2021-09-18 05:08:54

by Philip Chen

[permalink] [raw]
Subject: [PATCH v4 1/2] drm/bridge: parade-ps8640: Use regmap APIs

Replace the direct i2c access (i2c_smbus_* functions) with regmap APIs,
which will simplify the future update on ps8640 driver.

Reviewed-by: Douglas Anderson <[email protected]>
Signed-off-by: Philip Chen <[email protected]>
---

Changes in v4:
- Remove excessive error logging from the probe function

Changes in v3:
- Fix the nits from v2 review

Changes in v2:
- Add separate reg map config per page

drivers/gpu/drm/bridge/parade-ps8640.c | 94 ++++++++++++++++++--------
1 file changed, 64 insertions(+), 30 deletions(-)

diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c
index 685e9c38b2db..18328e75bf90 100644
--- a/drivers/gpu/drm/bridge/parade-ps8640.c
+++ b/drivers/gpu/drm/bridge/parade-ps8640.c
@@ -9,6 +9,7 @@
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of_graph.h>
+#include <linux/regmap.h>
#include <linux/regulator/consumer.h>

#include <drm/drm_bridge.h>
@@ -31,6 +32,11 @@

#define NUM_MIPI_LANES 4

+#define COMMON_PS8640_REGMAP_CONFIG \
+ .reg_bits = 8, \
+ .val_bits = 8, \
+ .cache_type = REGCACHE_NONE
+
/*
* PS8640 uses multiple addresses:
* page[0]: for DP control
@@ -64,12 +70,48 @@ struct ps8640 {
struct drm_bridge *panel_bridge;
struct mipi_dsi_device *dsi;
struct i2c_client *page[MAX_DEVS];
+ struct regmap *regmap[MAX_DEVS];
struct regulator_bulk_data supplies[2];
struct gpio_desc *gpio_reset;
struct gpio_desc *gpio_powerdown;
bool powered;
};

+static const struct regmap_config ps8640_regmap_config[] = {
+ [PAGE0_DP_CNTL] = {
+ COMMON_PS8640_REGMAP_CONFIG,
+ .max_register = 0xbf,
+ },
+ [PAGE1_VDO_BDG] = {
+ COMMON_PS8640_REGMAP_CONFIG,
+ .max_register = 0xff,
+ },
+ [PAGE2_TOP_CNTL] = {
+ COMMON_PS8640_REGMAP_CONFIG,
+ .max_register = 0xff,
+ },
+ [PAGE3_DSI_CNTL1] = {
+ COMMON_PS8640_REGMAP_CONFIG,
+ .max_register = 0xff,
+ },
+ [PAGE4_MIPI_PHY] = {
+ COMMON_PS8640_REGMAP_CONFIG,
+ .max_register = 0xff,
+ },
+ [PAGE5_VPLL] = {
+ COMMON_PS8640_REGMAP_CONFIG,
+ .max_register = 0x7f,
+ },
+ [PAGE6_DSI_CNTL2] = {
+ COMMON_PS8640_REGMAP_CONFIG,
+ .max_register = 0xff,
+ },
+ [PAGE7_SPI_CNTL] = {
+ COMMON_PS8640_REGMAP_CONFIG,
+ .max_register = 0xff,
+ },
+};
+
static inline struct ps8640 *bridge_to_ps8640(struct drm_bridge *e)
{
return container_of(e, struct ps8640, bridge);
@@ -78,13 +120,13 @@ static inline struct ps8640 *bridge_to_ps8640(struct drm_bridge *e)
static int ps8640_bridge_vdo_control(struct ps8640 *ps_bridge,
const enum ps8640_vdo_control ctrl)
{
- struct i2c_client *client = ps_bridge->page[PAGE3_DSI_CNTL1];
+ struct regmap *map = ps_bridge->regmap[PAGE3_DSI_CNTL1];
u8 vdo_ctrl_buf[] = { VDO_CTL_ADD, ctrl };
int ret;

- ret = i2c_smbus_write_i2c_block_data(client, PAGE3_SET_ADD,
- sizeof(vdo_ctrl_buf),
- vdo_ctrl_buf);
+ ret = regmap_bulk_write(map, PAGE3_SET_ADD,
+ vdo_ctrl_buf, sizeof(vdo_ctrl_buf));
+
if (ret < 0) {
DRM_ERROR("failed to %sable VDO: %d\n",
ctrl == ENABLE ? "en" : "dis", ret);
@@ -96,8 +138,7 @@ static int ps8640_bridge_vdo_control(struct ps8640 *ps_bridge,

static void ps8640_bridge_poweron(struct ps8640 *ps_bridge)
{
- struct i2c_client *client = ps_bridge->page[PAGE2_TOP_CNTL];
- unsigned long timeout;
+ struct regmap *map = ps_bridge->regmap[PAGE2_TOP_CNTL];
int ret, status;

if (ps_bridge->powered)
@@ -121,18 +162,12 @@ static void ps8640_bridge_poweron(struct ps8640 *ps_bridge)
*/
msleep(200);

- timeout = jiffies + msecs_to_jiffies(200) + 1;
-
- while (time_is_after_jiffies(timeout)) {
- status = i2c_smbus_read_byte_data(client, PAGE2_GPIO_H);
- if (status < 0) {
- DRM_ERROR("failed read PAGE2_GPIO_H: %d\n", status);
- goto err_regulators_disable;
- }
- if ((status & PS_GPIO9) == PS_GPIO9)
- break;
+ ret = regmap_read_poll_timeout(map, PAGE2_GPIO_H, status,
+ status & PS_GPIO9, 20 * 1000, 200 * 1000);

- msleep(20);
+ if (ret < 0) {
+ DRM_ERROR("failed read PAGE2_GPIO_H: %d\n", ret);
+ goto err_regulators_disable;
}

msleep(50);
@@ -144,22 +179,15 @@ static void ps8640_bridge_poweron(struct ps8640 *ps_bridge)
* disabled by the manufacturer. Once disabled, all MCS commands are
* ignored by the display interface.
*/
- status = i2c_smbus_read_byte_data(client, PAGE2_MCS_EN);
- if (status < 0) {
- DRM_ERROR("failed read PAGE2_MCS_EN: %d\n", status);
- goto err_regulators_disable;
- }

- ret = i2c_smbus_write_byte_data(client, PAGE2_MCS_EN,
- status & ~MCS_EN);
+ ret = regmap_update_bits(map, PAGE2_MCS_EN, MCS_EN, 0);
if (ret < 0) {
DRM_ERROR("failed write PAGE2_MCS_EN: %d\n", ret);
goto err_regulators_disable;
}

/* Switch access edp panel's edid through i2c */
- ret = i2c_smbus_write_byte_data(client, PAGE2_I2C_BYPASS,
- I2C_BYPASS_EN);
+ ret = regmap_write(map, PAGE2_I2C_BYPASS, I2C_BYPASS_EN);
if (ret < 0) {
DRM_ERROR("failed write PAGE2_I2C_BYPASS: %d\n", ret);
goto err_regulators_disable;
@@ -362,15 +390,21 @@ static int ps8640_probe(struct i2c_client *client)

ps_bridge->page[PAGE0_DP_CNTL] = client;

+ ps_bridge->regmap[PAGE0_DP_CNTL] = devm_regmap_init_i2c(client, ps8640_regmap_config);
+ if (IS_ERR(ps_bridge->regmap[PAGE0_DP_CNTL]))
+ return PTR_ERR(ps_bridge->regmap[PAGE0_DP_CNTL]);
+
for (i = 1; i < ARRAY_SIZE(ps_bridge->page); i++) {
ps_bridge->page[i] = devm_i2c_new_dummy_device(&client->dev,
client->adapter,
client->addr + i);
- if (IS_ERR(ps_bridge->page[i])) {
- dev_err(dev, "failed i2c dummy device, address %02x\n",
- client->addr + i);
+ if (IS_ERR(ps_bridge->page[i]))
return PTR_ERR(ps_bridge->page[i]);
- }
+
+ ps_bridge->regmap[i] = devm_regmap_init_i2c(ps_bridge->page[i],
+ ps8640_regmap_config + i);
+ if (IS_ERR(ps_bridge->regmap[i]))
+ return PTR_ERR(ps_bridge->regmap[i]);
}

i2c_set_clientdata(client, ps_bridge);
--
2.33.0.464.g1972c5931b-goog


2021-09-18 05:10:08

by Philip Chen

[permalink] [raw]
Subject: [PATCH v4 2/2] drm/bridge: parade-ps8640: Add support for AUX channel

Implement the first version of AUX support, which will be useful as
we expand the driver to support varied use cases.

Signed-off-by: Philip Chen <[email protected]>
---

Changes in v4:
- Fix aux_transfer function:
- Replace dev_err with DRM_DEV_ERROR
- Reorg the bit manipulation around address/len/request registers
- Make SWAUX_STATUS_I2C_NACK fall through to SWAUX_STATUS_ACKM and

Changes in v3:
- Verify with HW and thus remove WARNING from the patch description
- Fix the reg names to better match the manual
- Fix aux_transfer function:
- Fix the switch statement which handles aux request
- Write the original (unstripped) aux request code to the register
- Replace DRM_ERROR with dev_err
- Remove goto and just return ret
- Fix the switch statement which handles aux status
- When reading returned data, read from RDATA instead of WDATA
- Fix attach function:
- Call mipi_dsi_detach() when aux_register fails

Changes in v2:
- Handle the case where an AUX transaction has no payload
- Add a reg polling for p0.0x83 to confirm AUX cmd is issued and
read data is returned
- Replace regmap_noinc_read/write with looped regmap_read/write,
as regmap_noinc_read/write doesn't read one byte at a time unless
max_raw_read/write is set to 1.
- Register/Unregister the AUX device explicitly when the bridge is
attached/detached
- Remove the use of runtime PM
- Program AUX addr/cmd/len in a single regmap_bulk_write()
- Add newlines for DRM_ERROR messages

drivers/gpu/drm/bridge/parade-ps8640.c | 181 ++++++++++++++++++++++++-
1 file changed, 180 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c
index 18328e75bf90..31ec4a64de91 100644
--- a/drivers/gpu/drm/bridge/parade-ps8640.c
+++ b/drivers/gpu/drm/bridge/parade-ps8640.c
@@ -13,11 +13,37 @@
#include <linux/regulator/consumer.h>

#include <drm/drm_bridge.h>
+#include <drm/drm_dp_helper.h>
#include <drm/drm_mipi_dsi.h>
#include <drm/drm_of.h>
#include <drm/drm_panel.h>
#include <drm/drm_print.h>

+#define PAGE0_AUXCH_CFG3 0x76
+#define AUXCH_CFG3_RESET 0xff
+#define PAGE0_SWAUX_ADDR_7_0 0x7d
+#define PAGE0_SWAUX_ADDR_15_8 0x7e
+#define PAGE0_SWAUX_ADDR_23_16 0x7f
+#define SWAUX_ADDR_19_16_MASK GENMASK(3, 0)
+#define SWAUX_CMD_MASK GENMASK(7, 4)
+#define PAGE0_SWAUX_LENGTH 0x80
+#define SWAUX_LENGTH_MASK GENMASK(3, 0)
+#define SWAUX_NO_PAYLOAD BIT(7)
+#define PAGE0_SWAUX_WDATA 0x81
+#define PAGE0_SWAUX_RDATA 0x82
+#define PAGE0_SWAUX_CTRL 0x83
+#define SWAUX_SEND BIT(0)
+#define PAGE0_SWAUX_STATUS 0x84
+#define SWAUX_M_MASK GENMASK(4, 0)
+#define SWAUX_STATUS_MASK GENMASK(7, 5)
+#define SWAUX_STATUS_NACK (0x1 << 5)
+#define SWAUX_STATUS_DEFER (0x2 << 5)
+#define SWAUX_STATUS_ACKM (0x3 << 5)
+#define SWAUX_STATUS_INVALID (0x4 << 5)
+#define SWAUX_STATUS_I2C_NACK (0x5 << 5)
+#define SWAUX_STATUS_I2C_DEFER (0x6 << 5)
+#define SWAUX_STATUS_TIMEOUT (0x7 << 5)
+
#define PAGE2_GPIO_H 0xa7
#define PS_GPIO9 BIT(1)
#define PAGE2_I2C_BYPASS 0xea
@@ -68,6 +94,7 @@ enum ps8640_vdo_control {
struct ps8640 {
struct drm_bridge bridge;
struct drm_bridge *panel_bridge;
+ struct drm_dp_aux aux;
struct mipi_dsi_device *dsi;
struct i2c_client *page[MAX_DEVS];
struct regmap *regmap[MAX_DEVS];
@@ -117,6 +144,136 @@ static inline struct ps8640 *bridge_to_ps8640(struct drm_bridge *e)
return container_of(e, struct ps8640, bridge);
}

+static inline struct ps8640 *aux_to_ps8640(struct drm_dp_aux *aux)
+{
+ return container_of(aux, struct ps8640, aux);
+}
+
+static ssize_t ps8640_aux_transfer(struct drm_dp_aux *aux,
+ struct drm_dp_aux_msg *msg)
+{
+ struct ps8640 *ps_bridge = aux_to_ps8640(aux);
+ struct regmap *map = ps_bridge->regmap[PAGE0_DP_CNTL];
+ struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;
+
+ unsigned int len = msg->size;
+ unsigned int data;
+ unsigned int addr_base;
+ int ret;
+ u8 request = msg->request &
+ ~(DP_AUX_I2C_MOT | DP_AUX_I2C_WRITE_STATUS_UPDATE);
+ u8 *buf = msg->buffer;
+ u8 addr_len[PAGE0_SWAUX_LENGTH + 1 - PAGE0_SWAUX_ADDR_7_0];
+ u8 i;
+ bool is_native_aux = false;
+
+ if (len > DP_AUX_MAX_PAYLOAD_BYTES)
+ return -EINVAL;
+
+ switch (request) {
+ case DP_AUX_NATIVE_WRITE:
+ case DP_AUX_NATIVE_READ:
+ is_native_aux = true;
+ fallthrough;
+ case DP_AUX_I2C_WRITE:
+ case DP_AUX_I2C_READ:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ret = regmap_write(map, PAGE0_AUXCH_CFG3, AUXCH_CFG3_RESET);
+ if (ret) {
+ DRM_DEV_ERROR(dev, "failed to write PAGE0_AUXCH_CFG3: %d\n",
+ ret);
+ return ret;
+ }
+
+ /* Assume it's good */
+ msg->reply = 0;
+
+ addr_base = PAGE0_SWAUX_ADDR_7_0;
+ addr_len[PAGE0_SWAUX_ADDR_7_0 - base] = msg->address;
+ addr_len[PAGE0_SWAUX_ADDR_15_8 - base] = msg->address >> 8;
+ addr_len[PAGE0_SWAUX_ADDR_23_16 - base] = (msg->address >> 16) &
+ SWAUX_ADDR_19_16_MASK
+ addr_len[PAGE0_SWAUX_ADDR_23_16 - base] |= (msg->request << 4) &
+ SWAUX_CMD_MASK;
+ addr_len[PAGE0_SWAUX_LENGTH - base] = (len == 0) ? SWAUX_NO_PAYLOAD :
+ ((len - 1) & SWAUX_LENGTH_MASK);
+
+ regmap_bulk_write(map, PAGE0_SWAUX_ADDR_7_0, addr_len,
+ ARRAY_SIZE(addr_len));
+
+ if (len && (request == DP_AUX_NATIVE_WRITE ||
+ request == DP_AUX_I2C_WRITE)) {
+ /* Write to the internal FIFO buffer */
+ for (i = 0; i < len; i++) {
+ ret = regmap_write(map, PAGE0_SWAUX_WDATA, buf[i]);
+ if (ret) {
+ DRM_DEV_ERROR(dev,
+ "failed to write WDATA: %d\n",
+ ret);
+ return ret;
+ }
+ }
+ }
+
+ regmap_write(map, PAGE0_SWAUX_CTRL, SWAUX_SEND);
+
+ /* Zero delay loop because i2c transactions are slow already */
+ regmap_read_poll_timeout(map, PAGE0_SWAUX_CTRL, data,
+ !(data & SWAUX_SEND), 0, 50 * 1000);
+
+ regmap_read(map, PAGE0_SWAUX_STATUS, &data);
+ if (ret) {
+ DRM_DEV_ERROR(dev, "failed to read PAGE0_SWAUX_STATUS: %d\n",
+ ret);
+ return ret;
+ }
+
+ switch (data & SWAUX_STATUS_MASK) {
+ /* Ignore the DEFER cases as they are already handled in hardware */
+ case SWAUX_STATUS_NACK:
+ case SWAUX_STATUS_I2C_NACK:
+ /*
+ * The programming guide is not clear about whether a I2C NACK
+ * would trigger SWAUX_STATUS_NACK or SWAUX_STATUS_I2C_NACK. So
+ * we handle both cases together.
+ */
+ if (is_native_aux)
+ msg->reply |= DP_AUX_NATIVE_REPLY_NACK;
+ else
+ msg->reply |= DP_AUX_I2C_REPLY_NACK;
+
+ fallthrough;
+ case SWAUX_STATUS_ACKM:
+ len = data & SWAUX_M_MASK;
+ break;
+ case SWAUX_STATUS_INVALID:
+ return -EOPNOTSUPP;
+ case SWAUX_STATUS_TIMEOUT:
+ return -ETIMEDOUT;
+ }
+
+ if (len && (request == DP_AUX_NATIVE_READ ||
+ request == DP_AUX_I2C_READ)) {
+ /* Read from the internal FIFO buffer */
+ for (i = 0; i < len; i++) {
+ ret = regmap_read(map, PAGE0_SWAUX_RDATA,
+ (unsigned int *)(buf + i));
+ if (ret) {
+ DRM_DEV_ERROR(dev,
+ "failed to read RDATA: %d\n",
+ ret);
+ return ret;
+ }
+ }
+ }
+
+ return len;
+}
+
static int ps8640_bridge_vdo_control(struct ps8640 *ps_bridge,
const enum ps8640_vdo_control ctrl)
{
@@ -286,18 +443,34 @@ static int ps8640_bridge_attach(struct drm_bridge *bridge,
dsi->format = MIPI_DSI_FMT_RGB888;
dsi->lanes = NUM_MIPI_LANES;
ret = mipi_dsi_attach(dsi);
- if (ret)
+ if (ret) {
+ dev_err(dev, "failed to attach dsi device: %d\n", ret);
goto err_dsi_attach;
+ }
+
+ ret = drm_dp_aux_register(&ps_bridge->aux);
+ if (ret) {
+ dev_err(dev, "failed to register DP AUX channel: %d\n", ret);
+ goto err_aux_register;
+ }

/* Attach the panel-bridge to the dsi bridge */
return drm_bridge_attach(bridge->encoder, ps_bridge->panel_bridge,
&ps_bridge->bridge, flags);

+err_aux_register:
+ mipi_dsi_detach(dsi);
err_dsi_attach:
mipi_dsi_device_unregister(dsi);
return ret;
}

+
+static void ps8640_bridge_detach(struct drm_bridge *bridge)
+{
+ drm_dp_aux_unregister(&bridge_to_ps8640(bridge)->aux);
+}
+
static struct edid *ps8640_bridge_get_edid(struct drm_bridge *bridge,
struct drm_connector *connector)
{
@@ -334,6 +507,7 @@ static struct edid *ps8640_bridge_get_edid(struct drm_bridge *bridge,

static const struct drm_bridge_funcs ps8640_bridge_funcs = {
.attach = ps8640_bridge_attach,
+ .detach = ps8640_bridge_detach,
.get_edid = ps8640_bridge_get_edid,
.post_disable = ps8640_post_disable,
.pre_enable = ps8640_pre_enable,
@@ -409,6 +583,11 @@ static int ps8640_probe(struct i2c_client *client)

i2c_set_clientdata(client, ps_bridge);

+ ps_bridge->aux.name = "parade-ps8640-aux";
+ ps_bridge->aux.dev = dev;
+ ps_bridge->aux.transfer = ps8640_aux_transfer;
+ drm_dp_aux_init(&ps_bridge->aux);
+
drm_bridge_add(&ps_bridge->bridge);

return 0;
--
2.33.0.464.g1972c5931b-goog