Commit b814ec6d authored by Sean Paul's avatar Sean Paul
Browse files

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 <spanda@codeaurora.org>
Reviewed-by: default avatarSandeep Panda <spanda@codeaurora.org>
Signed-off-by: default avatarSean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180813213058.184821-4-sean@poorly.run
parent 6c76c0eb

drivers/gpu/drm/bridge/ti-sn65dsi86.c

+95 −8
Original line number Diff line number Diff line
@@ -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;