[PATCH v2] drm/bridge: sn65dsi86: Implement AUX channel
Sean Paul
seanpaul at chromium.org
Fri Aug 10 15:55:16 UTC 2018
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 at codeaurora.org>
Signed-off-by: Sean Paul <seanpaul at 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;
--
Sean Paul, Software Engineer, Google / Chromium OS
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