The Broadcom BCA (Broadband Access) SoCs have a LED control
block that can support either parallel (directly connected)
LEDs or serial (connected to 1-4 shift registers) LEDs.
Add a driver for that hardware.
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
MAINTAINERS | 7 +
drivers/leds/Kconfig | 9 ++
drivers/leds/Makefile | 1 +
drivers/leds/leds-bcmbca.c | 391 +++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 408 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index cc40a9d9b8cd..0a603b72a6a0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4383,6 +4383,13 @@ N: bcm[9]?6856
N: bcm[9]?6858
N: bcm[9]?6878
+BROADCOM BCMBCA LED DRIVER
+M: Linus Walleij <linus.walleij@xxxxxxxxxx>
+L: linux-leds@xxxxxxxxxxxxxxx
+S: Maintained
+F: Documentation/devicetree/bindings/leds/brcm,bcmbca-leds.yaml
+F: drivers/leds/leds-bcmbca.c
+
BROADCOM BDC DRIVER
M: Justin Chen <justin.chen@xxxxxxxxxxxx>
M: Al Cooper <alcooperx@xxxxxxxxx>
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 8d9d8da376e4..e14c7fa587f0 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -146,6 +146,15 @@ config LEDS_BCM6358
This option enables support for LEDs connected to the BCM6358
LED HW controller accessed via MMIO registers.
+config LEDS_BCMBCA
+ tristate "LED Support for Broadcom BCMBCA"
+ depends on LEDS_CLASS
+ depends on HAS_IOMEM
+ depends on OF
+ help
+ This option enables support for LEDs connected to the BCMBCA
+ LED HW controller accessed via MMIO registers.
+
config LEDS_CHT_WCOVE
tristate "LED support for Intel Cherry Trail Whiskey Cove PMIC"
depends on LEDS_CLASS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 18afbb5a23ee..96e036f04e18 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_LEDS_AW200XX) += leds-aw200xx.o
obj-$(CONFIG_LEDS_AW2013) += leds-aw2013.o
obj-$(CONFIG_LEDS_BCM6328) += leds-bcm6328.o
obj-$(CONFIG_LEDS_BCM6358) += leds-bcm6358.o
+obj-$(CONFIG_LEDS_BCMBCA) += leds-bcmbca.o
obj-$(CONFIG_LEDS_BD2606MVV) += leds-bd2606mvv.o
obj-$(CONFIG_LEDS_BD2802) += leds-bd2802.o
obj-$(CONFIG_LEDS_BLINKM) += leds-blinkm.o
diff --git a/drivers/leds/leds-bcmbca.c b/drivers/leds/leds-bcmbca.c
new file mode 100644
index 000000000000..74dc4245bea4
--- /dev/null
+++ b/drivers/leds/leds-bcmbca.c
@@ -0,0 +1,391 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Driver for BCMBCA memory-mapped LEDs
+ *
+ * Copyright 2024 Linus Walleij <linus.walleij@xxxxxxxxxx>
+ */
+#include <linux/bits.h>
+#include <linux/cleanup.h>
+#include <linux/io.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+
+#define BCMBCA_CTRL 0x00
+#define BCMBCA_CTRL_SERIAL_POL_HIGH BIT(1)
+#define BCMBCA_CTRL_ENABLE BIT(3) /* Uncertain about this bit */
+#define BCMBCA_CTRL_SERIAL_MSB_FIRST BIT(4)
+
+#define BCMBCA_MASK 0x04
+#define BCMBCA_HW_EN 0x08
+/*
+ * In the serial shift selector, set bits to 1 from BIT(0) and upward all
+ * set to one until the last LED including any unused slots in the shift
+ * register.
+ */
+#define BCMBCA_SERIAL_SHIFT_SEL 0x0c
+#define BCMBCA_FLASH_RATE 0x10 /* 4 bits per LED so -> 1c */
+#define BCMBCA_BRIGHTNESS 0x20 /* 4 bits per LED so -> 2c */
+#define BCMBCA_POWER_LED_CFG 0x30
+#define BCMBCA_POWER_LUT 0x34 /* -> b0 */
+#define BCMBCA_HW_POLARITY 0xb4
+#define BCMBCA_SW_DATA 0xb8 /* 1 bit on/off for each LED */
+#define BCMBCA_SW_POLARITY 0xbc
+#define BCMBCA_PARALLEL_POLARITY 0xc0
+#define BCMBCA_SERIAL_POLARITY 0xc4
+
+#define BCMBCA_LED_MAX_COUNT 32
+#define BCMBCA_LED_MAX_BRIGHTNESS 8
+
+enum bcmbca_led_type {
+ BCMBCA_LED_SERIAL,
+ BCMBCA_LED_PARALLEL,
+};
+
+/**
+ * struct bcmbca_led - state container for bcmbca based LEDs
+ * @cdev: LED class device for this LED
+ * @base: memory base address
+ * @lock: memory lock
+ * @idx: LED index number
+ * @active_low: LED is active low
+ * @num_serial_shifters: number of serial shift registers
+ * @led_type: whether this is a serial or parallel LED
+ */
+struct bcmbca_led {
+ struct led_classdev cdev;
+ void __iomem *base;
+ spinlock_t *lock;
+ unsigned int idx;
+ bool active_low;
+ u32 num_serial_shifters;
+ enum bcmbca_led_type led_type;
+};
+
+static void bcmbca_led_blink_disable(struct led_classdev *ldev)
+{
+ struct bcmbca_led *led =
+ container_of(ldev, struct bcmbca_led, cdev);
+ /* 8 LEDs per register so integer-divide by 8 */
+ u8 led_offset = (led->idx >> 3);
+ /* Find the 4 bits for each LED */
+ u32 led_mask = 0xf << ((led->idx & 0x07) << 2);
+ u32 val;
+
+ /* Write registers */
+ guard(spinlock_irqsave)(led->lock);
+ val = readl(led->base + BCMBCA_FLASH_RATE + led_offset);
+ val &= led_mask;
+ writel(val, led->base + BCMBCA_FLASH_RATE + led_offset);
+}
+
+static int bcmbca_led_blink_set(struct led_classdev *ldev,
+ unsigned long *delay_on,
+ unsigned long *delay_off)
+{
+ struct bcmbca_led *led =
+ container_of(ldev, struct bcmbca_led, cdev);
+ u8 led_offset = (led->idx >> 3);
+ u32 led_mask = 0xf << ((led->idx & 0x07) << 2);
+ unsigned long period;
+ u32 led_val;
+ u32 val;
+
+ /* Friendly defaults as specified in the documentation */
+ if (*delay_on == 0 && *delay_off == 0) {
+ *delay_on = 240;
+ *delay_off = 240;
+ }
+
+ if (*delay_on != *delay_off) {
+ dev_dbg(ldev->dev, "only square blink supported\n");
+ return -EINVAL;
+ }
+
+ period = *delay_on + *delay_off;
+ if (period > 2000) {
+ dev_dbg(ldev->dev, "period too long, %lu max 2000 ms\n",
+ period);
+ return -EINVAL;
+ }
+
+ if (period <= 60)
+ led_val = 1;
+ else if (period <= 120)
+ led_val = 2;
+ else if (period <= 240)
+ led_val = 3;
+ else if (period <= 480)
+ led_val = 4;
+ else if (period <= 960)
+ led_val = 5;
+ else if (period <= 1920)
+ led_val = 6;
+ else
+ led_val = 7;
+
+ led_val = led_val << ((led->idx & 0x07) << 2);
+
+ /* Write registers */
+ guard(spinlock_irqsave)(led->lock);
+ val = readl(led->base + BCMBCA_FLASH_RATE + led_offset);
+ val &= led_mask;
+ val |= led_val;
+ writel(val, led->base + BCMBCA_FLASH_RATE + led_offset);
+
+ return 0;
+}
+
+static void bcmbca_led_set(struct led_classdev *ldev,
+ enum led_brightness value)
+{
+ struct bcmbca_led *led =
+ container_of(ldev, struct bcmbca_led, cdev);
+ u8 led_offset = (led->idx >> 3);
+ u32 led_mask = 0xf << ((led->idx & 0x07) << 2);
+ u32 led_val = value << ((led->idx & 0x07) << 2);
+ u32 val;
+
+ dev_dbg(ldev->dev, "LED%u, register %08x, mask %08x, value %08x\n",
+ led->idx, BCMBCA_BRIGHTNESS + led_offset, led_mask, led_val);
+
+ /* Write registers */
+ guard(spinlock_irqsave)(led->lock);
+
+ /* Parallel LEDs support brightness control */
+ if (led->led_type == BCMBCA_LED_PARALLEL) {
+ val = readl(led->base + BCMBCA_BRIGHTNESS + led_offset);
+ val &= led_mask;
+ val |= led_val;
+ writel(val, led->base + BCMBCA_BRIGHTNESS + led_offset);
+ }
+
+ /* Software control on/off */
+ if (value == LED_OFF) {
+ val = readl(led->base + BCMBCA_SW_DATA);
+ val &= ~BIT(led->idx);
+ writel(val, led->base + BCMBCA_SW_DATA);
+ bcmbca_led_blink_disable(ldev);
+ } else {
+ val = readl(led->base + BCMBCA_SW_DATA);
+ val |= BIT(led->idx);
+ writel(val, led->base + BCMBCA_SW_DATA);
+ }
+}
+
+static u8 bcmbca_led_get(void __iomem *base, int idx)
+{
+ u8 led_offset = (idx >> 3);
+ u32 led_mask = 0xf << ((idx & 0x07) << 2);
+ u32 val;
+
+ /* Called marshalled so no lock needed */
+ val = readl(base + BCMBCA_BRIGHTNESS + led_offset);
+ return ((val & led_mask) >> ((idx & 0x07) << 2));
+}
+
+static int bcmbca_led_probe(struct device *dev, struct device_node *np, u32 reg,
+ void __iomem *base, spinlock_t *lock,
+ u32 num_shifters, enum bcmbca_led_type led_type)
+{
+ struct led_init_data init_data = {};
+ struct bcmbca_led *led;
+ enum led_default_state state;
+ u32 val;
+ int rc;
+
+ led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
+ if (!led)
+ return -ENOMEM;
+
+ led->idx = reg;
+ led->base = base;
+ led->lock = lock;
+
+ if (of_property_read_bool(np, "active-low"))
+ led->active_low = true;
+
+ init_data.fwnode = of_fwnode_handle(np);
+
+ if (led->led_type == BCMBCA_LED_PARALLEL)
+ led->cdev.max_brightness = BCMBCA_LED_MAX_BRIGHTNESS;
+ else
+ led->cdev.max_brightness = LED_ON;
+
+ state = led_init_default_state_get(init_data.fwnode);
+
+ switch (state) {
+ case LEDS_DEFSTATE_ON:
+ led->cdev.brightness = led->cdev.max_brightness;
+ break;
+ case LEDS_DEFSTATE_KEEP:
+ val = bcmbca_led_get(base, led->idx);
+ if (val)
+ led->cdev.brightness = val;
+ else
+ led->cdev.brightness = LED_OFF;
+ break;
+ default:
+ led->cdev.brightness = LED_OFF;
+ break;
+ }
+
+ /*
+ * Polarity inversion setting per-LED
+ * The default is actually active low, we set a bit to 1
+ * in the register to make it active high.
+ */
+ if (!of_property_read_bool(np, "active-low")) {
+ switch (led_type) {
+ case BCMBCA_LED_SERIAL:
+ val = readl(base + BCMBCA_SERIAL_POLARITY);
+ val |= BIT(led->idx);
+ writel(val, base + BCMBCA_SERIAL_POLARITY);
+ break;
+ case BCMBCA_LED_PARALLEL:
+ val = readl(base + BCMBCA_PARALLEL_POLARITY);
+ val |= BIT(led->idx);
+ writel(val, base + BCMBCA_PARALLEL_POLARITY);
+ break;
+ default:
+ break;
+ }
+ }
+
+ /* Initial brightness setup */
+ bcmbca_led_set(&led->cdev, led->cdev.brightness);
+
+ led->cdev.brightness_set = bcmbca_led_set;
+ led->cdev.blink_set = bcmbca_led_blink_set;
+ /* TODO: implement HW control */
+
+ rc = devm_led_classdev_register_ext(dev, &led->cdev, &init_data);
+ if (rc < 0)
+ return rc;
+
+ dev_info(dev, "registered LED %s\n", led->cdev.name);
+
+ return 0;
+}
+
+static int bcmbca_leds_probe(struct platform_device *pdev)
+{
+ unsigned int max_leds = BCMBCA_LED_MAX_COUNT;
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev_of_node(&pdev->dev);
+ enum bcmbca_led_type led_type;
+ void __iomem *base;
+ spinlock_t *lock; /* memory lock */
+ u32 num_shifters;
+ u32 val;
+ int ret;
+ int i;
+
+ base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL);
+ if (!lock)
+ return -ENOMEM;
+
+ ret = of_property_read_u32(np, "brcm,serial-shifters", &num_shifters);
+ if (!ret) {
+ /* Serial LEDs */
+ dev_dbg(dev, "serial LEDs, %d shift registers used\n", num_shifters);
+ led_type = BCMBCA_LED_SERIAL;
+ /*
+ * Each shifter can handle maximum 8 LEDs so we cap the
+ * maximum LEDs we can handle at that.
+ */
+ max_leds = num_shifters * 8;
+ } else {
+ /* Parallel LEDs */
+ led_type = BCMBCA_LED_PARALLEL;
+ dev_info(dev, "parallel LEDs requested, this is untested\n");
+ }
+
+ spin_lock_init(lock);
+
+ /* Turn off all LEDs and let the driver deal with them */
+ writel(0, base + BCMBCA_HW_EN);
+ writel(0, base + BCMBCA_SERIAL_POLARITY);
+ writel(0, base + BCMBCA_PARALLEL_POLARITY);
+
+ /* Set up serial shift register */
+ switch (num_shifters) {
+ case 0:
+ val = 0;
+ break;
+ case 1:
+ val = 0x000000ff;
+ break;
+ case 2:
+ val = 0x0000ffff;
+ break;
+ case 3:
+ val = 0x00ffffff;
+ break;
+ case 4:
+ val = 0xffffffff;
+ break;
+ }
+ writel(val, base + BCMBCA_SERIAL_SHIFT_SEL);
+
+ /* ??? */
+ writel(0xc0000000, base + BCMBCA_HW_POLARITY);
+ /* Initialize to max brightness */
+ for (i = 0; i < BCMBCA_LED_MAX_COUNT/8; i++) {
+ writel(0x88888888, base + BCMBCA_BRIGHTNESS + 4*i);
+ writel(0, base + BCMBCA_BRIGHTNESS + BCMBCA_FLASH_RATE + 4*i);
+ }
+
+ for_each_available_child_of_node_scoped(np, child) {
+ u32 reg;
+
+ if (of_property_read_u32(child, "reg", ®))
+ continue;
+
+ if (reg >= max_leds) {
+ dev_err(dev, "invalid LED (%u >= %d)\n", reg,
+ max_leds);
+ continue;
+ }
+
+ ret = bcmbca_led_probe(dev, child, reg, base, lock,
+ num_shifters, led_type);
+ if (ret < 0)
+ return ret;
+ }
+
+ /* Enable the LEDs */
+ val = BCMBCA_CTRL_ENABLE | BCMBCA_CTRL_SERIAL_POL_HIGH;
+ if (of_property_read_bool(np, "brcm,serial-active-low"))
+ val &= ~BCMBCA_CTRL_SERIAL_POL_HIGH;
+ writel(val, base + BCMBCA_CTRL);
+
+ return 0;
+}
+
+static const struct of_device_id bcmbca_leds_of_match[] = {
+ { .compatible = "brcm,bcmbca-leds", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, bcmbca_leds_of_match);
+
+static struct platform_driver bcmbca_leds_driver = {
+ .probe = bcmbca_leds_probe,
+ .driver = {
+ .name = "leds-bcmbca",
+ .of_match_table = bcmbca_leds_of_match,
+ },
+};
+
+module_platform_driver(bcmbca_leds_driver);
+
+MODULE_AUTHOR("Linus Walleij <linus.walleij@xxxxxxxxxx>");
+MODULE_DESCRIPTION("LED driver for BCMBCA LED controllers");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:leds-bcmbca");
--
2.46.0
