From: "Hermes.Wu" <hermes...@ite.com.tw>

add AUX-I2C functionality to support MCCS. 

Change-Id: I63e1a0e5da67526f89f35605a82944be67dee8ac
Signed-off-by: Hermes Wu <hermes...@ite.com.tw>
---
 drivers/gpu/drm/bridge/ite-it6505.c | 209 ++++++++++++++++++++++++++--
 1 file changed, 200 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c 
b/drivers/gpu/drm/bridge/ite-it6505.c
index cef02c8c363e..1a272c67e82b 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -127,6 +127,9 @@
 #define REG_AUX_ADR_16_19 0x26
 #define REG_AUX_OUT_DATA0 0x27
 
+#define REG_AUX_I2C_ADR 0x25
+#define REG_AUX_I2C_OP 0x26
+
 #define REG_AUX_CMD_REQ 0x2B
 #define AUX_BUSY BIT(5)
 
@@ -268,6 +271,19 @@
 #define REG_SSC_CTRL1 0x189
 #define REG_SSC_CTRL2 0x18A
 
+#define REG_AUX_USER_CTRL 0x190
+#define EN_USER_AUX BIT(0)
+#define USER_AUX_DONE BIT(1)
+#define AUX_EVENT BIT(4)
+
+#define REG_AUX_USER_DATA_REC 0x191
+#define M_AUX_IN_REC   0xF0
+#define M_AUX_OUT_REC  0x0F
+
+#define REG_AUX_USER_TXB 0x190
+#define REG_AUX_USER_REPLY 0x19A
+#define REG_AUX_USER_RXB(n) (n + 0x19B)
+
 #define RBR DP_LINK_BW_1_62
 #define HBR DP_LINK_BW_2_7
 #define HBR2 DP_LINK_BW_5_4
@@ -303,6 +319,8 @@
 #define MAX_EQ_LEVEL 0x03
 #define AUX_WAIT_TIMEOUT_MS 15
 #define AUX_FIFO_MAX_SIZE 16
+#define AUX_I2C_MAX_SIZE 4
+#define AUX_I2C_DEFER_RETRY 4
 #define PIXEL_CLK_DELAY 1
 #define PIXEL_CLK_INVERSE 0
 #define ADJUST_PHASE_THRESHOLD 80000
@@ -325,7 +343,12 @@
 enum aux_cmd_type {
        CMD_AUX_NATIVE_READ = 0x0,
        CMD_AUX_NATIVE_WRITE = 0x5,
+       CMD_AUX_GI2C_ADR = 0x08,
+       CMD_AUX_GI2C_READ = 0x09,
+       CMD_AUX_GI2C_WRITE = 0x0A,
        CMD_AUX_I2C_EDID_READ = 0xB,
+       CMD_AUX_I2C_READ = 0x0D,
+       CMD_AUX_I2C_WRITE = 0x0C,
 
        /*extend read ncommand */
        CMD_AUX_GET_KSV_LIST = 0x10,
@@ -333,8 +356,11 @@ enum aux_cmd_type {
 
 enum aux_cmd_reply {
        REPLY_ACK,
-       REPLY_NACK,
-       REPLY_DEFER,
+       REPLY_NACK = 1,
+       REPLY_DEFER = 2,
+
+       REPLY_I2C_NACK = 4,
+       REPLY_I2C_DEFER = 8,
 };
 
 enum link_train_status {
@@ -1087,7 +1113,6 @@ static ssize_t it6505_aux_do_transfer(struct it6505 
*it6505,
                                      size_t size, enum aux_cmd_reply *reply)
 {
        int i, ret_size, ret = 0, request_size;
-       struct device *dev = &it6505->client->dev;
 
        mutex_lock(&it6505->aux_lock);
        for (i = 0; i < size; ) {
@@ -1114,6 +1139,168 @@ static ssize_t it6505_aux_do_transfer(struct it6505 
*it6505,
        return ret;
 }
 
+
+static int it6505_aux_i2c_wait(struct it6505 *it6505, u8 *reply)
+{
+       int err = 0;
+       unsigned long timeout;
+       struct device *dev = &it6505->client->dev;
+
+       timeout = jiffies + msecs_to_jiffies(AUX_WAIT_TIMEOUT_MS) + 1;
+
+       do {
+               if (it6505_read(it6505, REG_AUX_USER_CTRL) & AUX_EVENT)
+                       break;
+               if (time_after(jiffies, timeout)) {
+                       dev_err(dev, "Timed out waiting AUX I2C, BUSY = %X\n",
+                                       it6505_aux_op_finished(it6505));
+                       err = -ETIMEDOUT;
+                       goto end_aux_i2c_wait;
+               }
+               usleep_range(300, 800);
+
+       } while (!it6505_aux_op_finished(it6505));
+
+       if (reply == NULL)
+               goto end_aux_i2c_wait;
+
+       *reply = it6505_read(it6505, REG_AUX_USER_REPLY) >> 4;
+
+       if (*reply == 0)
+               goto end_aux_i2c_wait;
+
+       if ((*reply == DP_AUX_NATIVE_REPLY_DEFER) ||
+                       (*reply == DP_AUX_I2C_REPLY_DEFER))
+               err = -EBUSY;
+       else if ((*reply == DP_AUX_NATIVE_REPLY_NACK) ||
+                       (*reply == DP_AUX_I2C_REPLY_NACK))
+               err = -ENXIO;
+
+end_aux_i2c_wait:
+       it6505_set_bits(it6505, REG_AUX_USER_CTRL, USER_AUX_DONE, 
USER_AUX_DONE);
+       return err;
+}
+
+static int it6505_aux_i2c_readb(struct it6505 *it6505, u8 *buf, size_t size, 
u8 *reply)
+{
+       int ret, i;
+       int retry = 0;
+
+       for (retry = 0; retry < AUX_I2C_DEFER_RETRY; retry++) {
+
+               it6505_write(it6505, REG_AUX_CMD_REQ, CMD_AUX_GI2C_READ);
+
+               ret = it6505_aux_i2c_wait(it6505, reply);
+
+               if ((*reply == DP_AUX_NATIVE_REPLY_DEFER) ||
+                       (*reply == DP_AUX_I2C_REPLY_DEFER))
+                       continue;
+
+               if (ret >= 0)
+                       break;
+       }
+
+       for (i = 0; i < size; i++)
+               buf[i] =  (u8) it6505_read(it6505, REG_AUX_USER_RXB(0 + i));
+
+       return size;
+}
+
+static int it6505_aux_i2c_writeb(struct it6505 *it6505, u8 *buf, size_t size, 
u8 *reply)
+{
+       int i, ret;
+       int retry = 0;
+
+       for (i = 0; i < size; i++)
+               it6505_write(it6505, REG_AUX_OUT_DATA0 + i, buf[i]);
+
+       for (retry = 0; retry < AUX_I2C_DEFER_RETRY; retry++) {
+
+               it6505_write(it6505, REG_AUX_CMD_REQ, CMD_AUX_GI2C_WRITE);
+
+               ret = it6505_aux_i2c_wait(it6505, reply);
+
+               if ((*reply == DP_AUX_NATIVE_REPLY_DEFER) ||
+                       (*reply == DP_AUX_I2C_REPLY_DEFER))
+                       continue;
+
+               if (ret >= 0)
+                       break;
+       }
+       return size;
+}
+
+static ssize_t it6505_aux_i2c_operation(struct it6505 *it6505,
+                                       struct drm_dp_aux_msg *msg)
+{
+       int ret;
+       ssize_t request_size, data_cnt = 0;
+       struct device *dev = &it6505->client->dev;
+       u8 *buffer = msg->buffer;
+
+       /* set AUX user mode */
+       it6505_set_bits(it6505, REG_AUX_CTRL,
+                       AUX_USER_MODE | AUX_NO_SEGMENT_WR, AUX_USER_MODE);
+       it6505_set_bits(it6505, REG_AUX_USER_CTRL, EN_USER_AUX, EN_USER_AUX);
+       /* clear AUX FIFO */
+       it6505_set_bits(it6505, REG_AUX_CTRL,
+                       AUX_EN_FIFO_READ | CLR_EDID_FIFO,
+                       AUX_EN_FIFO_READ | CLR_EDID_FIFO);
+
+       it6505_set_bits(it6505, REG_AUX_CTRL,
+                       AUX_EN_FIFO_READ | CLR_EDID_FIFO, 0x00);
+
+       it6505_write(it6505, REG_AUX_ADR_0_7, 0x00);
+       it6505_write(it6505, REG_AUX_I2C_ADR, msg->address << 1);
+
+       if (msg->size == 0) {
+               /* IIC Start/STOP dummy write */
+               it6505_write(it6505, REG_AUX_I2C_OP, msg->request);
+               it6505_write(it6505, REG_AUX_CMD_REQ, CMD_AUX_GI2C_ADR);
+               ret = it6505_aux_i2c_wait(it6505, &msg->reply);
+               goto end_aux_i2c_transfer;
+       }
+
+       /* IIC data transfer */
+       for (data_cnt = 0; data_cnt < msg->size; ) {
+               request_size = min(msg->size - data_cnt, AUX_I2C_MAX_SIZE);
+               it6505_write(it6505, REG_AUX_I2C_OP,
+                                       (msg->request) | ((request_size - 1) << 
4));
+
+               if ((msg->request & DP_AUX_I2C_READ) == DP_AUX_I2C_READ)
+                       ret = it6505_aux_i2c_readb(it6505, &buffer[data_cnt],
+                                                       request_size, 
&msg->reply);
+               else
+                       ret = it6505_aux_i2c_writeb(it6505, &buffer[data_cnt],
+                                                       request_size, 
&msg->reply);
+
+               if (ret < 0)
+                       goto end_aux_i2c_transfer;
+
+               data_cnt += request_size;
+       }
+       ret = data_cnt;
+end_aux_i2c_transfer:
+
+       it6505_set_bits(it6505, REG_AUX_USER_CTRL, EN_USER_AUX, 0);
+       it6505_set_bits(it6505, REG_AUX_CTRL, AUX_USER_MODE, 0);
+       return ret;
+}
+
+
+static ssize_t it6505_aux_i2c_transfer(struct drm_dp_aux *aux,
+                                  struct drm_dp_aux_msg *msg)
+{
+       struct it6505 *it6505 = container_of(aux, struct it6505, aux);
+       int ret;
+
+       mutex_lock(&it6505->aux_lock);
+       ret = it6505_aux_i2c_operation(it6505, msg);
+       mutex_unlock(&it6505->aux_lock);
+       return ret;
+}
+
+
 static ssize_t it6505_aux_transfer(struct drm_dp_aux *aux,
                                   struct drm_dp_aux_msg *msg)
 {
@@ -1125,7 +1312,7 @@ static ssize_t it6505_aux_transfer(struct drm_dp_aux *aux,
 
        /* IT6505 doesn't support arbitrary I2C read / write. */
        if (is_i2c)
-               return -EINVAL;
+               return it6505_aux_i2c_transfer(aux, msg);
 
        switch (msg->request) {
        case DP_AUX_NATIVE_READ:
@@ -1153,6 +1340,8 @@ static ssize_t it6505_aux_transfer(struct drm_dp_aux *aux,
        case REPLY_DEFER:
                msg->reply = DP_AUX_NATIVE_REPLY_DEFER;
                break;
+       default:
+               break;
        }
 
        return ret;
@@ -1180,7 +1369,7 @@ static int it6505_get_edid_block(void *data, u8 *buf, 
unsigned int block,
                switch (reply) {
                case REPLY_ACK:
                        DRM_DEV_DEBUG_DRIVER(dev, "[0x%02x]: %8ph", offset,
-                                            buf + offset);
+                                                               uf + offset);
                        offset += 8;
                        aux_retry = 100;
                        break;
@@ -1190,6 +1379,8 @@ static int it6505_get_edid_block(void *data, u8 *buf, 
unsigned int block,
                        msleep(20);
                        if (!(--aux_retry))
                                return -EIO;
+               default:
+                       break;
                }
        }
 
@@ -2031,8 +2222,8 @@ static int it6505_setup_sha1_input(struct it6505 *it6505, 
u8 *sha1_input)
 
 
        err =  it6505_get_ksvlist(it6505, sha1_input, down_stream_count * 5);
-       if (err < 0)
-               return err;
+               if (err < 0)
+                       return err;
 
        msg_count += down_stream_count * 5;
 
@@ -2075,7 +2266,7 @@ static bool it6505_hdcp_part2_ksvlist_check(struct it6505 
*it6505)
        for (retry = 0; retry < 3; retry++) {
 
                err = it6505_get_dpcd(it6505, DP_AUX_HDCP_V_PRIME(0), (u8 *)bv,
-                                       sizeof(bv));
+                             sizeof(bv));
 
                if (err < 0) {
                        dev_err(dev, "Read V' value Fail %d", retry);
@@ -2126,7 +2317,7 @@ static void it6505_hdcp_wait_ksv_list(struct work_struct 
*work)
 
        ksv_list_check = it6505_hdcp_part2_ksvlist_check(it6505);
        DRM_DEV_DEBUG_DRIVER(dev, "ksv list ready, ksv list check %s",
-                               ksv_list_check ? "pass" : "fail");
+                            ksv_list_check ? "pass" : "fail");
 
        if (ksv_list_check)
                return;
-- 
2.34.1

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