDs except WiFi LED
> > which is automatically enabled after power on reset. LAN LEDs share HW
> > registers for RGB colors settings, so it is not possible to set different
> > colors for individual LAN LEDs.
> >
> > CZ.NIC CPLD firmware is open source and available at:
> > https://gitlab.nic.cz/turris/hw/turris_cpld/-/blob/master/CZ_NIC_Router_CPLD.v
> >
> > This driver uses the multicolor LED framework and HW led triggers.
> >
> > Signed-off-by: Pali Rohár <[email protected]>
> > ---
> > .../testing/sysfs-class-led-driver-turris1x | 23 +
> > drivers/leds/Kconfig | 9 +
> > drivers/leds/Makefile | 1 +
> > drivers/leds/leds-turris-1x.c | 412 ++++++++++++++++++
> > 4 files changed, 445 insertions(+)
> > create mode 100644 Documentation/ABI/testing/sysfs-class-led-driver-turris1x
> > create mode 100644 drivers/leds/leds-turris-1x.c
> >
> > diff --git a/Documentation/ABI/testing/sysfs-class-led-driver-turris1x b/Documentation/ABI/testing/sysfs-class-led-driver-turris1x
> > new file mode 100644
> > index 000000000000..02be9197554d
> > --- /dev/null
> > +++ b/Documentation/ABI/testing/sysfs-class-led-driver-turris1x
> > @@ -0,0 +1,23 @@
> > +What: /sys/class/leds/<led>/device/brightness
> > +Date: July 2022
> > +KernelVersion: 5.20
> > +Contact: Pali Rohár <[email protected]>
> > +Description: (RW) On the back size of the Turris 1.x routers there is also
> > + a button which can be used to control the intensity of all the
> > + LEDs at once, so that if they are too bright, user can dim them.
> > +
> > + The CPLD firmware cycles between 8 levels of this global
> > + brightness (from 100% to 0%), but this setting can have any
> > + integer value between 0 and 255. It is therefore convenient to be
> > + able to change this setting from software.
> > +
> > + Format: %u
> > +
> > +What: /sys/class/leds/<led>/device/brightness_values
> > +Date: July 2022
> > +KernelVersion: 5.20
> > +Contact: Pali Rohár <[email protected]>
> > +Description: (RW) Values of all 8 levels between which CPLD firmware cycles
> > + when brightness buffer is pressed.
>
> *button
OK.
> > + Format: %u %u %u %u %u %u %u %u
> > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> > index a49979f41eee..71caf45c8ac3 100644
> > --- a/drivers/leds/Kconfig
> > +++ b/drivers/leds/Kconfig
> > @@ -157,6 +157,15 @@ config LEDS_EL15203000
> > To compile this driver as a module, choose M here: the module
> > will be called leds-el15203000.
> >
> > +config LEDS_TURRIS_1X
> > + tristate "LED support for CZ.NIC's Turris 1.x"
> > + depends on LEDS_CLASS_MULTICOLOR
> > + depends on OF
> > + select LEDS_TRIGGERS
> > + help
> > + This option enables support for LEDs found on the front side of
> > + CZ.NIC's Turris 1.x routers.
> > +
> > config LEDS_TURRIS_OMNIA
> > tristate "LED support for CZ.NIC's Turris Omnia"
> > depends on LEDS_CLASS_MULTICOLOR
> > diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> > index 4fd2f92cd198..de08083dbbca 100644
> > --- a/drivers/leds/Makefile
> > +++ b/drivers/leds/Makefile
> > @@ -82,6 +82,7 @@ obj-$(CONFIG_LEDS_TCA6507) += leds-tca6507.o
> > obj-$(CONFIG_LEDS_TI_LMU_COMMON) += leds-ti-lmu-common.o
> > obj-$(CONFIG_LEDS_TLC591XX) += leds-tlc591xx.o
> > obj-$(CONFIG_LEDS_TPS6105X) += leds-tps6105x.o
> > +obj-$(CONFIG_LEDS_TURRIS_1X) += leds-turris-1x.o
> > obj-$(CONFIG_LEDS_TURRIS_OMNIA) += leds-turris-omnia.o
> > obj-$(CONFIG_LEDS_WM831X_STATUS) += leds-wm831x-status.o
> > obj-$(CONFIG_LEDS_WM8350) += leds-wm8350.o
> > diff --git a/drivers/leds/leds-turris-1x.c b/drivers/leds/leds-turris-1x.c
> > new file mode 100644
> > index 000000000000..bd566f5210c7
> > --- /dev/null
> > +++ b/drivers/leds/leds-turris-1x.c
> > @@ -0,0 +1,412 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +// (C) 2022 Pali Rohár <[email protected]>
> > +//
> > +// CZ.NIC's Turris 1.x LEDs driver, controlled by CPLD firmware:
> > +// https://gitlab.nic.cz/turris/hw/turris_cpld/-/blob/master/CZ_NIC_Router_CPLD.v
> > +
> > +#include <linux/i2c.h>
> > +#include <linux/led-class-multicolor.h>
> > +#include <linux/module.h>
> > +#include <linux/mutex.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include "leds.h"
> > +
> > +/* LED registers starts at byte 0x13 in CPLD memory map */
> > +#define TURRIS1X_LED_REG_OFF(reg) ((reg)-0x13)
> > +
> > +/* LEDs 1-5 share common register for setting brightness */
> > +#define TURRIS1X_LED_BRIGHTNESS_OFF(idx) ({ const u8 _idx = (idx) & 7; \
> > + (_idx == 0) ? 0 : \
> > + (_idx <= 5) ? 1 : \
> > + (_idx - 4); })
> > +
> > +#define TURRIS1X_LED_BRIGHTNESS_REG(idx, color) TURRIS1X_LED_REG_OFF(0x13 + \
> > + 3 * TURRIS1X_LED_BRIGHTNESS_OFF(idx) + \
> > + ((color) & 3))
> > +#define TURRIS1X_LED_GLOBAL_LEVEL_REG TURRIS1X_LED_REG_OFF(0x20)
> > +#define TURRIS1X_LED_GET_GLOBAL_BRIGHTNESS_REG TURRIS1X_LED_REG_OFF(0x21)
> > +#define TURRIS1X_LED_SW_OVERRIDE_REG TURRIS1X_LED_REG_OFF(0x22)
> > +#define TURRIS1X_LED_SW_DISABLE_REG TURRIS1X_LED_REG_OFF(0x23)
> > +#define TURRIS1X_LED_GLOBAL_BRIGHTNESS_REG(lvl) TURRIS1X_LED_REG_OFF(0x28 + ((lvl) & 7))
> > +
> > +struct turris1x_led {
> > + struct led_classdev_mc mc_cdev;
> > + struct mc_subled subled_info[3];
> > + u32 reg;
> > + bool registered;
> > +};
> > +
> > +#define to_turris1x_led(l) container_of(l, struct turris1x_led, mc_cdev)
> > +
> > +struct turris1x_leds {
> > + void __iomem *regs;
> > + struct mutex lock;
> > + struct turris1x_led leds[8];
> > +};
> > +
> > +static struct led_hw_trigger_type turris1x_hw_trigger_type;
> > +
> > +static int turris1x_hwtrig_activate(struct led_classdev *cdev)
> > +{
> > + struct turris1x_leds *leds = dev_get_drvdata(cdev->dev->parent);
> > + struct turris1x_led *led = to_turris1x_led(lcdev_to_mccdev(cdev));
> > + u8 val;
> > +
> > + /* Disable software control of LED */
> > + mutex_lock(&leds->lock);
> > + val = readb(leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG);
> > + val &= ~BIT(led->reg);
> > + writeb(val, leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG);
> > + mutex_unlock(&leds->lock);
> > +
> > + return 0;
> > +}
> > +
> > +static void turris1x_hwtrig_deactivate(struct led_classdev *cdev)
> > +{
> > + struct turris1x_leds *leds = dev_get_drvdata(cdev->dev->parent);
> > + struct turris1x_led *led = to_turris1x_led(lcdev_to_mccdev(cdev));
> > + u8 val;
> > +
> > + /* Enable software control of LED */
> > + mutex_lock(&leds->lock);
> > + val = readb(leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG);
> > + val |= BIT(led->reg);
> > + writeb(val, leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG);
> > + mutex_unlock(&leds->lock);
> > +}
> > +
> > +static struct led_trigger turris1x_hw_trigger = {
> > + .name = "turris1x-cpld",
> > + .activate = turris1x_hwtrig_activate,
> > + .deactivate = turris1x_hwtrig_deactivate,
> > + .trigger_type = &turris1x_hw_trigger_type,
> > +};
> > +
> > +static enum led_brightness turris1x_led_brightness_get(struct led_classdev *cdev)
> > +{
> > + struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
> > + struct turris1x_leds *leds = dev_get_drvdata(cdev->dev->parent);
> > + struct turris1x_led *led = to_turris1x_led(mc_cdev);
> > +
> > + if (!(readb(leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG) & BIT(led->reg)))
> > + return LED_ON;
> > + else if (!(readb(leds->regs + TURRIS1X_LED_SW_DISABLE_REG) & BIT(led->reg)))
> > + return LED_ON;
> > + else
> > + return LED_OFF;
> > +}
>
> LED_ON and LED_OFF are deprecated, as says in include/linux/leds.h.
> Just return 0 or 1.
Ok!
> > +
> > +static int turris1x_led_brightness_set_blocking(struct led_classdev *cdev,
> > + enum led_brightness brightness)
> > +{
>
> The register write should be immediate, we don't need to use the
> _blocking variant here. On Omnia we need to, cause I2C is slow.
Ok! (I thought that usage of mutex is also blocking variant)
> > + struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
> > + struct turris1x_leds *leds = dev_get_drvdata(cdev->dev->parent);
> > + struct turris1x_led *led = to_turris1x_led(mc_cdev);
> > + int i, j;
> > + u8 val;
> > +
> > + mutex_lock(&leds->lock);
> > +
> > + /* Set new brightness value for each color when LED is enabled */
> > + if (brightness == LED_ON) {
>
> if (brightness)
>
> So this will also make sure that I can change LED color by writing
> new color to multi_intensity and 1 to brightness, even if the LED is in
> HW control mode, am I correct?
This is for ability to disable LAN1 and enable LAN2, both in SW mode
which shares TURRIS1X_LED_BRIGHTNESS_REG register. Disabling LED cause
that mc_cdev->subled_info[0..3].brightness is 0.
> > + led_mc_calc_color_components(mc_cdev, brightness);
> > + for (i = 0; i < ARRAY_SIZE(led->subled_info); i++)
> > + writeb(mc_cdev->subled_info[i].brightness,
> > + leds->regs + TURRIS1X_LED_BRIGHTNESS_REG(led->reg, i));
> > +
> > + /*
> > + * LEDs 1-5 (LAN) share common color settings in same sets
> > + * of HW registers and therefore it is not possible to set
> > + * different colors. So when chaning color of one LED then
> > + * reflect color change for all of them.
> > + */
> > + if (led->reg >= 1 && led->reg <= 5) {
> > + for (j = 0; j < ARRAY_SIZE(leds->leds); j++) {
> > + if (leds->leds[j].reg < 1 ||
> > + leds->leds[j].reg > 5 ||
> > + leds->leds[j].reg == led->reg)
> > + continue;
> > + for (i = 0; i < ARRAY_SIZE(led->subled_info); i++)
> > + leds->leds[j].mc_cdev.subled_info[i].intensity =
> > + mc_cdev->subled_info[i].intensity;
> > + }
>
> I don't consider this a problem
I think it is a problem, to ensure that 'cat multi_intensity' for every
LAN led reports correct (= current) value. If you change multi_intensity
of LAN1 then color is changed for all LAN* but sysfs reports new value
only for LAN1 and old values for LAN2..5.
> but suppose that we are rewriting the
> other LEDs colors, and at the same time someone is reading from sysfs
> the multi_intensity file of a LED that is being rewritten. This can
> result in wrong value being read, right? But probably only on multi-core
> systems...
This is eventual inconsistency and I do not consider this as issue.
Moreover achieving eventual consistency here is probably not possible as
there is still some latency between "writeb" call and real reflection of
LED color on the hardware.
> > + }
> > + }
> > +
> > + /* Enable / disable LED for software control */
> > + val = readb(leds->regs + TURRIS1X_LED_SW_DISABLE_REG);
> > + if (brightness == LED_ON && (val & BIT(led->reg)))
> > + writeb(val & ~BIT(led->reg),
> > + leds->regs + TURRIS1X_LED_SW_DISABLE_REG);
> > + else if (brightness == LED_OFF && !(val & BIT(led->reg)))
> > + writeb(val | BIT(led->reg),
> > + leds->regs + TURRIS1X_LED_SW_DISABLE_REG);
>
> Pls just use brightness or !brightness.
Ok!
> Or maybe just write the value?
> Is the register write expensive on the CPLD or why are you trying to
> avoid it if unnecessary?
I just do not see any reason to do unnecessary writes.
> > + mutex_unlock(&leds->lock);
> > +
> > + return 0;
> > +}
> > +
> > +static int turris1x_led_register(struct device *dev, struct turris1x_leds *leds,
> > + struct device_node *np, u8 val_sw_override,
> > + u8 val_sw_disable)
> > +{
> > + struct led_init_data init_data = {};
> > + struct led_classdev *cdev;
> > + struct turris1x_led *led;
> > + int ret, color;
> > + u32 reg;
> > +
> > + ret = of_property_read_u32(np, "reg", ®);
> > + if (ret || reg >= ARRAY_SIZE(leds->leds)) {
> > + dev_err(dev,
> > + "Node %pOF: must contain 'reg' property with values between 0 and %u\n",
> > + np, (unsigned int)ARRAY_SIZE(leds->leds)-1);
>
> Weird that checkpatch doesn't warn about spaces around the minus
> operator in ARRAY_SIZE()-1.
>
>
> > + return -EINVAL;
> > + }
> > +
> > + ret = of_property_read_u32(np, "color", &color);
> > + if (ret || color != LED_COLOR_ID_RGB) {
> > + dev_err(dev,
> > + "Node %pOF: must contain 'color' property with value LED_COLOR_ID_RGB\n",
> > + np);
> > + return -EINVAL;
> > + }
> > +
> > + led = &leds->leds[reg];
> > +
> > + if (led->registered) {
> > + dev_err(dev, "Node %pOF: duplicate 'reg' property %u\n",
> > + np, reg);
> > + return -EINVAL;
> > + }
> > +
> > + led->registered = true;
> > + led->reg = reg;
> > +
> > + led->subled_info[0].color_index = LED_COLOR_ID_RED;
> > + led->subled_info[0].intensity = 255;
> > + led->subled_info[0].channel = 0;
> > + led->subled_info[1].color_index = LED_COLOR_ID_GREEN;
> > + led->subled_info[1].intensity = 255;
> > + led->subled_info[1].channel = 1;
> > + led->subled_info[2].color_index = LED_COLOR_ID_BLUE;
> > + led->subled_info[2].intensity = 255;
> > + led->subled_info[2].channel = 2;
> > +
> > + led->mc_cdev.subled_info = led->subled_info;
> > + led->mc_cdev.num_colors = ARRAY_SIZE(led->subled_info);
> > +
> > + init_data.fwnode = &np->fwnode;
> > +
> > + cdev = &led->mc_cdev.led_cdev;
> > + cdev->max_brightness = LED_ON;
>
> s/LED_ON/1/
>
> > + cdev->brightness_get = turris1x_led_brightness_get;
> > + cdev->brightness_set_blocking = turris1x_led_brightness_set_blocking;
>
> See above about _blocking.
>
> > +
> > + /* All LEDs except LED 6 (WiFi) can be controller by hardware trigger */
> > + if (reg != 6)
> > + cdev->trigger_type = &turris1x_hw_trigger_type;
> > +
> > + /* Disable hardware trigger for LED 6 (WiFi) - allow software control */
> > + if (reg == 6 && !(val_sw_override & BIT(6))) {
> > + if (!(val_sw_disable & BIT(6))) {
> > + val_sw_disable |= BIT(6);
> > + writeb(val_sw_disable,
> > + leds->regs + TURRIS1X_LED_SW_DISABLE_REG);
> > + }
> > + val_sw_override |= BIT(6);
> > + writeb(val_sw_override,
> > + leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG);
>
> Again, is the register write that expensive that you try to avoid it if
> the corresponding bit has the value you want?
>
> > + }
> > +
> > + if (!(val_sw_override & BIT(reg)))
> > + cdev->default_trigger = turris1x_hw_trigger.name;
> > +
> > + if (!(val_sw_override & BIT(reg)) || !(val_sw_disable & BIT(reg)))
> > + cdev->brightness = LED_ON;
>
> s/LED_ON/1/
>
> > + ret = devm_led_classdev_multicolor_register_ext(dev, &led->mc_cdev,
> > + &init_data);
> > + if (ret) {
> > + dev_err(dev, "Cannot register LED %pOF: %i\n", np, ret);
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static ssize_t brightness_show(struct device *dev, struct device_attribute *a,
> > + char *buf)
> > +{
> > + struct turris1x_leds *leds = dev_get_drvdata(dev);
> > + unsigned int brightness;
> > +
> > + /*
> > + * Current brightness value is available in read-only register
> > + * TURRIS1X_LED_GET_GLOBAL_BRIGHTNESS_REG. Equivalent code is:
> > + * level = readb(leds->regs + TURRIS1X_LED_GLOBAL_LEVEL_REG) & 7;
> > + * brightness = readb(leds->regs + TURRIS1X_LED_GLOBAL_BRIGHTNESS_REG(level));
> > + */
> > + brightness = readb(leds->regs + TURRIS1X_LED_GET_GLOBAL_BRIGHTNESS_REG);
> > +
> > + return sprintf(buf, "%u\n", brightness);
> > +}
> > +
> > +static ssize_t brightness_store(struct device *dev, struct device_attribute *a,
> > + const char *buf, size_t count)
> > +{
> > + struct turris1x_leds *leds = dev_get_drvdata(dev);
> > + int best_error, error, level, value;
> > + unsigned long brightness;
> > + u8 best_level;
> > +
> > + if (kstrtoul(buf, 10, &brightness))
> > + return -EINVAL;
> > +
> > + if (brightness > 255)
> > + return -EINVAL;
> > +
> > + /*
> > + * Brightness can be set only to one of 8 predefined value levels
> > + * available in TURRIS1X_LED_GLOBAL_BRIGHTNESS_REG(level) registers.
> > + * Choose level which has nearest value to the specified brightness.
> > + */
>
> Hmm. Wouldn't it make more sense to simply have the global brightness
> accept values from 0 to 7, instead of mapping it to 256 values? And
> call it something like selected_brightness_index?
All other drivers have brightness entry which operates on monotone
brightness property.
Brightness levels do not have to be monotone and by default are
decreasing: 0 = brightness with higher intensity; 7 = no intensity (off)
I cannot image who would like or prefer usage of such API.
Just stick with existing APIs. "brightness" entry takes intensity value
which is monotone, 0 the lowest, MAX (=255) the highest.
For setting individual level values I introduced a new entry
"brightness_values".
> > + best_level = 0;
> > + best_error = INT_MAX;
> > + for (level = 0; level < 8; level++) {
> > + value = readb(leds->regs +
> > + TURRIS1X_LED_GLOBAL_BRIGHTNESS_REG(level));
> > + error = abs(value - (int)brightness);
> > + if (best_error > error) {
> > + best_error = error;
> > + best_level = level;
> > + }
> > + }
> > +
> > + writeb(best_level, leds->regs + TURRIS1X_LED_GLOBAL_LEVEL_REG);
> > +
> > + return count;
> > +}
> > +static DEVICE_ATTR_RW(brightness);
> > +
> > +static ssize_t brightness_values_show(struct device *dev,
> > + struct device_attribute *a, char *buf)
> > +{
> > + struct turris1x_leds *leds = dev_get_drvdata(dev);
> > + unsigned int vals[8];
> > + int i;
> > +
> > + for (i = 0; i < 8; i++)
> > + vals[i] = readb(leds->regs +
> > + TURRIS1X_LED_GLOBAL_BRIGHTNESS_REG(i));
> > +
> > + return sprintf(buf, "%u %u %u %u %u %u %u %u\n", vals[0], vals[1],
> > + vals[2], vals[3], vals[4], vals[5], vals[6], vals[7]);
> > +}
> > +
> > +static ssize_t brightness_values_store(struct device *dev,
> > + struct device_attribute *a,
> > + const char *buf, size_t count)
> > +{
> > + struct turris1x_leds *leds = dev_get_drvdata(dev);
> > + unsigned int vals[8];
> > + int nchars;
> > + int i;
> > +
> > + if (sscanf(buf, "%u %u %u %u %u %u %u %u%n", &vals[0], &vals[1],
> > + &vals[2], &vals[3], &vals[4], &vals[5], &vals[6], &vals[7],
> > + &nchars) != 8 || nchars + 1 < count)
> > + return -EINVAL;
> > +
> > + for (i = 0; i < 8; i++)
> > + writeb(vals[i],
> > + leds->regs + TURRIS1X_LED_GLOBAL_BRIGHTNESS_REG(i));
> > +
> > + return count;
> > +}
> > +static DEVICE_ATTR_RW(brightness_values);
> > +
> > +static struct attribute *turris1x_leds_controller_attrs[] = {
> > + &dev_attr_brightness.attr,
> > + &dev_attr_brightness_values.attr,
> > + NULL,
> > +};
> > +ATTRIBUTE_GROUPS(turris1x_leds_controller);
> > +
> > +static int turris1x_leds_probe(struct platform_device *pdev)
> > +{
> > + struct device *dev = &pdev->dev;
> > + struct device_node *np = dev_of_node(dev);
> > + struct device_node *child;
> > + struct turris1x_leds *leds;
> > + struct resource *res;
> > + void __iomem *regs;
> > + u8 val_sw_override;
> > + u8 val_sw_disable;
> > + int ret;
> > +
> > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > + if (!res)
> > + return -ENODEV;
> > +
> > + regs = devm_ioremap_resource(dev, res);
> > + if (IS_ERR(regs))
> > + return PTR_ERR(regs);
> > +
> > + leds = devm_kzalloc(dev, sizeof(*leds), GFP_KERNEL);
> > + if (!leds)
> > + return -ENOMEM;
> > +
> > + platform_set_drvdata(pdev, leds);
> > +
> > + leds->regs = regs;
> > + mutex_init(&leds->lock);
> > +
> > + ret = devm_led_trigger_register(dev, &turris1x_hw_trigger);
> > + if (ret) {
> > + dev_err(dev, "Cannot register private LED trigger: %d\n", ret);
> > + return ret;
> > + }
> > +
> > + val_sw_override = readb(leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG);
> > + val_sw_disable = readb(leds->regs + TURRIS1X_LED_SW_DISABLE_REG);
> > +
> > + for_each_available_child_of_node(np, child) {
> > + ret = turris1x_led_register(dev, leds, child,
> > + val_sw_override, val_sw_disable);
> > + if (ret) {
> > + of_node_put(child);
> > + return ret;
> > + }
> > + }
> > +
> > + ret = devm_device_add_groups(dev, turris1x_leds_controller_groups);
> > + if (ret) {
> > + dev_err(dev, "Could not add attribute group!\n");
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static const struct of_device_id of_turris1x_leds_match[] = {
> > + { .compatible = "cznic,turris1x-leds" },
> > + {},
> > +};
> > +
> > +static struct platform_driver turris1x_leds_driver = {
> > + .probe = turris1x_leds_probe,
> > + .driver = {
> > + .name = "turris1x_leds",
> > + .of_match_table = of_turris1x_leds_match,
> > + },
> > +};
> > +module_platform_driver(turris1x_leds_driver);
> > +
> > +MODULE_AUTHOR("Pali Rohár <[email protected]>");
> > +MODULE_DESCRIPTION("CZ.NIC's Turris 1.x LEDs");
> > +MODULE_LICENSE("GPL");
> > +MODULE_ALIAS("platform:turris1x_leds");
>
On Tue, 5 Jul 2022 02:04:48 +0200
Pali Rohár <[email protected]> wrote:
> This adds support for the RGB LEDs found on the front panel of the
> Turris 1.x routers. There are 8 RGB LEDs that are controlled by
> CZ.NIC CPLD firmware running on Lattice FPGA.
>
> CPLD firmware provides HW triggering mode for all LEDs except WiFi LED
> which is automatically enabled after power on reset. LAN LEDs share HW
> registers for RGB colors settings, so it is not possible to set different
> colors for individual LAN LEDs.
>
> CZ.NIC CPLD firmware is open source and available at:
> https://gitlab.nic.cz/turris/hw/turris_cpld/-/blob/master/CZ_NIC_Router_CPLD.v
>
> This driver uses the multicolor LED framework and HW led triggers.
>
> Signed-off-by: Pali Rohár <[email protected]>
> ---
> .../testing/sysfs-class-led-driver-turris1x | 23 +
> drivers/leds/Kconfig | 9 +
> drivers/leds/Makefile | 1 +
> drivers/leds/leds-turris-1x.c | 412 ++++++++++++++++++
> 4 files changed, 445 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-class-led-driver-turris1x
> create mode 100644 drivers/leds/leds-turris-1x.c
>
> diff --git a/Documentation/ABI/testing/sysfs-class-led-driver-turris1x b/Documentation/ABI/testing/sysfs-class-led-driver-turris1x
> new file mode 100644
> index 000000000000..02be9197554d
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-class-led-driver-turris1x
> @@ -0,0 +1,23 @@
> +What: /sys/class/leds/<led>/device/brightness
> +Date: July 2022
> +KernelVersion: 5.20
> +Contact: Pali Rohár <[email protected]>
> +Description: (RW) On the back size of the Turris 1.x routers there is also
> + a button which can be used to control the intensity of all the
> + LEDs at once, so that if they are too bright, user can dim them.
> +
> + The CPLD firmware cycles between 8 levels of this global
> + brightness (from 100% to 0%), but this setting can have any
> + integer value between 0 and 255. It is therefore convenient to be
> + able to change this setting from software.
> +
> + Format: %u
> +
> +What: /sys/class/leds/<led>/device/brightness_values
> +Date: July 2022
> +KernelVersion: 5.20
> +Contact: Pali Rohár <[email protected]>
> +Description: (RW) Values of all 8 levels between which CPLD firmware cycles
> + when brightness buffer is pressed.
*button
> + Format: %u %u %u %u %u %u %u %u
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index a49979f41eee..71caf45c8ac3 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -157,6 +157,15 @@ config LEDS_EL15203000
> To compile this driver as a module, choose M here: the module
> will be called leds-el15203000.
>
> +config LEDS_TURRIS_1X
> + tristate "LED support for CZ.NIC's Turris 1.x"
> + depends on LEDS_CLASS_MULTICOLOR
> + depends on OF
> + select LEDS_TRIGGERS
> + help
> + This option enables support for LEDs found on the front side of
> + CZ.NIC's Turris 1.x routers.
> +
> config LEDS_TURRIS_OMNIA
> tristate "LED support for CZ.NIC's Turris Omnia"
> depends on LEDS_CLASS_MULTICOLOR
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index 4fd2f92cd198..de08083dbbca 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -82,6 +82,7 @@ obj-$(CONFIG_LEDS_TCA6507) += leds-tca6507.o
> obj-$(CONFIG_LEDS_TI_LMU_COMMON) += leds-ti-lmu-common.o
> obj-$(CONFIG_LEDS_TLC591XX) += leds-tlc591xx.o
> obj-$(CONFIG_LEDS_TPS6105X) += leds-tps6105x.o
> +obj-$(CONFIG_LEDS_TURRIS_1X) += leds-turris-1x.o
> obj-$(CONFIG_LEDS_TURRIS_OMNIA) += leds-turris-omnia.o
> obj-$(CONFIG_LEDS_WM831X_STATUS) += leds-wm831x-status.o
> obj-$(CONFIG_LEDS_WM8350) += leds-wm8350.o
> diff --git a/drivers/leds/leds-turris-1x.c b/drivers/leds/leds-turris-1x.c
> new file mode 100644
> index 000000000000..bd566f5210c7
> --- /dev/null
> +++ b/drivers/leds/leds-turris-1x.c
> @@ -0,0 +1,412 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// (C) 2022 Pali Rohár <[email protected]>
> +//
> +// CZ.NIC's Turris 1.x LEDs driver, controlled by CPLD firmware:
> +// https://gitlab.nic.cz/turris/hw/turris_cpld/-/blob/master/CZ_NIC_Router_CPLD.v
> +
> +#include <linux/i2c.h>
> +#include <linux/led-class-multicolor.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include "leds.h"
> +
> +/* LED registers starts at byte 0x13 in CPLD memory map */
> +#define TURRIS1X_LED_REG_OFF(reg) ((reg)-0x13)
> +
> +/* LEDs 1-5 share common register for setting brightness */
> +#define TURRIS1X_LED_BRIGHTNESS_OFF(idx) ({ const u8 _idx = (idx) & 7; \
> + (_idx == 0) ? 0 : \
> + (_idx <= 5) ? 1 : \
> + (_idx - 4); })
> +
> +#define TURRIS1X_LED_BRIGHTNESS_REG(idx, color) TURRIS1X_LED_REG_OFF(0x13 + \
> + 3 * TURRIS1X_LED_BRIGHTNESS_OFF(idx) + \
> + ((color) & 3))
> +#define TURRIS1X_LED_GLOBAL_LEVEL_REG TURRIS1X_LED_REG_OFF(0x20)
> +#define TURRIS1X_LED_GET_GLOBAL_BRIGHTNESS_REG TURRIS1X_LED_REG_OFF(0x21)
> +#define TURRIS1X_LED_SW_OVERRIDE_REG TURRIS1X_LED_REG_OFF(0x22)
> +#define TURRIS1X_LED_SW_DISABLE_REG TURRIS1X_LED_REG_OFF(0x23)
> +#define TURRIS1X_LED_GLOBAL_BRIGHTNESS_REG(lvl) TURRIS1X_LED_REG_OFF(0x28 + ((lvl) & 7))
> +
> +struct turris1x_led {
> + struct led_classdev_mc mc_cdev;
> + struct mc_subled subled_info[3];
> + u32 reg;
> + bool registered;
> +};
> +
> +#define to_turris1x_led(l) container_of(l, struct turris1x_led, mc_cdev)
> +
> +struct turris1x_leds {
> + void __iomem *regs;
> + struct mutex lock;
> + struct turris1x_led leds[8];
> +};
> +
> +static struct led_hw_trigger_type turris1x_hw_trigger_type;
> +
> +static int turris1x_hwtrig_activate(struct led_classdev *cdev)
> +{
> + struct turris1x_leds *leds = dev_get_drvdata(cdev->dev->parent);
> + struct turris1x_led *led = to_turris1x_led(lcdev_to_mccdev(cdev));
> + u8 val;
> +
> + /* Disable software control of LED */
> + mutex_lock(&leds->lock);
> + val = readb(leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG);
> + val &= ~BIT(led->reg);
> + writeb(val, leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG);
> + mutex_unlock(&leds->lock);
> +
> + return 0;
> +}
> +
> +static void turris1x_hwtrig_deactivate(struct led_classdev *cdev)
> +{
> + struct turris1x_leds *leds = dev_get_drvdata(cdev->dev->parent);
> + struct turris1x_led *led = to_turris1x_led(lcdev_to_mccdev(cdev));
> + u8 val;
> +
> + /* Enable software control of LED */
> + mutex_lock(&leds->lock);
> + val = readb(leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG);
> + val |= BIT(led->reg);
> + writeb(val, leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG);
> + mutex_unlock(&leds->lock);
> +}
> +
> +static struct led_trigger turris1x_hw_trigger = {
> + .name = "turris1x-cpld",
> + .activate = turris1x_hwtrig_activate,
> + .deactivate = turris1x_hwtrig_deactivate,
> + .trigger_type = &turris1x_hw_trigger_type,
> +};
> +
> +static enum led_brightness turris1x_led_brightness_get(struct led_classdev *cdev)
> +{
> + struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
> + struct turris1x_leds *leds = dev_get_drvdata(cdev->dev->parent);
> + struct turris1x_led *led = to_turris1x_led(mc_cdev);
> +
> + if (!(readb(leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG) & BIT(led->reg)))
> + return LED_ON;
> + else if (!(readb(leds->regs + TURRIS1X_LED_SW_DISABLE_REG) & BIT(led->reg)))
> + return LED_ON;
> + else
> + return LED_OFF;
> +}
LED_ON and LED_OFF are deprecated, as says in include/linux/leds.h.
Just return 0 or 1.
> +
> +static int turris1x_led_brightness_set_blocking(struct led_classdev *cdev,
> + enum led_brightness brightness)
> +{
The register write should be immediate, we don't need to use the
_blocking variant here. On Omnia we need to, cause I2C is slow.
> + struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
> + struct turris1x_leds *leds = dev_get_drvdata(cdev->dev->parent);
> + struct turris1x_led *led = to_turris1x_led(mc_cdev);
> + int i, j;
> + u8 val;
> +
> + mutex_lock(&leds->lock);
> +
> + /* Set new brightness value for each color when LED is enabled */
> + if (brightness == LED_ON) {
if (brightness)
So this will also make sure that I can change LED color by writing
new color to multi_intensity and 1 to brightness, even if the LED is in
HW control mode, am I correct?
> + led_mc_calc_color_components(mc_cdev, brightness);
> + for (i = 0; i < ARRAY_SIZE(led->subled_info); i++)
> + writeb(mc_cdev->subled_info[i].brightness,
> + leds->regs + TURRIS1X_LED_BRIGHTNESS_REG(led->reg, i));
> +
> + /*
> + * LEDs 1-5 (LAN) share common color settings in same sets
> + * of HW registers and therefore it is not possible to set
> + * different colors. So when chaning color of one LED then
> + * reflect color change for all of them.
> + */
> + if (led->reg >= 1 && led->reg <= 5) {
> + for (j = 0; j < ARRAY_SIZE(leds->leds); j++) {
> + if (leds->leds[j].reg < 1 ||
> + leds->leds[j].reg > 5 ||
> + leds->leds[j].reg == led->reg)
> + continue;
> + for (i = 0; i < ARRAY_SIZE(led->subled_info); i++)
> + leds->leds[j].mc_cdev.subled_info[i].intensity =
> + mc_cdev->subled_info[i].intensity;
> + }
I don't consider this a problem, but suppose that we are rewriting the
other LEDs colors, and at the same time someone is reading from sysfs
the multi_intensity file of a LED that is being rewritten. This can
result in wrong value being read, right? But probably only on multi-core
systems...
> + }
> + }
> +
> + /* Enable / disable LED for software control */
> + val = readb(leds->regs + TURRIS1X_LED_SW_DISABLE_REG);
> + if (brightness == LED_ON && (val & BIT(led->reg)))
> + writeb(val & ~BIT(led->reg),
> + leds->regs + TURRIS1X_LED_SW_DISABLE_REG);
> + else if (brightness == LED_OFF && !(val & BIT(led->reg)))
> + writeb(val | BIT(led->reg),
> + leds->regs + TURRIS1X_LED_SW_DISABLE_REG);
Pls just use brightness or !brightness. Or maybe just write the value?
Is the register write expensive on the CPLD or why are you trying to
avoid it if unnecessary?
> + mutex_unlock(&leds->lock);
> +
> + return 0;
> +}
> +
> +static int turris1x_led_register(struct device *dev, struct turris1x_leds *leds,
> + struct device_node *np, u8 val_sw_override,
> + u8 val_sw_disable)
> +{
> + struct led_init_data init_data = {};
> + struct led_classdev *cdev;
> + struct turris1x_led *led;
> + int ret, color;
> + u32 reg;
> +
> + ret = of_property_read_u32(np, "reg", ®);
> + if (ret || reg >= ARRAY_SIZE(leds->leds)) {
> + dev_err(dev,
> + "Node %pOF: must contain 'reg' property with values between 0 and %u\n",
> + np, (unsigned int)ARRAY_SIZE(leds->leds)-1);
Weird that checkpatch doesn't warn about spaces around the minus
operator in ARRAY_SIZE()-1.
> + return -EINVAL;
> + }
> +
> + ret = of_property_read_u32(np, "color", &color);
> + if (ret || color != LED_COLOR_ID_RGB) {
> + dev_err(dev,
> + "Node %pOF: must contain 'color' property with value LED_COLOR_ID_RGB\n",
> + np);
> + return -EINVAL;
> + }
> +
> + led = &leds->leds[reg];
> +
> + if (led->registered) {
> + dev_err(dev, "Node %pOF: duplicate 'reg' property %u\n",
> + np, reg);
> + return -EINVAL;
> + }
> +
> + led->registered = true;
> + led->reg = reg;
> +
> + led->subled_info[0].color_index = LED_COLOR_ID_RED;
> + led->subled_info[0].intensity = 255;
> + led->subled_info[0].channel = 0;
> + led->subled_info[1].color_index = LED_COLOR_ID_GREEN;
> + led->subled_info[1].intensity = 255;
> + led->subled_info[1].channel = 1;
> + led->subled_info[2].color_index = LED_COLOR_ID_BLUE;
> + led->subled_info[2].intensity = 255;
> + led->subled_info[2].channel = 2;
> +
> + led->mc_cdev.subled_info = led->subled_info;
> + led->mc_cdev.num_colors = ARRAY_SIZE(led->subled_info);
> +
> + init_data.fwnode = &np->fwnode;
> +
> + cdev = &led->mc_cdev.led_cdev;
> + cdev->max_brightness = LED_ON;
s/LED_ON/1/
> + cdev->brightness_get = turris1x_led_brightness_get;
> + cdev->brightness_set_blocking = turris1x_led_brightness_set_blocking;
See above about _blocking.
> +
> + /* All LEDs except LED 6 (WiFi) can be controller by hardware trigger */
> + if (reg != 6)
> + cdev->trigger_type = &turris1x_hw_trigger_type;
> +
> + /* Disable hardware trigger for LED 6 (WiFi) - allow software control */
> + if (reg == 6 && !(val_sw_override & BIT(6))) {
> + if (!(val_sw_disable & BIT(6))) {
> + val_sw_disable |= BIT(6);
> + writeb(val_sw_disable,
> + leds->regs + TURRIS1X_LED_SW_DISABLE_REG);
> + }
> + val_sw_override |= BIT(6);
> + writeb(val_sw_override,
> + leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG);
Again, is the register write that expensive that you try to avoid it if
the corresponding bit has the value you want?
> + }
> +
> + if (!(val_sw_override & BIT(reg)))
> + cdev->default_trigger = turris1x_hw_trigger.name;
> +
> + if (!(val_sw_override & BIT(reg)) || !(val_sw_disable & BIT(reg)))
> + cdev->brightness = LED_ON;
s/LED_ON/1/
> + ret = devm_led_classdev_multicolor_register_ext(dev, &led->mc_cdev,
> + &init_data);
> + if (ret) {
> + dev_err(dev, "Cannot register LED %pOF: %i\n", np, ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static ssize_t brightness_show(struct device *dev, struct device_attribute *a,
> + char *buf)
> +{
> + struct turris1x_leds *leds = dev_get_drvdata(dev);
> + unsigned int brightness;
> +
> + /*
> + * Current brightness value is available in read-only register
> + * TURRIS1X_LED_GET_GLOBAL_BRIGHTNESS_REG. Equivalent code is:
> + * level = readb(leds->regs + TURRIS1X_LED_GLOBAL_LEVEL_REG) & 7;
> + * brightness = readb(leds->regs + TURRIS1X_LED_GLOBAL_BRIGHTNESS_REG(level));
> + */
> + brightness = readb(leds->regs + TURRIS1X_LED_GET_GLOBAL_BRIGHTNESS_REG);
> +
> + return sprintf(buf, "%u\n", brightness);
> +}
> +
> +static ssize_t brightness_store(struct device *dev, struct device_attribute *a,
> + const char *buf, size_t count)
> +{
> + struct turris1x_leds *leds = dev_get_drvdata(dev);
> + int best_error, error, level, value;
> + unsigned long brightness;
> + u8 best_level;
> +
> + if (kstrtoul(buf, 10, &brightness))
> + return -EINVAL;
> +
> + if (brightness > 255)
> + return -EINVAL;
> +
> + /*
> + * Brightness can be set only to one of 8 predefined value levels
> + * available in TURRIS1X_LED_GLOBAL_BRIGHTNESS_REG(level) registers.
> + * Choose level which has nearest value to the specified brightness.
> + */
Hmm. Wouldn't it make more sense to simply have the global brightness
accept values from 0 to 7, instead of mapping it to 256 values? And
call it something like selected_brightness_index?
> + best_level = 0;
> + best_error = INT_MAX;
> + for (level = 0; level < 8; level++) {
> + value = readb(leds->regs +
> + TURRIS1X_LED_GLOBAL_BRIGHTNESS_REG(level));
> + error = abs(value - (int)brightness);
> + if (best_error > error) {
> + best_error = error;
> + best_level = level;
> + }
> + }
> +
> + writeb(best_level, leds->regs + TURRIS1X_LED_GLOBAL_LEVEL_REG);
> +
> + return count;
> +}
> +static DEVICE_ATTR_RW(brightness);
> +
> +static ssize_t brightness_values_show(struct device *dev,
> + struct device_attribute *a, char *buf)
> +{
> + struct turris1x_leds *leds = dev_get_drvdata(dev);
> + unsigned int vals[8];
> + int i;
> +
> + for (i = 0; i < 8; i++)
> + vals[i] = readb(leds->regs +
> + TURRIS1X_LED_GLOBAL_BRIGHTNESS_REG(i));
> +
> + return sprintf(buf, "%u %u %u %u %u %u %u %u\n", vals[0], vals[1],
> + vals[2], vals[3], vals[4], vals[5], vals[6], vals[7]);
> +}
> +
> +static ssize_t brightness_values_store(struct device *dev,
> + struct device_attribute *a,
> + const char *buf, size_t count)
> +{
> + struct turris1x_leds *leds = dev_get_drvdata(dev);
> + unsigned int vals[8];
> + int nchars;
> + int i;
> +
> + if (sscanf(buf, "%u %u %u %u %u %u %u %u%n", &vals[0], &vals[1],
> + &vals[2], &vals[3], &vals[4], &vals[5], &vals[6], &vals[7],
> + &nchars) != 8 || nchars + 1 < count)
> + return -EINVAL;
> +
> + for (i = 0; i < 8; i++)
> + writeb(vals[i],
> + leds->regs + TURRIS1X_LED_GLOBAL_BRIGHTNESS_REG(i));
> +
> + return count;
> +}
> +static DEVICE_ATTR_RW(brightness_values);
> +
> +static struct attribute *turris1x_leds_controller_attrs[] = {
> + &dev_attr_brightness.attr,
> + &dev_attr_brightness_values.attr,
> + NULL,
> +};
> +ATTRIBUTE_GROUPS(turris1x_leds_controller);
> +
> +static int turris1x_leds_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct device_node *np = dev_of_node(dev);
> + struct device_node *child;
> + struct turris1x_leds *leds;
> + struct resource *res;
> + void __iomem *regs;
> + u8 val_sw_override;
> + u8 val_sw_disable;
> + int ret;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res)
> + return -ENODEV;
> +
> + regs = devm_ioremap_resource(dev, res);
> + if (IS_ERR(regs))
> + return PTR_ERR(regs);
> +
> + leds = devm_kzalloc(dev, sizeof(*leds), GFP_KERNEL);
> + if (!leds)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, leds);
> +
> + leds->regs = regs;
> + mutex_init(&leds->lock);
> +
> + ret = devm_led_trigger_register(dev, &turris1x_hw_trigger);
> + if (ret) {
> + dev_err(dev, "Cannot register private LED trigger: %d\n", ret);
> + return ret;
> + }
> +
> + val_sw_override = readb(leds->regs + TURRIS1X_LED_SW_OVERRIDE_REG);
> + val_sw_disable = readb(leds->regs + TURRIS1X_LED_SW_DISABLE_REG);
> +
> + for_each_available_child_of_node(np, child) {
> + ret = turris1x_led_register(dev, leds, child,
> + val_sw_override, val_sw_disable);
> + if (ret) {
> + of_node_put(child);
> + return ret;
> + }
> + }
> +
> + ret = devm_device_add_groups(dev, turris1x_leds_controller_groups);
> + if (ret) {
> + dev_err(dev, "Could not add attribute group!\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static const struct of_device_id of_turris1x_leds_match[] = {
> + { .compatible = "cznic,turris1x-leds" },
> + {},
> +};
> +
> +static struct platform_driver turris1x_leds_driver = {
> + .probe = turris1x_leds_probe,
> + .driver = {
> + .name = "turris1x_leds",
> + .of_match_table = of_turris1x_leds_match,
> + },
> +};
> +module_platform_driver(turris1x_leds_driver);
> +
> +MODULE_AUTHOR("Pali Rohár <[email protected]>");
> +MODULE_DESCRIPTION("CZ.NIC's Turris 1.x LEDs");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:turris1x_leds");
On Tue, 5 Jul 2022 12:56:09 +0200
Pali Rohár <[email protected]> wrote:
> >
> > I don't consider this a problem
>
> I think it is a problem, to ensure that 'cat multi_intensity' for every
Misunderstanding. I meant that I don't consider the eventual
inconsistency a problem, i.e. I agree with your code.
> > Or maybe just write the value?
> > Is the register write expensive on the CPLD or why are you trying to
> > avoid it if unnecessary?
>
> I just do not see any reason to do unnecessary writes.
But now you do an unnecessary check. Unless the writeb() is slower than
that check. Since this isn't i2c, I am wondering how fast that writeb()
is... But this is just me wondering, we can keep it the way you wrote
it...
> >
> > Hmm. Wouldn't it make more sense to simply have the global brightness
> > accept values from 0 to 7, instead of mapping it to 256 values? And
> > call it something like selected_brightness_index?
>
> All other drivers have brightness entry which operates on monotone
> brightness property.
> Brightness levels do not have to be monotone and by default are
> decreasing: 0 = brightness with higher intensity; 7 = no intensity (off)
What do you mean all other drivers? AFAIK only one driver does this
global brightness thing, and that is Omnia. The global brightness is
something different from LED cdev brightness property, the same names
are just coincidental (in fact it caused confusion when Pavel was
first reviewing Turris Omnia driver). Maybe it should have been called
global_intensity, to avoid the confusion...
> I cannot image who would like or prefer usage of such API.
One file that represents the index of the selected global intensity (as
is stored internally in the CPLD) and another file that represents the
configured intensities between which the button switches makes sense,
IMO.
> Just stick with existing APIs. "brightness" entry takes intensity value
> which is monotone, 0 the lowest, MAX (=255) the highest.
Again, the name "brightness" does not imply that it is the same thing
as "brightness" of a LED cdev. And since it even doesn't live in
/sys/class/<led>/ directory, we are proposing new API and can use
whatever makes sense.
I am not saying that the way you did it doesn't make sense. I am just
wondering if it wouldn't make more sense to be able to read the index
of what the user selected by button pressing.
Marek
On Tuesday 05 July 2022 13:52:27 Marek Behún wrote:
> On Tue, 5 Jul 2022 12:56:09 +0200
> Pali Rohár <[email protected]> wrote:
>
> > >
> > > I don't consider this a problem
> >
> > I think it is a problem, to ensure that 'cat multi_intensity' for every
>
> Misunderstanding. I meant that I don't consider the eventual
> inconsistency a problem, i.e. I agree with your code.
>
> > > Or maybe just write the value?
> > > Is the register write expensive on the CPLD or why are you trying to
> > > avoid it if unnecessary?
> >
> > I just do not see any reason to do unnecessary writes.
>
> But now you do an unnecessary check.
I think that testing if some bit is set in 32-bit general purpose
processor register is something which really does not play role here.
Note that readb() is always needed to do because it is required to
modify just one bit and this cannot be done without read-modify-write
operations.
> Unless the writeb() is slower than
> that check. Since this isn't i2c, I am wondering how fast that writeb()
> is... But this is just me wondering, we can keep it the way you wrote
> it...
>
> > >
> > > Hmm. Wouldn't it make more sense to simply have the global brightness
> > > accept values from 0 to 7, instead of mapping it to 256 values? And
> > > call it something like selected_brightness_index?
> >
> > All other drivers have brightness entry which operates on monotone
> > brightness property.
> > Brightness levels do not have to be monotone and by default are
> > decreasing: 0 = brightness with higher intensity; 7 = no intensity (off)
>
> What do you mean all other drivers? AFAIK only one driver does this
> global brightness thing, and that is Omnia. The global brightness is
> something different from LED cdev brightness property, the same names
> are just coincidental (in fact it caused confusion when Pavel was
> first reviewing Turris Omnia driver). Maybe it should have been called
> global_intensity, to avoid the confusion...
Ok. I thought "brightness" == "brightness" too.
Anyway, as Omnia has this API it makes sense to use same API for other
devices, this allows userspace software to be compatible with more
devices.
> > I cannot image who would like or prefer usage of such API.
>
> One file that represents the index of the selected global intensity (as
> is stored internally in the CPLD) and another file that represents the
> configured intensities between which the button switches makes sense,
> IMO.
And this is the issue. If you want to get current brightness, you need
to read two files and then do non-trivial logic to derive current
brightness.
> > Just stick with existing APIs. "brightness" entry takes intensity value
> > which is monotone, 0 the lowest, MAX (=255) the highest.
>
> Again, the name "brightness" does not imply that it is the same thing
> as "brightness" of a LED cdev. And since it even doesn't live in
> /sys/class/<led>/ directory, we are proposing new API and can use
> whatever makes sense.
>
> I am not saying that the way you did it doesn't make sense. I am just
> wondering if it wouldn't make more sense to be able to read the index
> of what the user selected by button pressing.
>
> Marek
So what about exporting another sysfs file which controls current level (0-7)?
On Tue, 5 Jul 2022 14:32:06 +0200
Pali Rohár <[email protected]> wrote:
> On Tuesday 05 July 2022 14:30:01 Marek Behún wrote:
> > On Tue, 5 Jul 2022 14:22:38 +0200
> > Pali Rohár <[email protected]> wrote:
> > > So what about exporting another sysfs file which controls current level (0-7)?
> >
> > OK, that would be satisfactory. Something like
> > "selected_brightness_index".
>
> Too long? What about just "brightness_level" and make it R/W?
> We already call it level (not index).
ok
On Tue, 5 Jul 2022 14:22:38 +0200
Pali Rohár <[email protected]> wrote:
> On Tuesday 05 July 2022 13:52:27 Marek Behún wrote:
> > On Tue, 5 Jul 2022 12:56:09 +0200
> > Pali Rohár <[email protected]> wrote:
> >
> > > >
> > > > I don't consider this a problem
> > >
> > > I think it is a problem, to ensure that 'cat multi_intensity' for every
> >
> > Misunderstanding. I meant that I don't consider the eventual
> > inconsistency a problem, i.e. I agree with your code.
> >
> > > > Or maybe just write the value?
> > > > Is the register write expensive on the CPLD or why are you trying to
> > > > avoid it if unnecessary?
> > >
> > > I just do not see any reason to do unnecessary writes.
> >
> > But now you do an unnecessary check.
>
> I think that testing if some bit is set in 32-bit general purpose
> processor register is something which really does not play role here.
>
> Note that readb() is always needed to do because it is required to
> modify just one bit and this cannot be done without read-modify-write
> operations.
>
> > Unless the writeb() is slower than
> > that check. Since this isn't i2c, I am wondering how fast that writeb()
> > is... But this is just me wondering, we can keep it the way you wrote
> > it...
> >
> > > >
> > > > Hmm. Wouldn't it make more sense to simply have the global brightness
> > > > accept values from 0 to 7, instead of mapping it to 256 values? And
> > > > call it something like selected_brightness_index?
> > >
> > > All other drivers have brightness entry which operates on monotone
> > > brightness property.
> > > Brightness levels do not have to be monotone and by default are
> > > decreasing: 0 = brightness with higher intensity; 7 = no intensity (off)
> >
> > What do you mean all other drivers? AFAIK only one driver does this
> > global brightness thing, and that is Omnia. The global brightness is
> > something different from LED cdev brightness property, the same names
> > are just coincidental (in fact it caused confusion when Pavel was
> > first reviewing Turris Omnia driver). Maybe it should have been called
> > global_intensity, to avoid the confusion...
>
> Ok. I thought "brightness" == "brightness" too.
>
> Anyway, as Omnia has this API it makes sense to use same API for other
> devices, this allows userspace software to be compatible with more
> devices.
>
> > > I cannot image who would like or prefer usage of such API.
> >
> > One file that represents the index of the selected global intensity (as
> > is stored internally in the CPLD) and another file that represents the
> > configured intensities between which the button switches makes sense,
> > IMO.
>
> And this is the issue. If you want to get current brightness, you need
> to read two files and then do non-trivial logic to derive current
> brightness.
>
> > > Just stick with existing APIs. "brightness" entry takes intensity value
> > > which is monotone, 0 the lowest, MAX (=255) the highest.
> >
> > Again, the name "brightness" does not imply that it is the same thing
> > as "brightness" of a LED cdev. And since it even doesn't live in
> > /sys/class/<led>/ directory, we are proposing new API and can use
> > whatever makes sense.
> >
> > I am not saying that the way you did it doesn't make sense. I am just
> > wondering if it wouldn't make more sense to be able to read the index
> > of what the user selected by button pressing.
> >
> > Marek
>
> So what about exporting another sysfs file which controls current level (0-7)?
OK, that would be satisfactory. Something like
"selected_brightness_index".
Marek
On Tuesday 05 July 2022 14:30:01 Marek Behún wrote:
> On Tue, 5 Jul 2022 14:22:38 +0200
> Pali Rohár <[email protected]> wrote:
> > So what about exporting another sysfs file which controls current level (0-7)?
>
> OK, that would be satisfactory. Something like
> "selected_brightness_index".
Too long? What about just "brightness_level" and make it R/W?
We already call it level (not index).