diff options
| -rw-r--r-- | drivers/gpu/drm/bridge/ti-sn65dsi86.c | 129 |
1 files changed, 94 insertions, 35 deletions
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 5c2a91a4c293..db027528febd 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -132,6 +132,8 @@ * @dp_lanes: Count of dp_lanes we're using. * @ln_assign: Value to program to the LN_ASSIGN register. * @ln_polrs: Value for the 4-bit LN_POLRS field of SN_ENH_FRAME_REG. + * @comms_enabled: If true then communication over the aux channel is enabled. + * @comms_mutex: Protects modification of comms_enabled. * * @gchip: If we expose our GPIOs, this is used. * @gchip_output: A cache of whether we've set GPIOs to output. This @@ -162,6 +164,8 @@ struct ti_sn65dsi86 { int dp_lanes; u8 ln_assign; u8 ln_polrs; + bool comms_enabled; + struct mutex comms_mutex; #if defined(CONFIG_OF_GPIO) struct gpio_chip gchip; @@ -250,6 +254,47 @@ static void ti_sn_bridge_set_refclk_freq(struct ti_sn65dsi86 *pdata) REFCLK_FREQ(i)); } +static void ti_sn65dsi86_enable_comms(struct ti_sn65dsi86 *pdata) +{ + mutex_lock(&pdata->comms_mutex); + + /* configure bridge ref_clk */ + ti_sn_bridge_set_refclk_freq(pdata); + + /* + * HPD on this bridge chip is a bit useless. This is an eDP bridge + * so the HPD is an internal signal that's only there to signal that + * the panel is done powering up. ...but the bridge chip debounces + * this signal by between 100 ms and 400 ms (depending on process, + * voltage, and temperate--I measured it at about 200 ms). One + * particular panel asserted HPD 84 ms after it was powered on meaning + * that we saw HPD 284 ms after power on. ...but the same panel said + * that instead of looking at HPD you could just hardcode a delay of + * 200 ms. We'll assume that the panel driver will have the hardcoded + * delay in its prepare and always disable HPD. + * + * If HPD somehow makes sense on some future panel we'll have to + * change this to be conditional on someone specifying that HPD should + * be used. + */ + regmap_update_bits(pdata->regmap, SN_HPD_DISABLE_REG, HPD_DISABLE, + HPD_DISABLE); + + pdata->comms_enabled = true; + + mutex_unlock(&pdata->comms_mutex); +} + +static void ti_sn65dsi86_disable_comms(struct ti_sn65dsi86 *pdata) +{ + mutex_lock(&pdata->comms_mutex); + + pdata->comms_enabled = false; + clk_disable_unprepare(pdata->refclk); + + mutex_unlock(&pdata->comms_mutex); +} + static int __maybe_unused ti_sn65dsi86_resume(struct device *dev) { struct ti_sn65dsi86 *pdata = dev_get_drvdata(dev); @@ -263,6 +308,16 @@ static int __maybe_unused ti_sn65dsi86_resume(struct device *dev) gpiod_set_value(pdata->enable_gpio, 1); + /* + * If we have a reference clock we can enable communication w/ the + * panel (including the aux channel) w/out any need for an input clock + * so we can do it in resume which lets us read the EDID before + * pre_enable(). Without a reference clock we need the MIPI reference + * clock so reading early doesn't work. + */ + if (pdata->refclk) + ti_sn65dsi86_enable_comms(pdata); + return ret; } @@ -271,6 +326,9 @@ static int __maybe_unused ti_sn65dsi86_suspend(struct device *dev) struct ti_sn65dsi86 *pdata = dev_get_drvdata(dev); int ret; + if (pdata->refclk) + ti_sn65dsi86_disable_comms(pdata); + gpiod_set_value(pdata->enable_gpio, 0); ret = regulator_bulk_disable(SN_REGULATOR_SUPPLY_NUM, pdata->supplies); @@ -845,27 +903,8 @@ static void ti_sn_bridge_pre_enable(struct drm_bridge *bridge) pm_runtime_get_sync(pdata->dev); - /* configure bridge ref_clk */ - ti_sn_bridge_set_refclk_freq(pdata); - - /* - * HPD on this bridge chip is a bit useless. This is an eDP bridge - * so the HPD is an internal signal that's only there to signal that - * the panel is done powering up. ...but the bridge chip debounces - * this signal by between 100 ms and 400 ms (depending on process, - * voltage, and temperate--I measured it at about 200 ms). One - * particular panel asserted HPD 84 ms after it was powered on meaning - * that we saw HPD 284 ms after power on. ...but the same panel said - * that instead of looking at HPD you could just hardcode a delay of - * 200 ms. We'll assume that the panel driver will have the hardcoded - * delay in its prepare and always disable HPD. - * - * If HPD somehow makes sense on some future panel we'll have to - * change this to be conditional on someone specifying that HPD should - * be used. - */ - regmap_update_bits(pdata->regmap, SN_HPD_DISABLE_REG, HPD_DISABLE, - HPD_DISABLE); + if (!pdata->refclk) + ti_sn65dsi86_enable_comms(pdata); drm_panel_prepare(pdata->panel); } @@ -876,7 +915,8 @@ static void ti_sn_bridge_post_disable(struct drm_bridge *bridge) drm_panel_unprepare(pdata->panel); - clk_disable_unprepare(pdata->refclk); + if (!pdata->refclk) + ti_sn65dsi86_disable_comms(pdata); pm_runtime_put_sync(pdata->dev); } @@ -910,6 +950,20 @@ static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux, if (len > SN_AUX_MAX_PAYLOAD_BYTES) return -EINVAL; + pm_runtime_get_sync(pdata->dev); + mutex_lock(&pdata->comms_mutex); + + /* + * If someone tries to do a DDC over AUX transaction before pre_enable() + * on a device without a dedicated reference clock then we just can't + * do it. Fail right away. This prevents non-refclk users from reading + * the EDID before enabling the panel but such is life. + */ + if (!pdata->comms_enabled) { + ret = -EIO; + goto exit; + } + switch (request) { case DP_AUX_NATIVE_WRITE: case DP_AUX_I2C_WRITE: @@ -920,7 +974,8 @@ static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux, msg->reply = 0; break; default: - return -EINVAL; + ret = -EINVAL; + goto exit; } BUILD_BUG_ON(sizeof(addr_len) != sizeof(__be32)); @@ -944,11 +999,11 @@ static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux, ret = regmap_read_poll_timeout(pdata->regmap, SN_AUX_CMD_REG, val, !(val & AUX_CMD_SEND), 0, 50 * 1000); if (ret) - return ret; + goto exit; ret = regmap_read(pdata->regmap, SN_AUX_CMD_STATUS_REG, &val); if (ret) - return ret; + goto exit; if (val & AUX_IRQ_STATUS_AUX_RPLY_TOUT) { /* @@ -956,13 +1011,14 @@ static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux, * but it hit a timeout. We ignore defers here because they're * handled in hardware. */ - return -ETIMEDOUT; + ret = -ETIMEDOUT; + goto exit; } if (val & AUX_IRQ_STATUS_AUX_SHORT) { ret = regmap_read(pdata->regmap, SN_AUX_LENGTH_REG, &len); if (ret) - return ret; + goto exit; } else if (val & AUX_IRQ_STATUS_NAT_I2C_FAIL) { switch (request) { case DP_AUX_I2C_WRITE: @@ -974,18 +1030,19 @@ static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux, msg->reply |= DP_AUX_NATIVE_REPLY_NACK; break; } - return 0; + len = 0; + goto exit; } - if (request == DP_AUX_NATIVE_WRITE || request == DP_AUX_I2C_WRITE || - len == 0) - return len; + if (request != DP_AUX_NATIVE_WRITE && request != DP_AUX_I2C_WRITE && len != 0) + ret = regmap_bulk_read(pdata->regmap, SN_AUX_RDATA_REG(0), buf, len); - ret = regmap_bulk_read(pdata->regmap, SN_AUX_RDATA_REG(0), buf, len); - if (ret) - return ret; +exit: + mutex_unlock(&pdata->comms_mutex); + pm_runtime_mark_last_busy(pdata->dev); + pm_runtime_put_autosuspend(pdata->dev); - return len; + return ret ? ret : len; } static int ti_sn_bridge_parse_dsi_host(struct ti_sn65dsi86 *pdata) @@ -1391,6 +1448,8 @@ static int ti_sn65dsi86_probe(struct i2c_client *client, dev_set_drvdata(dev, pdata); pdata->dev = dev; + mutex_init(&pdata->comms_mutex); + pdata->regmap = devm_regmap_init_i2c(client, &ti_sn65dsi86_regmap_config); if (IS_ERR(pdata->regmap)) { |