[PATCH net-next v2 2/2] net: dsa: mt7530: MT7530 optional GPIO support

DENG Qingfang
2021-01-25T04:45:07Z

MT7530's LED controller can drive up to 15 LED/GPIOs.

Add support for GPIO control and allow users to use its GPIOs by
setting gpio-controller property in device tree.

Signed-off-by: DENG Qingfang <dqfext@gmail.com>
---
Changes v1 -> v2:

Set Output Enable after changing direction to output to avoid signal
glitch.
Comment mt7530_gpio_to_bit function.

drivers/net/dsa/mt7530.c | 110 +++++++++++++++++++++++++++++++++++++++
drivers/net/dsa/mt7530.h | 20 +++++++
2 files changed, 130 insertions(+)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index d2196197d920..eb13ba79dd01 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -18,6 +18,7 @@
#include <linux/regulator/consumer.h>
#include <linux/reset.h>
#include <linux/gpio/consumer.h>
+#include <linux/gpio/driver.h>
#include <net/dsa.h>

#include "mt7530.h"
@@ -1622,6 +1623,109 @@ mtk_get_tag_protocol(struct dsa_switch *ds, int port,
}
}

+static inline u32
+mt7530_gpio_to_bit(unsigned int offset)
+{
+ /* Map GPIO offset to register bit
+ * [ 2: 0] port 0 LED 0..2 as GPIO 0..2
+ * [ 6: 4] port 1 LED 0..2 as GPIO 3..5
+ * [10: 8] port 2 LED 0..2 as GPIO 6..8
+ * [14:12] port 3 LED 0..2 as GPIO 9..11
+ * [18:16] port 4 LED 0..2 as GPIO 12..14
+ */
+ return BIT(offset + offset / 3);
+}
+
+static int
+mt7530_gpio_get(struct gpio_chip *gc, unsigned int offset)
+{
+ struct mt7530_priv *priv = gpiochip_get_data(gc);
+ u32 bit = mt7530_gpio_to_bit(offset);
+
+ return !!(mt7530_read(priv, MT7530_LED_GPIO_DATA) & bit);
+}
+
+static void
+mt7530_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
+{
+ struct mt7530_priv *priv = gpiochip_get_data(gc);
+ u32 bit = mt7530_gpio_to_bit(offset);
+
+ if (value)
+ mt7530_set(priv, MT7530_LED_GPIO_DATA, bit);
+ else
+ mt7530_clear(priv, MT7530_LED_GPIO_DATA, bit);
+}
+
+static int
+mt7530_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+ struct mt7530_priv *priv = gpiochip_get_data(gc);
+ u32 bit = mt7530_gpio_to_bit(offset);
+
+ return (mt7530_read(priv, MT7530_LED_GPIO_DIR) & bit) ?
+ GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
+}
+
+static int
+mt7530_gpio_direction_input(struct gpio_chip *gc, unsigned int offset)
+{
+ struct mt7530_priv *priv = gpiochip_get_data(gc);
+ u32 bit = mt7530_gpio_to_bit(offset);
+
+ mt7530_clear(priv, MT7530_LED_GPIO_OE, bit);
+ mt7530_clear(priv, MT7530_LED_GPIO_DIR, bit);
+
+ return 0;
+}
+
+static int
+mt7530_gpio_direction_output(struct gpio_chip *gc, unsigned int offset, int value)
+{
+ struct mt7530_priv *priv = gpiochip_get_data(gc);
+ u32 bit = mt7530_gpio_to_bit(offset);
+
+ mt7530_set(priv, MT7530_LED_GPIO_DIR, bit);
+
+ if (value)
+ mt7530_set(priv, MT7530_LED_GPIO_DATA, bit);
+ else
+ mt7530_clear(priv, MT7530_LED_GPIO_DATA, bit);
+
+ mt7530_set(priv, MT7530_LED_GPIO_OE, bit);
+
+ return 0;
+}
+
+static int
+mt7530_setup_gpio(struct mt7530_priv *priv)
+{
+ struct device *dev = priv->dev;
+ struct gpio_chip *gc;
+
+ gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
+ if (!gc)
+ return -ENOMEM;
+
+ mt7530_write(priv, MT7530_LED_GPIO_OE, 0);
+ mt7530_write(priv, MT7530_LED_GPIO_DIR, 0);
+ mt7530_write(priv, MT7530_LED_IO_MODE, 0);
+
+ gc->label = "mt7530";
+ gc->parent = dev;
+ gc->owner = THIS_MODULE;
+ gc->get_direction = mt7530_gpio_get_direction;
+ gc->direction_input = mt7530_gpio_direction_input;
+ gc->direction_output = mt7530_gpio_direction_output;
+ gc->get = mt7530_gpio_get;
+ gc->set = mt7530_gpio_set;
+ gc->base = -1;
+ gc->ngpio = 15;
+ gc->can_sleep = true;
+
+ return devm_gpiochip_add_data(dev, gc, priv);
+}
+
static int
mt7530_setup(struct dsa_switch *ds)
{
@@ -1763,6 +1867,12 @@ mt7530_setup(struct dsa_switch *ds)
}
}

+ if (of_property_read_bool(priv->dev->of_node, "gpio-controller")) {
+ ret = mt7530_setup_gpio(priv);
+ if (ret)
+ return ret;
+ }
+
mt7530_setup_port5(ds, interface);

/* Flush the FDB table */
diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h
index 32d8969b3ace..64a9bb377e15 100644
--- a/drivers/net/dsa/mt7530.h
+++ b/drivers/net/dsa/mt7530.h
@@ -554,6 +554,26 @@ enum mt7531_clk_skew {
#define MT7531_GPIO12_RG_RXD3_MASK GENMASK(19, 16)
#define MT7531_EXT_P_MDIO_12 (2 << 16)

+/* Registers for LED GPIO control (MT7530 only)
+ * All registers follow this pattern:
+ * [ 2: 0] port 0
+ * [ 6: 4] port 1
+ * [10: 8] port 2
+ * [14:12] port 3
+ * [18:16] port 4
+ */
+
+/* LED enable, 0: Disable, 1: Enable (Default) */
+#define MT7530_LED_EN 0x7d00
+/* LED mode, 0: GPIO mode, 1: PHY mode (Default) */
+#define MT7530_LED_IO_MODE 0x7d04
+/* GPIO direction, 0: Input, 1: Output */
+#define MT7530_LED_GPIO_DIR 0x7d10
+/* GPIO output enable, 0: Disable, 1: Enable */
+#define MT7530_LED_GPIO_OE 0x7d14
+/* GPIO value, 0: Low, 1: High */
+#define MT7530_LED_GPIO_DATA 0x7d18
+
#define MT7530_CREV 0x7ffc
#define CHIP_NAME_SHIFT 16
#define MT7530_ID 0x7530
--
2.25.1