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
Cc: Sandeep Panda spanda@codeaurora.org Signed-off-by: Sean Paul seanpaul@chromium.org --- drivers/gpu/drm/bridge/ti-sn65dsi86.c | 119 ++++++++++++++++++++++++-- 1 file changed, 111 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 1b6e8b72be58..02df26fd0084 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -7,12 +7,14 @@ #include <drm/drm_atomic.h> #include <drm/drm_atomic_helper.h> #include <drm/drm_crtc_helper.h> +#include <drm/drm_dp_helper.h> #include <drm/drm_mipi_dsi.h> #include <drm/drm_of.h> #include <drm/drm_panel.h> #include <linux/clk.h> #include <linux/gpio/consumer.h> #include <linux/i2c.h> +#include <linux/iopoll.h> #include <linux/of_graph.h> #include <linux/pm_runtime.h> #include <linux/regmap.h> @@ -29,12 +31,15 @@ #define SN_DATARATE_CONFIG_REG 0x94 #define SN_PLL_ENABLE_REG 0x0D #define SN_SCRAMBLE_CONFIG_REG 0x95 -#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 #define SN_AUX_LENGTH_REG 0x77 #define SN_AUX_CMD_REG 0x78 +#define AUX_CMD_SEND 0x01 +#define AUX_CMD_REQ(x) (x << 4) +#define SN_AUX_RDATA_REG(x) (0x79 + x) #define SN_ML_TX_MODE_REG 0x96 /* video config specific registers */ #define SN_CHA_ACTIVE_LINE_LENGTH_LOW_REG 0x20 @@ -48,6 +53,10 @@ #define SN_CHA_HORIZONTAL_FRONT_PORCH_REG 0x38 #define SN_CHA_VERTICAL_FRONT_PORCH_REG 0x3A #define SN_DATA_FORMAT_REG 0x5B +#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
@@ -64,6 +73,9 @@ #define SN_DP_DATA_RATE_OFFSET 5 #define SN_SYNC_POLARITY_OFFSET 7
+/* Matches DP_AUX_MAX_PAYLOAD_BYTES (for now) */ +#define SN_AUX_MAX_PAYLOAD_BYTES 16 + #define SN_ENABLE_VID_STREAM_BIT BIT(3) #define SN_REFCLK_FREQ_BITS GENMASK(3, 1) #define SN_DSIA_NUM_LANES_BITS GENMASK(4, 3) @@ -76,6 +88,7 @@ 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; @@ -473,13 +486,8 @@ 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); @@ -527,6 +535,96 @@ 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 bool ti_sn_cmd_done(struct ti_sn_bridge *pdata) +{ + int ret; + unsigned int val; + + ret = regmap_read(pdata->regmap, SN_AUX_CMD_REG, &val); + if (ret) { + DRM_ERROR("Error returned reading AUX_CMD_REG (%d)\n", ret); + return true; + } + + return !(val & AUX_CMD_SEND); +} + +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; + bool cmd_done; + 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 = readx_poll_timeout(ti_sn_cmd_done, pdata, cmd_done, cmd_done, + 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; @@ -606,6 +704,11 @@ 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;