diff --git a/drivers/gpu/drm/bridge/sii902x.c b/drivers/gpu/drm/bridge/sii902x.c index e59a13542333..bfa902013aa4 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 * @@ -21,6 +23,7 @@ */ #include +#include #include #include #include @@ -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; + int num = 0, 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)); - - 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;