From: Sean Paul <seanpaul@xxxxxxxxxxxx>
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 <spanda@xxxxxxxxxxxxxx>
Signed-off-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
---
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 103 ++++++++++++++++++++++++--
1 file changed, 95 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
index 587d4e4f5674c..501f4a81ea5ab 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>
@@ -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;
