diff --git a/drivers/gpu/drm/bridge/sii902x.c b/drivers/gpu/drm/bridge/sii902x.c
index e59a135423336bd187f0038956f06ac4574d94dc..bfa902013aa42e06f3eff686d25ba593cd9b2b89 100644
--- a/drivers/gpu/drm/bridge/sii902x.c
+++ b/drivers/gpu/drm/bridge/sii902x.c
@@ -1,4 +1,6 @@
/*
+ * Copyright (C) 2018 Renesas Electronics
+ *
* Copyright (C) 2016 Atmel
* Bo Shen <voice.shen@atmel.com>
*
@@ -21,6 +23,7 @@
*/
#include <linux/gpio/consumer.h>
+#include <linux/i2c-mux.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/regmap.h>
@@ -86,8 +89,49 @@ struct sii902x {
struct drm_bridge bridge;
struct drm_connector connector;
struct gpio_desc *reset_gpio;
+ struct i2c_mux_core *i2cmux;
};
+static int sii902x_read_unlocked(struct i2c_client *i2c, u8 reg, u8 *val)
+{
+ union i2c_smbus_data data;
+ int ret;
+
+ ret = __i2c_smbus_xfer(i2c->adapter, i2c->addr, i2c->flags,
+ I2C_SMBUS_READ, reg, I2C_SMBUS_BYTE_DATA, &data);
+
+ if (ret < 0)
+ return ret;
+
+ *val = data.byte;
+ return 0;
+}
+
+static int sii902x_write_unlocked(struct i2c_client *i2c, u8 reg, u8 val)
+{
+ union i2c_smbus_data data;
+
+ data.byte = val;
+
+ return __i2c_smbus_xfer(i2c->adapter, i2c->addr, i2c->flags,
+ I2C_SMBUS_WRITE, reg, I2C_SMBUS_BYTE_DATA,
+ &data);
+}
+
+static int sii902x_update_bits_unlocked(struct i2c_client *i2c, u8 reg, u8 mask,
+ u8 val)
+{
+ int ret;
+ u8 status;
+
+ ret = sii902x_read_unlocked(i2c, reg, &status);
+ if (ret)
+ return ret;
+ status &= ~mask;
+ status |= val & mask;
+ return sii902x_write_unlocked(i2c, reg, status);
+}
+
static inline struct sii902x *bridge_to_sii902x(struct drm_bridge *bridge)
{
return container_of(bridge, struct sii902x, bridge);
@@ -135,41 +179,11 @@ static const struct drm_connector_funcs sii902x_connector_funcs = {
static int sii902x_get_modes(struct drm_connector *connector)
{
struct sii902x *sii902x = connector_to_sii902x(connector);
- struct regmap *regmap = sii902x->regmap;
u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
- struct device *dev = &sii902x->i2c->dev;
- unsigned long timeout;
- unsigned int retries;
- unsigned int status;
struct edid *edid;
- int num = 0;
- int ret;
-
- ret = regmap_update_bits(regmap, SII902X_SYS_CTRL_DATA,
- SII902X_SYS_CTRL_DDC_BUS_REQ,
- SII902X_SYS_CTRL_DDC_BUS_REQ);
- if (ret)
- return ret;
-
- timeout = jiffies +
- msecs_to_jiffies(SII902X_I2C_BUS_ACQUISITION_TIMEOUT_MS);
- do {
- ret = regmap_read(regmap, SII902X_SYS_CTRL_DATA, &status);
- if (ret)
- return ret;
- } while (!(status & SII902X_SYS_CTRL_DDC_BUS_GRTD) &&
- time_before(jiffies, timeout));
+ int num = 0, ret;
- if (!(status & SII902X_SYS_CTRL_DDC_BUS_GRTD)) {
- dev_err(dev, "failed to acquire the i2c bus\n");
- return -ETIMEDOUT;
- }
-
- ret = regmap_write(regmap, SII902X_SYS_CTRL_DATA, status);
- if (ret)
- return ret;
-
- edid = drm_get_edid(connector, sii902x->i2c->adapter);
+ edid = drm_get_edid(connector, sii902x->i2cmux->adapter[0]);
drm_connector_update_edid_property(connector, edid);
if (edid) {
num = drm_add_edid_modes(connector, edid);
@@ -181,42 +195,6 @@ static int sii902x_get_modes(struct drm_connector *connector)
if (ret)
return ret;
- /*
- * Sometimes the I2C bus can stall after failure to use the
- * EDID channel. Retry a few times to see if things clear
- * up, else continue anyway.
- */
- retries = 5;
- do {
- ret = regmap_read(regmap, SII902X_SYS_CTRL_DATA,
- &status);
- retries--;
- } while (ret && retries);
- if (ret)
- dev_err(dev, "failed to read status (%d)\n", ret);
-
- ret = regmap_update_bits(regmap, SII902X_SYS_CTRL_DATA,
- SII902X_SYS_CTRL_DDC_BUS_REQ |
- SII902X_SYS_CTRL_DDC_BUS_GRTD, 0);
- if (ret)
- return ret;
-
- timeout = jiffies +
- msecs_to_jiffies(SII902X_I2C_BUS_ACQUISITION_TIMEOUT_MS);
- do {
- ret = regmap_read(regmap, SII902X_SYS_CTRL_DATA, &status);
- if (ret)
- return ret;
- } while (status & (SII902X_SYS_CTRL_DDC_BUS_REQ |
- SII902X_SYS_CTRL_DDC_BUS_GRTD) &&
- time_before(jiffies, timeout));
-
- if (status & (SII902X_SYS_CTRL_DDC_BUS_REQ |
- SII902X_SYS_CTRL_DDC_BUS_GRTD)) {
- dev_err(dev, "failed to release the i2c bus\n");
- return -ETIMEDOUT;
- }
-
return num;
}
@@ -366,6 +344,121 @@ static irqreturn_t sii902x_interrupt(int irq, void *data)
return IRQ_HANDLED;
}
+/*
+ * The purpose of sii902x_i2c_bypass_select is to enable the pass through
+ * mode of the HDMI transmitter. Do not use regmap from within this function,
+ * only use sii902x_*_unlocked functions to read/modify/write registers.
+ * We are holding the parent adapter lock here, keep this in mind before
+ * adding more i2c transactions.
+ *
+ * Also, since SII902X_SYS_CTRL_DATA is used with regmap_update_bits elsewhere
+ * in this driver, we need to make sure that we only touch 0x1A[2:1] from
+ * within sii902x_i2c_bypass_select and sii902x_i2c_bypass_deselect, and that
+ * we leave the remaining bits as we have found them.
+ */
+static int sii902x_i2c_bypass_select(struct i2c_mux_core *mux, u32 chan_id)
+{
+ struct sii902x *sii902x = i2c_mux_priv(mux);
+ struct device *dev = &sii902x->i2c->dev;
+ unsigned long timeout;
+ u8 status;
+ int ret;
+
+ ret = sii902x_update_bits_unlocked(sii902x->i2c, SII902X_SYS_CTRL_DATA,
+ SII902X_SYS_CTRL_DDC_BUS_REQ,
+ SII902X_SYS_CTRL_DDC_BUS_REQ);
+ if (ret)
+ return ret;
+
+ timeout = jiffies +
+ msecs_to_jiffies(SII902X_I2C_BUS_ACQUISITION_TIMEOUT_MS);
+ do {
+ ret = sii902x_read_unlocked(sii902x->i2c, SII902X_SYS_CTRL_DATA,
+ &status);
+ if (ret)
+ return ret;
+ } while (!(status & SII902X_SYS_CTRL_DDC_BUS_GRTD) &&
+ time_before(jiffies, timeout));
+
+ if (!(status & SII902X_SYS_CTRL_DDC_BUS_GRTD)) {
+ dev_err(dev, "Failed to acquire the i2c bus\n");
+ return -ETIMEDOUT;
+ }
+
+ return sii902x_write_unlocked(sii902x->i2c, SII902X_SYS_CTRL_DATA,
+ status);
+}
+
+/*
+ * The purpose of sii902x_i2c_bypass_deselect is to disable the pass through
+ * mode of the HDMI transmitter. Do not use regmap from within this function,
+ * only use sii902x_*_unlocked functions to read/modify/write registers.
+ * We are holding the parent adapter lock here, keep this in mind before
+ * adding more i2c transactions.
+ *
+ * Also, since SII902X_SYS_CTRL_DATA is used with regmap_update_bits elsewhere
+ * in this driver, we need to make sure that we only touch 0x1A[2:1] from
+ * within sii902x_i2c_bypass_select and sii902x_i2c_bypass_deselect, and that
+ * we leave the remaining bits as we have found them.
+ */
+static int sii902x_i2c_bypass_deselect(struct i2c_mux_core *mux, u32 chan_id)
+{
+ struct sii902x *sii902x = i2c_mux_priv(mux);
+ struct device *dev = &sii902x->i2c->dev;
+ unsigned long timeout;
+ unsigned int retries;
+ u8 status;
+ int ret;
+
+ /*
+ * When the HDMI transmitter is in pass through mode, we need an
+ * (undocumented) additional delay between STOP and START conditions
+ * to guarantee the bus won't get stuck.
+ */
+ udelay(30);
+
+ /*
+ * Sometimes the I2C bus can stall after failure to use the
+ * EDID channel. Retry a few times to see if things clear
+ * up, else continue anyway.
+ */
+ retries = 5;
+ do {
+ ret = sii902x_read_unlocked(sii902x->i2c, SII902X_SYS_CTRL_DATA,
+ &status);
+ retries--;
+ } while (ret && retries);
+ if (ret) {
+ dev_err(dev, "failed to read status (%d)\n", ret);
+ return ret;
+ }
+
+ ret = sii902x_update_bits_unlocked(sii902x->i2c, SII902X_SYS_CTRL_DATA,
+ SII902X_SYS_CTRL_DDC_BUS_REQ |
+ SII902X_SYS_CTRL_DDC_BUS_GRTD, 0);
+ if (ret)
+ return ret;
+
+ timeout = jiffies +
+ msecs_to_jiffies(SII902X_I2C_BUS_ACQUISITION_TIMEOUT_MS);
+ do {
+ ret = sii902x_read_unlocked(sii902x->i2c, SII902X_SYS_CTRL_DATA,
+ &status);
+ if (ret)
+ return ret;
+ } while (status & (SII902X_SYS_CTRL_DDC_BUS_REQ |
+ SII902X_SYS_CTRL_DDC_BUS_GRTD) &&
+ time_before(jiffies, timeout));
+
+ if (status & (SII902X_SYS_CTRL_DDC_BUS_REQ |
+ SII902X_SYS_CTRL_DDC_BUS_GRTD)) {
+ dev_err(dev, "failed to release the i2c bus\n");
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+
static int sii902x_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -375,6 +468,13 @@ static int sii902x_probe(struct i2c_client *client,
u8 chipid[4];
int ret;
+ ret = i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_BYTE_DATA);
+ if (!ret) {
+ dev_err(dev, "I2C adapter not suitable\n");
+ return -EIO;
+ }
+
sii902x = devm_kzalloc(dev, sizeof(*sii902x), GFP_KERNEL);
if (!sii902x)
return -ENOMEM;
@@ -433,7 +533,15 @@ static int sii902x_probe(struct i2c_client *client,
i2c_set_clientdata(client, sii902x);
- return 0;
+ sii902x->i2cmux = i2c_mux_alloc(client->adapter, dev,
+ 1, 0, I2C_MUX_GATE,
+ sii902x_i2c_bypass_select,
+ sii902x_i2c_bypass_deselect);
+ if (!sii902x->i2cmux)
+ return -ENOMEM;
+
+ sii902x->i2cmux->priv = sii902x;
+ return i2c_mux_add_adapter(sii902x->i2cmux, 0, 0, 0);
}
static int sii902x_remove(struct i2c_client *client)
@@ -441,6 +549,7 @@ static int sii902x_remove(struct i2c_client *client)
{
struct sii902x *sii902x = i2c_get_clientdata(client);
+ i2c_mux_del_adapters(sii902x->i2cmux);
drm_bridge_remove(&sii902x->bridge);
return 0;