@@ -4,9 +4,11 @@
* datasheet: http://www.ti.com/lit/ds/symlink/sn65dsi86.pdf
*/
+#include <linux/bits.h>
#include <linux/clk.h>
#include <linux/debugfs.h>
#include <linux/gpio/consumer.h>
+#include <linux/gpio/driver.h>
#include <linux/i2c.h>
#include <linux/iopoll.h>
#include <linux/module.h>
@@ -54,6 +56,14 @@
#define BPP_18_RGB BIT(0)
#define SN_HPD_DISABLE_REG 0x5C
#define HPD_DISABLE BIT(0)
+#define SN_GPIO_IO_REG 0x5E
+#define SN_GPIO_INPUT_SHIFT 4
+#define SN_GPIO_OUTPUT_SHIFT 0
+#define SN_GPIO_CTRL_REG 0x5F
+#define SN_GPIO_MUX_INPUT 0
+#define SN_GPIO_MUX_OUTPUT 1
+#define SN_GPIO_MUX_SPECIAL 2
+#define SN_GPIO_MUX_MASK 0x3
#define SN_AUX_WDATA_REG(x) (0x64 + (x))
#define SN_AUX_ADDR_19_16_REG 0x74
#define SN_AUX_ADDR_15_8_REG 0x75
@@ -88,6 +98,35 @@
#define SN_REGULATOR_SUPPLY_NUM 4
+#define SN_NUM_GPIOS 4
+#define SN_GPIO_PHYSICAL_OFFSET 1
+
+/**
+ * struct ti_sn_bridge - Platform data for ti-sn65dsi86 driver.
+ * @dev: Pointer to our device.
+ * @regmap: Regmap for accessing i2c.
+ * @aux: Our aux channel.
+ * @bridge: Our bridge.
+ * @connector: Our connector.
+ * @debugfs: Used for managing our debugfs.
+ * @host_node: Remote DSI node.
+ * @dsi: Our MIPI DSI source.
+ * @refclk: Our reference clock.
+ * @panel: Our panel.
+ * @enable_gpio: The GPIO we toggle to enable the bridge.
+ * @supplies: Data for bulk enabling/disabling our regulators.
+ * @dp_lanes: Count of dp_lanes we're using.
+ *
+ * @gchip: If we expose our GPIOs, this is used.
+ * @gchip_output: A cache of whether we've set GPIOs to output. This
+ * serves double-duty of keeping track of the direction and
+ * also keeping track of whether we've incremented the
+ * pm_runtime reference count for this pin, which we do
+ * whenever a pin is configured as an output. This is a
+ * bitmap so we can do atomic ops on it without an extra
+ * lock so concurrent users of our 4 GPIOs don't stomp on
+ * each other's read-modify-write.
+ */
struct ti_sn_bridge {
struct device *dev;
struct regmap *regmap;
@@ -102,6 +141,9 @@ struct ti_sn_bridge {
struct gpio_desc *enable_gpio;
struct regulator_bulk_data supplies[SN_REGULATOR_SUPPLY_NUM];
int dp_lanes;
+
+ struct gpio_chip gchip;
+ DECLARE_BITMAP(gchip_output, SN_NUM_GPIOS);
};
static const struct regmap_range ti_sn_bridge_volatile_ranges[] = {
@@ -874,6 +916,173 @@ static int ti_sn_bridge_parse_dsi_host(struct ti_sn_bridge *pdata)
return 0;
}
+static int tn_sn_bridge_of_xlate(struct gpio_chip *chip,
+ const struct of_phandle_args *gpiospec,
+ u32 *flags)
+{
+ if (WARN_ON(gpiospec->args_count < chip->of_gpio_n_cells))
+ return -EINVAL;
+
+ if (gpiospec->args[0] > chip->ngpio || gpiospec->args[0] < 1)
+ return -EINVAL;
+
+ if (flags)
+ *flags = gpiospec->args[1];
+
+ return gpiospec->args[0] - SN_GPIO_PHYSICAL_OFFSET;
+}
+
+static int ti_sn_bridge_gpio_get_direction(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ struct ti_sn_bridge *pdata = gpiochip_get_data(chip);
+
+ /*
+ * We already have to keep track of the direction because we use
+ * that to figure out whether we've powered the device. We can
+ * just return that rather than (maybe) powering up the device
+ * to ask its direction.
+ */
+ return test_bit(offset, pdata->gchip_output) ?
+ GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
+}
+
+static int ti_sn_bridge_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+ struct ti_sn_bridge *pdata = gpiochip_get_data(chip);
+ unsigned int val;
+ int ret;
+
+ /*
+ * When the pin is an input we don't forcibly keep the bridge
+ * powered--we just power it on to read the pin. NOTE: part of
+ * the reason this works is that the bridge defaults (when
+ * powered back on) to all 4 GPIOs being configured as GPIO input.
+ * Also note that if something else is keeping the chip powered the
+ * pm_runtime functions are lightweight increments of a refcount.
+ */
+ pm_runtime_get_sync(pdata->dev);
+ ret = regmap_read(pdata->regmap, SN_GPIO_IO_REG, &val);
+ pm_runtime_put(pdata->dev);
+
+ if (ret)
+ return ret;
+
+ return !!(val & BIT(SN_GPIO_INPUT_SHIFT + offset));
+}
+
+static void ti_sn_bridge_gpio_set(struct gpio_chip *chip, unsigned int offset,
+ int val)
+{
+ struct ti_sn_bridge *pdata = gpiochip_get_data(chip);
+ int ret;
+
+ if (!test_bit(offset, pdata->gchip_output)) {
+ dev_err(pdata->dev, "Ignoring GPIO set while input\n");
+ return;
+ }
+
+ val &= 1;
+ ret = regmap_update_bits(pdata->regmap, SN_GPIO_IO_REG,
+ BIT(SN_GPIO_OUTPUT_SHIFT + offset),
+ val << (SN_GPIO_OUTPUT_SHIFT + offset));
+}
+
+static int ti_sn_bridge_gpio_direction_input(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ struct ti_sn_bridge *pdata = gpiochip_get_data(chip);
+ int shift = offset * 2;
+ int ret;
+
+ if (!test_and_clear_bit(offset, pdata->gchip_output))
+ return 0;
+
+ ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
+ SN_GPIO_MUX_MASK << shift,
+ SN_GPIO_MUX_INPUT << shift);
+ if (ret) {
+ set_bit(offset, pdata->gchip_output);
+ return ret;
+ }
+
+ /*
+ * NOTE: if nobody else is powering the device this may fully power
+ * it off and when it comes back it will have lost all state, but
+ * that's OK because the default is input and we're now an input.
+ */
+ pm_runtime_put(pdata->dev);
+
+ return 0;
+}
+
+static int ti_sn_bridge_gpio_direction_output(struct gpio_chip *chip,
+ unsigned int offset, int val)
+{
+ struct ti_sn_bridge *pdata = gpiochip_get_data(chip);
+ int shift = offset * 2;
+ int ret;
+
+ if (test_and_set_bit(offset, pdata->gchip_output))
+ return 0;
+
+ pm_runtime_get_sync(pdata->dev);
+
+ /* Set value first to avoid glitching */
+ ti_sn_bridge_gpio_set(chip, offset, val);
+
+ /* Set direction */
+ ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
+ SN_GPIO_MUX_MASK << shift,
+ SN_GPIO_MUX_OUTPUT << shift);
+ if (ret) {
+ clear_bit(offset, pdata->gchip_output);
+ pm_runtime_put(pdata->dev);
+ }
+
+ return ret;
+}
+
+static void ti_sn_bridge_gpio_free(struct gpio_chip *chip, unsigned int offset)
+{
+ /* We won't keep pm_runtime if we're input, so switch there on free */
+ ti_sn_bridge_gpio_direction_input(chip, offset);
+}
+
+static const char * const ti_sn_bridge_gpio_names[SN_NUM_GPIOS] = {
+ "GPIO1", "GPIO2", "GPIO3", "GPIO4"
+};
+
+static int ti_sn_setup_gpio_controller(struct ti_sn_bridge *pdata)
+{
+ int ret;
+
+ /* Only init if someone is going to use us as a GPIO controller */
+ if (!of_property_read_bool(pdata->dev->of_node, "gpio-controller"))
+ return 0;
+
+ pdata->gchip.label = dev_name(pdata->dev);
+ pdata->gchip.parent = pdata->dev;
+ pdata->gchip.owner = THIS_MODULE;
+ pdata->gchip.of_xlate = tn_sn_bridge_of_xlate;
+ pdata->gchip.of_gpio_n_cells = 2;
+ pdata->gchip.free = ti_sn_bridge_gpio_free;
+ pdata->gchip.get_direction = ti_sn_bridge_gpio_get_direction;
+ pdata->gchip.direction_input = ti_sn_bridge_gpio_direction_input;
+ pdata->gchip.direction_output = ti_sn_bridge_gpio_direction_output;
+ pdata->gchip.get = ti_sn_bridge_gpio_get;
+ pdata->gchip.set = ti_sn_bridge_gpio_set;
+ pdata->gchip.can_sleep = true;
+ pdata->gchip.names = ti_sn_bridge_gpio_names;
+ pdata->gchip.ngpio = SN_NUM_GPIOS;
+ pdata->gchip.base = -1;
+ ret = devm_gpiochip_add_data(pdata->dev, &pdata->gchip, pdata);
+ if (ret)
+ dev_err(pdata->dev, "can't add gpio chip\n");
+
+ return ret;
+}
+
static int ti_sn_bridge_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -937,6 +1146,12 @@ static int ti_sn_bridge_probe(struct i2c_client *client,
pm_runtime_enable(pdata->dev);
+ ret = ti_sn_setup_gpio_controller(pdata);
+ if (ret) {
+ pm_runtime_disable(pdata->dev);
+ return ret;
+ }
+
i2c_set_clientdata(client, pdata);
pdata->aux.name = "ti-sn65dsi86-aux";