drm/bridge: tc358767: add IRQ and HPD support

Add support for interrupt and hotplug handling. Both are optional.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528082747.3631-24-tomi.valkeinen@ti.com

diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
index b820a59..72666e0 100644 (file)
--- a/drivers/gpu/drm/bridge/tc358767.c
+++ b/drivers/gpu/drm/bridge/tc358767.c
@@ -71,6 +71,7 @@
 
 /* System */
 #define TC_IDREG               0x0500
+#define SYSSTAT                        0x0508
 #define SYSCTRL                        0x0510
 #define DP0_AUDSRC_NO_INPUT            (0 << 3)
 #define DP0_AUDSRC_I2S_RX              (1 << 3)
@@ -79,9 +80,16 @@
 #define DP0_VIDSRC_DPI_RX              (2 << 0)
 #define DP0_VIDSRC_COLOR_BAR           (3 << 0)
 #define GPIOM                  0x0540
+#define GPIOC                  0x0544
+#define GPIOO                  0x0548
 #define GPIOI                  0x054c
 #define INTCTL_G               0x0560
 #define INTSTS_G               0x0564
+
+#define INT_SYSERR             BIT(16)
+#define INT_GPIO_H(x)          (1 << (x == 0 ? 2 : 10))
+#define INT_GPIO_LC(x)         (1 << (x == 0 ? 3 : 11))
+
 #define INT_GP0_LCNT           0x0584
 #define INT_GP1_LCNT           0x0588
 
@@ -219,6 +227,12 @@ struct tc_data {
        struct gpio_desc        *sd_gpio;
        struct gpio_desc        *reset_gpio;
        struct clk              *refclk;
+
+       /* do we have IRQ */
+       bool                    have_irq;
+
+       /* HPD pin number (0 or 1) or -ENODEV */
+       int                     hpd_pin;
 };
 
 static inline struct tc_data *aux_to_tc(struct drm_dp_aux *a)
@@ -1109,6 +1123,12 @@ static void tc_bridge_enable(struct drm_bridge *bridge)
        struct tc_data *tc = bridge_to_tc(bridge);
        int ret;
 
+       ret = tc_get_display_props(tc);
+       if (ret < 0) {
+               dev_err(tc->dev, "failed to read display props: %d\n", ret);
+               return;
+       }
+
        ret = tc_main_link_enable(tc);
        if (ret < 0) {
                dev_err(tc->dev, "main link enable error: %d\n", ret);
@@ -1221,19 +1241,40 @@ static int tc_connector_get_modes(struct drm_connector *connector)
        return count;
 }
 
-static void tc_connector_set_polling(struct tc_data *tc,
-                                    struct drm_connector *connector)
-{
-       /* TODO: add support for HPD */
-       connector->polled = DRM_CONNECTOR_POLL_CONNECT |
-                           DRM_CONNECTOR_POLL_DISCONNECT;
-}
-
 static const struct drm_connector_helper_funcs tc_connector_helper_funcs = {
        .get_modes = tc_connector_get_modes,
 };
 
+static enum drm_connector_status tc_connector_detect(struct drm_connector *connector,
+                                                    bool force)
+{
+       struct tc_data *tc = connector_to_tc(connector);
+       bool conn;
+       u32 val;
+       int ret;
+
+       if (tc->hpd_pin < 0) {
+               if (tc->panel)
+                       return connector_status_connected;
+               else
+                       return connector_status_unknown;
+       }
+
+       tc_read(GPIOI, &val);
+
+       conn = val & BIT(tc->hpd_pin);
+
+       if (conn)
+               return connector_status_connected;
+       else
+               return connector_status_disconnected;
+
+err:
+       return connector_status_unknown;
+}
+
 static const struct drm_connector_funcs tc_connector_funcs = {
+       .detect = tc_connector_detect,
        .fill_modes = drm_helper_probe_single_connector_modes,
        .destroy = drm_connector_cleanup,
        .reset = drm_atomic_helper_connector_reset,
@@ -1248,7 +1289,7 @@ static int tc_bridge_attach(struct drm_bridge *bridge)
        struct drm_device *drm = bridge->dev;
        int ret;
 
-       /* Create eDP connector */
+       /* Create DP/eDP connector */
        drm_connector_helper_add(&tc->connector, &tc_connector_helper_funcs);
        ret = drm_connector_init(drm, &tc->connector, &tc_connector_funcs,
                                 tc->panel ? DRM_MODE_CONNECTOR_eDP :
@@ -1256,6 +1297,15 @@ static int tc_bridge_attach(struct drm_bridge *bridge)
        if (ret)
                return ret;
 
+       /* Don't poll if don't have HPD connected */
+       if (tc->hpd_pin >= 0) {
+               if (tc->have_irq)
+                       tc->connector.polled = DRM_CONNECTOR_POLL_HPD;
+               else
+                       tc->connector.polled = DRM_CONNECTOR_POLL_CONNECT |
+                                              DRM_CONNECTOR_POLL_DISCONNECT;
+       }
+
        if (tc->panel)
                drm_panel_attach(tc->panel, &tc->connector);
 
@@ -1322,6 +1372,49 @@ static const struct regmap_config tc_regmap_config = {
        .val_format_endian = REGMAP_ENDIAN_LITTLE,
 };
 
+static irqreturn_t tc_irq_handler(int irq, void *arg)
+{
+       struct tc_data *tc = arg;
+       u32 val;
+       int r;
+
+       r = regmap_read(tc->regmap, INTSTS_G, &val);
+       if (r)
+               return IRQ_NONE;
+
+       if (!val)
+               return IRQ_NONE;
+
+       if (val & INT_SYSERR) {
+               u32 stat = 0;
+
+               regmap_read(tc->regmap, SYSSTAT, &stat);
+
+               dev_err(tc->dev, "syserr %x\n", stat);
+       }
+
+       if (tc->hpd_pin >= 0 && tc->bridge.dev) {
+               /*
+                * H is triggered when the GPIO goes high.
+                *
+                * LC is triggered when the GPIO goes low and stays low for
+                * the duration of LCNT
+                */
+               bool h = val & INT_GPIO_H(tc->hpd_pin);
+               bool lc = val & INT_GPIO_LC(tc->hpd_pin);
+
+               dev_dbg(tc->dev, "GPIO%d: %s %s\n", tc->hpd_pin,
+                       h ? "H" : "", lc ? "LC" : "");
+
+               if (h || lc)
+                       drm_kms_helper_hotplug_event(tc->bridge.dev);
+       }
+
+       regmap_write(tc->regmap, INTSTS_G, val);
+
+       return IRQ_HANDLED;
+}
+
 static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id)
 {
        struct device *dev = &client->dev;
@@ -1373,6 +1466,33 @@ static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id)
                return ret;
        }
 
+       ret = of_property_read_u32(dev->of_node, "toshiba,hpd-pin",
+                                  &tc->hpd_pin);
+       if (ret) {
+               tc->hpd_pin = -ENODEV;
+       } else {
+               if (tc->hpd_pin < 0 || tc->hpd_pin > 1) {
+                       dev_err(dev, "failed to parse HPD number\n");
+                       return ret;
+               }
+       }
+
+       if (client->irq > 0) {
+               /* enable SysErr */
+               regmap_write(tc->regmap, INTCTL_G, INT_SYSERR);
+
+               ret = devm_request_threaded_irq(dev, client->irq,
+                                               NULL, tc_irq_handler,
+                                               IRQF_ONESHOT,
+                                               "tc358767-irq", tc);
+               if (ret) {
+                       dev_err(dev, "failed to register dp interrupt\n");
+                       return ret;
+               }
+
+               tc->have_irq = true;
+       }
+
        ret = regmap_read(tc->regmap, TC_IDREG, &tc->rev);
        if (ret) {
                dev_err(tc->dev, "can not read device ID: %d\n", ret);
@@ -1386,6 +1506,22 @@ static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id)
 
        tc->assr = (tc->rev == 0x6601); /* Enable ASSR for eDP panels */
 
+       if (tc->hpd_pin >= 0) {
+               u32 lcnt_reg = tc->hpd_pin == 0 ? INT_GP0_LCNT : INT_GP1_LCNT;
+               u32 h_lc = INT_GPIO_H(tc->hpd_pin) | INT_GPIO_LC(tc->hpd_pin);
+
+               /* Set LCNT to 2ms */
+               regmap_write(tc->regmap, lcnt_reg,
+                            clk_get_rate(tc->refclk) * 2 / 1000);
+               /* We need the "alternate" mode for HPD */
+               regmap_write(tc->regmap, GPIOM, BIT(tc->hpd_pin));
+
+               if (tc->have_irq) {
+                       /* enable H & LC */
+                       regmap_update_bits(tc->regmap, INTCTL_G, h_lc, h_lc);
+               }
+       }
+
        ret = tc_aux_link_setup(tc);
        if (ret)
                return ret;
@@ -1398,12 +1534,6 @@ static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id)
        if (ret)
                return ret;
 
-       ret = tc_get_display_props(tc);
-       if (ret)
-               goto err_unregister_aux;
-
-       tc_connector_set_polling(tc, &tc->connector);
-
        tc->bridge.funcs = &tc_bridge_funcs;
        tc->bridge.of_node = dev->of_node;
        drm_bridge_add(&tc->bridge);
@@ -1411,9 +1541,6 @@ static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id)
        i2c_set_clientdata(client, tc);
 
        return 0;
-err_unregister_aux:
-       drm_dp_aux_unregister(&tc->aux);
-       return ret;
 }
 
 static int tc_remove(struct i2c_client *client)