From: Sean Paul Date: Mon, 13 Aug 2018 21:30:42 +0000 (-0400) Subject: drm/bridge: ti-sn65dsi86: Implement AUX channel X-Git-Tag: v4.20-rc1~81^2~30^2~77 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=b814ec6d453577727e4911331c4e182d80e9ad18;p=linux.git drm/bridge: ti-sn65dsi86: Implement AUX channel This was hand-rolled in the first version, and will surely be useful as we expand the driver to support more varied use cases. Changes in v2: - Change subject prefix s/panel/bridge/ - Downgrade warning in poll function to error message - Fix DP_EDP_CONFIGURATION_SET write value (Sandeep) - Mask upper 8 bits of msg->address (Sandeep) - Check aux cmd status for errors after completing the send (Sandeep) - Remove length check since it's covered in the aux status - Flip the READ check in transfer to WRITE check + early exit Changes in v3: - Added to the set - Wrapped (x) in WDATA/RDATA #defines - Replace readx_poll* with regmap_read_poll* Cc: Sandeep Panda Reviewed-by: Sandeep Panda Signed-off-by: Sean Paul Link: https://patchwork.freedesktop.org/patch/msgid/20180813213058.184821-4-sean@poorly.run --- diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 587d4e4f5674..501f4a81ea5a 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -7,12 +7,14 @@ #include #include #include +#include #include #include #include #include #include #include +#include #include #include #include @@ -46,7 +48,7 @@ #define SN_DATA_FORMAT_REG 0x5B #define SN_HPD_DISABLE_REG 0x5C #define HPD_DISABLE BIT(0) -#define SN_AUX_WDATA0_REG 0x64 +#define SN_AUX_WDATA_REG(x) (0x64 + (x)) #define SN_AUX_ADDR_19_16_REG 0x74 #define SN_AUX_ADDR_15_8_REG 0x75 #define SN_AUX_ADDR_7_0_REG 0x76 @@ -54,6 +56,7 @@ #define SN_AUX_CMD_REG 0x78 #define AUX_CMD_SEND BIT(1) #define AUX_CMD_REQ(x) ((x) << 4) +#define SN_AUX_RDATA_REG(x) (0x79 + (x)) #define SN_SSC_CONFIG_REG 0x93 #define DP_NUM_LANES_MASK GENMASK(5, 4) #define DP_NUM_LANES(x) ((x) << 4) @@ -63,6 +66,10 @@ #define SN_ML_TX_MODE_REG 0x96 #define ML_TX_MAIN_LINK_OFF 0 #define ML_TX_NORMAL_MODE BIT(0) +#define SN_AUX_CMD_STATUS_REG 0xF4 +#define AUX_IRQ_STATUS_AUX_RPLY_TOUT BIT(3) +#define AUX_IRQ_STATUS_AUX_SHORT BIT(5) +#define AUX_IRQ_STATUS_NAT_I2C_FAIL BIT(6) #define MIN_DSI_CLK_FREQ_MHZ 40 @@ -70,11 +77,15 @@ #define DP_CLK_FUDGE_NUM 10 #define DP_CLK_FUDGE_DEN 8 +/* Matches DP_AUX_MAX_PAYLOAD_BYTES (for now) */ +#define SN_AUX_MAX_PAYLOAD_BYTES 16 + #define SN_REGULATOR_SUPPLY_NUM 4 struct ti_sn_bridge { struct device *dev; struct regmap *regmap; + struct drm_dp_aux aux; struct drm_bridge bridge; struct drm_connector connector; struct device_node *host_node; @@ -471,13 +482,8 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge) * authentication method. We need to enable this method in the eDP panel * at DisplayPort address 0x0010A prior to link training. */ - regmap_write(pdata->regmap, SN_AUX_WDATA0_REG, 0x01); - regmap_write(pdata->regmap, SN_AUX_ADDR_19_16_REG, 0x00); - regmap_write(pdata->regmap, SN_AUX_ADDR_15_8_REG, 0x01); - regmap_write(pdata->regmap, SN_AUX_ADDR_7_0_REG, 0x0A); - regmap_write(pdata->regmap, SN_AUX_LENGTH_REG, 0x01); - regmap_write(pdata->regmap, SN_AUX_CMD_REG, 0x81); - usleep_range(10000, 10500); /* 10ms delay recommended by spec */ + drm_dp_dpcd_writeb(&pdata->aux, DP_EDP_CONFIGURATION_SET, + DP_ALTERNATE_SCRAMBLER_RESET_ENABLE); /* Semi auto link training mode */ regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0x0A); @@ -525,6 +531,82 @@ static const struct drm_bridge_funcs ti_sn_bridge_funcs = { .post_disable = ti_sn_bridge_post_disable, }; +static struct ti_sn_bridge *aux_to_ti_sn_bridge(struct drm_dp_aux *aux) +{ + return container_of(aux, struct ti_sn_bridge, aux); +} + +static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux, + struct drm_dp_aux_msg *msg) +{ + struct ti_sn_bridge *pdata = aux_to_ti_sn_bridge(aux); + u32 request = msg->request & ~DP_AUX_I2C_MOT; + u32 request_val = AUX_CMD_REQ(msg->request); + u8 *buf = (u8 *)msg->buffer; + unsigned int val; + int ret, i; + + if (msg->size > SN_AUX_MAX_PAYLOAD_BYTES) + return -EINVAL; + + switch (request) { + case DP_AUX_NATIVE_WRITE: + case DP_AUX_I2C_WRITE: + case DP_AUX_NATIVE_READ: + case DP_AUX_I2C_READ: + regmap_write(pdata->regmap, SN_AUX_CMD_REG, request_val); + break; + default: + return -EINVAL; + } + + regmap_write(pdata->regmap, SN_AUX_ADDR_19_16_REG, + (msg->address >> 16) & 0xF); + regmap_write(pdata->regmap, SN_AUX_ADDR_15_8_REG, + (msg->address >> 8) & 0xFF); + regmap_write(pdata->regmap, SN_AUX_ADDR_7_0_REG, msg->address & 0xFF); + + regmap_write(pdata->regmap, SN_AUX_LENGTH_REG, msg->size); + + if (request == DP_AUX_NATIVE_WRITE || request == DP_AUX_I2C_WRITE) { + for (i = 0; i < msg->size; i++) + regmap_write(pdata->regmap, SN_AUX_WDATA_REG(i), + buf[i]); + } + + regmap_write(pdata->regmap, SN_AUX_CMD_REG, request_val | AUX_CMD_SEND); + + ret = regmap_read_poll_timeout(pdata->regmap, SN_AUX_CMD_REG, val, + !(val & AUX_CMD_SEND), 200, + 50 * 1000); + if (ret) + return ret; + + ret = regmap_read(pdata->regmap, SN_AUX_CMD_STATUS_REG, &val); + if (ret) + return ret; + else if ((val & AUX_IRQ_STATUS_NAT_I2C_FAIL) + || (val & AUX_IRQ_STATUS_AUX_RPLY_TOUT) + || (val & AUX_IRQ_STATUS_AUX_SHORT)) + return -ENXIO; + + if (request == DP_AUX_NATIVE_WRITE || request == DP_AUX_I2C_WRITE) + return msg->size; + + for (i = 0; i < msg->size; i++) { + unsigned int val; + ret = regmap_read(pdata->regmap, SN_AUX_RDATA_REG(i), + &val); + if (ret) + return ret; + + WARN_ON(val & ~0xFF); + buf[i] = (u8)(val & 0xFF); + } + + return msg->size; +} + static int ti_sn_bridge_parse_dsi_host(struct ti_sn_bridge *pdata) { struct device_node *np = pdata->dev->of_node; @@ -604,6 +686,11 @@ static int ti_sn_bridge_probe(struct i2c_client *client, i2c_set_clientdata(client, pdata); + pdata->aux.name = "ti-sn65dsi86-aux"; + pdata->aux.dev = pdata->dev; + pdata->aux.transfer = ti_sn_aux_transfer; + drm_dp_aux_register(&pdata->aux); + pdata->bridge.funcs = &ti_sn_bridge_funcs; pdata->bridge.of_node = client->dev.of_node;