mfd: vexpress: Add pseudo-GPIO based LEDs

The LEDs on the Versatile Express motherboard are controlled
through simple memory-mapped register. This patch extends
the pseudo-GPIO controller definition for these lines and
creates generic "leds-gpio" device using them

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

2 files changed, 63 insertions, 18 deletions

diff --git a/drivers/mfd/vexpress-sysreg.c b/drivers/mfd/vexpress-sysreg.c
index 77048b18439e..51c3ca263bf5 100644
--- a/drivers/mfd/vexpress-sysreg.c
+++ b/drivers/mfd/vexpress-sysreg.c
@@ -49,6 +49,8 @@
 #define SYS_ID_HBI_SHIFT        16
 #define SYS_PROCIDx_HBI_SHIFT   0
 
+#define SYS_LED_LED(n)          (1 << (n))
+
 #define SYS_MCI_CARDIN          (1 << 0)
 #define SYS_MCI_WPROT           (1 << 1)
 
@@ -348,22 +350,27 @@ void __init vexpress_sysreg_of_early_init(void)
 }
 
 
+#define VEXPRESS_SYSREG_GPIO(_name, _reg, _value) \
+        [VEXPRESS_GPIO_##_name] = { \
+                .reg = _reg, \
+                .value = _reg##_##_value, \
+        }
+
 static struct vexpress_sysreg_gpio {
         unsigned long reg;
         u32 value;
 } vexpress_sysreg_gpios[] = {
-        [VEXPRESS_GPIO_MMC_CARDIN] = {
-                .reg = SYS_MCI,
-                .value = SYS_MCI_CARDIN,
-        },
-        [VEXPRESS_GPIO_MMC_WPROT] = {
-                .reg = SYS_MCI,
-                .value = SYS_MCI_WPROT,
-        },
-        [VEXPRESS_GPIO_FLASH_WPn] = {
-                .reg = SYS_FLASH,
-                .value = SYS_FLASH_WPn,
-        },
+        VEXPRESS_SYSREG_GPIO(MMC_CARDIN,        SYS_MCI,        CARDIN),
+        VEXPRESS_SYSREG_GPIO(MMC_WPROT,         SYS_MCI,        WPROT),
+        VEXPRESS_SYSREG_GPIO(FLASH_WPn,         SYS_FLASH,      WPn),
+        VEXPRESS_SYSREG_GPIO(LED0,              SYS_LED,        LED(0)),
+        VEXPRESS_SYSREG_GPIO(LED1,              SYS_LED,        LED(1)),
+        VEXPRESS_SYSREG_GPIO(LED2,              SYS_LED,        LED(2)),
+        VEXPRESS_SYSREG_GPIO(LED3,              SYS_LED,        LED(3)),
+        VEXPRESS_SYSREG_GPIO(LED4,              SYS_LED,        LED(4)),
+        VEXPRESS_SYSREG_GPIO(LED5,              SYS_LED,        LED(5)),
+        VEXPRESS_SYSREG_GPIO(LED6,              SYS_LED,        LED(6)),
+        VEXPRESS_SYSREG_GPIO(LED7,              SYS_LED,        LED(7)),
 };
 
 static int vexpress_sysreg_gpio_direction_input(struct gpio_chip *chip,
@@ -372,12 +379,6 @@ static int vexpress_sysreg_gpio_direction_input(struct gpio_chip *chip,
         return 0;
 }
 
-static int vexpress_sysreg_gpio_direction_output(struct gpio_chip *chip,
-                                                unsigned offset, int value)
-{
-        return 0;
-}
-
 static int vexpress_sysreg_gpio_get(struct gpio_chip *chip,
                                        unsigned offset)
 {
@@ -401,6 +402,14 @@ static void vexpress_sysreg_gpio_set(struct gpio_chip *chip,
         writel(reg_value, vexpress_sysreg_base + gpio->reg);
 }
 
+static int vexpress_sysreg_gpio_direction_output(struct gpio_chip *chip,
+                                                unsigned offset, int value)
+{
+        vexpress_sysreg_gpio_set(chip, offset, value);
+
+        return 0;
+}
+
 static struct gpio_chip vexpress_sysreg_gpio_chip = {
         .label = "vexpress-sysreg",
         .direction_input = vexpress_sysreg_gpio_direction_input,
@@ -412,6 +421,30 @@ static struct gpio_chip vexpress_sysreg_gpio_chip = {
 };
 
 
+#define VEXPRESS_SYSREG_GREEN_LED(_name, _default_trigger, _gpio) \
+        { \
+                .name = "v2m:green:"_name, \
+                .default_trigger = _default_trigger, \
+                .gpio = VEXPRESS_GPIO_##_gpio, \
+        }
+
+struct gpio_led vexpress_sysreg_leds[] = {
+        VEXPRESS_SYSREG_GREEN_LED("user1",      "heartbeat",    LED0),
+        VEXPRESS_SYSREG_GREEN_LED("user2",      "mmc0",         LED1),
+        VEXPRESS_SYSREG_GREEN_LED("user3",      "cpu0",         LED2),
+        VEXPRESS_SYSREG_GREEN_LED("user4",      "cpu1",         LED3),
+        VEXPRESS_SYSREG_GREEN_LED("user5",      "cpu2",         LED4),
+        VEXPRESS_SYSREG_GREEN_LED("user6",      "cpu3",         LED5),
+        VEXPRESS_SYSREG_GREEN_LED("user7",      "cpu4",         LED6),
+        VEXPRESS_SYSREG_GREEN_LED("user8",      "cpu5",         LED7),
+};
+
+struct gpio_led_platform_data vexpress_sysreg_leds_pdata = {
+        .num_leds = ARRAY_SIZE(vexpress_sysreg_leds),
+        .leds = vexpress_sysreg_leds,
+};
+
+
 static ssize_t vexpress_sysreg_sys_id_show(struct device *dev,
                 struct device_attribute *attr, char *buf)
 {
@@ -456,6 +489,10 @@ static int vexpress_sysreg_probe(struct platform_device *pdev)
                 return err;
         }
 
+        platform_device_register_data(vexpress_sysreg_dev, "leds-gpio",
+                        PLATFORM_DEVID_AUTO, &vexpress_sysreg_leds_pdata,
+                        sizeof(vexpress_sysreg_leds_pdata));
+
         vexpress_sysreg_dev = &pdev->dev;
 
         device_create_file(vexpress_sysreg_dev, &dev_attr_sys_id);
diff --git a/include/linux/vexpress.h b/include/linux/vexpress.h
index c52215ff4245..75818744ab59 100644
--- a/include/linux/vexpress.h
+++ b/include/linux/vexpress.h
@@ -27,6 +27,14 @@
 #define VEXPRESS_GPIO_MMC_CARDIN        0
 #define VEXPRESS_GPIO_MMC_WPROT         1
 #define VEXPRESS_GPIO_FLASH_WPn         2
+#define VEXPRESS_GPIO_LED0              3
+#define VEXPRESS_GPIO_LED1              4
+#define VEXPRESS_GPIO_LED2              5
+#define VEXPRESS_GPIO_LED3              6
+#define VEXPRESS_GPIO_LED4              7
+#define VEXPRESS_GPIO_LED5              8
+#define VEXPRESS_GPIO_LED6              9
+#define VEXPRESS_GPIO_LED7              10
 
 #define VEXPRESS_RES_FUNC(_site, _func) \
 {                                       \