From: baihan li <libaihan@xxxxxxxxxx>
Add dp aux read/write functions. They are basic functions
and will be used later.
Signed-off-by: baihan li <libaihan@xxxxxxxxxx>
---
ChangeLog:
v1 -> v2:
- using drm_dp_aux frame implement dp aux read and write functions, suggested by Jani Nikula.
- using drm dp header files' dp macros instead, suggested by Andy Yan.
v1:https://lore.kernel.org/all/20240930100610.782363-1-shiyongbang@xxxxxxxxxx/
---
drivers/gpu/drm/hisilicon/hibmc/Makefile | 3 +-
drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c | 162 +++++++++++++++++++
drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.h | 31 ++++
drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h | 74 +++++++++
drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h | 76 +++++++++
5 files changed, 345 insertions(+), 1 deletion(-)
create mode 100644 drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c
create mode 100644 drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.h
create mode 100644 drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h
create mode 100644 drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h
diff --git a/drivers/gpu/drm/hisilicon/hibmc/Makefile b/drivers/gpu/drm/hisilicon/hibmc/Makefile
index d25c75e60d3d..8770ec6dfffd 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/Makefile
+++ b/drivers/gpu/drm/hisilicon/hibmc/Makefile
@@ -1,4 +1,5 @@
# SPDX-License-Identifier: GPL-2.0-only
-hibmc-drm-y := hibmc_drm_drv.o hibmc_drm_de.o hibmc_drm_vdac.o hibmc_drm_i2c.o
+hibmc-drm-y := hibmc_drm_drv.o hibmc_drm_de.o hibmc_drm_vdac.o hibmc_drm_i2c.o \
+ dp/dp_aux.o
obj-$(CONFIG_DRM_HISI_HIBMC) += hibmc-drm.o
diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c
new file mode 100644
index 000000000000..0078cafdf86d
--- /dev/null
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c
@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+// Copyright (c) 2024 Hisilicon Limited.
+
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/minmax.h>
+#include <drm/drm_device.h>
+#include <drm/drm_print.h>
+#include "dp_comm.h"
+#include "dp_reg.h"
+#include "dp_aux.h"
+
+#define DP_MIN_PULSE_NUM 0x9
+
+static void dp_aux_reset(const struct dp_dev *dp)
+{
+ dp_write_bits(dp->base + DP_DPTX_RST_CTRL, DP_CFG_AUX_RST_N, 0x0);
+ usleep_range(10, 15);
+ dp_write_bits(dp->base + DP_DPTX_RST_CTRL, DP_CFG_AUX_RST_N, 0x1);
+}
+
+static void dp_aux_read_data(struct dp_dev *dp, u8 *buf, u8 size)
+{
+ u32 reg_num;
+ u32 value;
+ u32 num;
+ u8 i, j;
+
+ reg_num = round_up(size, AUX_4_BYTE) / AUX_4_BYTE;
+ for (i = 0; i < reg_num; i++) {
+ /* number of bytes read from a single register */
+ num = min(size - i * AUX_4_BYTE, AUX_4_BYTE);
+ value = readl(dp->base + DP_AUX_RD_DATA0 + i * AUX_4_BYTE);
+ /* convert the 32-bit value of the register to the buffer. */
+ for (j = 0; j < num; j++)
+ buf[i * AUX_4_BYTE + j] = value >> (j * AUX_8_BIT);
+ }
+}
+
+static void dp_aux_write_data(struct dp_dev *dp, u8 *buf, u8 size)
+{
+ u32 reg_num;
+ u32 value;
+ u8 i, j;
+ u32 num;
+
+ reg_num = round_up(size, AUX_4_BYTE) / AUX_4_BYTE;
+ for (i = 0; i < reg_num; i++) {
+ /* number of bytes written to a single register */
+ num = min_t(u8, size - i * AUX_4_BYTE, AUX_4_BYTE);
+ value = 0;
+ /* obtain the 32-bit value written to a single register. */
+ for (j = 0; j < num; j++)
+ value |= buf[i * AUX_4_BYTE + j] << (j * AUX_8_BIT);
+ /* writing data to a single register */
+ writel(value, dp->base + DP_AUX_WR_DATA0 + i * AUX_4_BYTE);
+ }
+}
+
+static u32 dp_aux_build_cmd(const struct drm_dp_aux_msg *msg)
+{
+ u32 aux_cmd = msg->request;
+
+ if (msg->size)
+ aux_cmd |= (msg->size - 1) << AUX_CMD_REQ_LEN_S;
+ else
+ aux_cmd |= 1 << AUX_CMD_I2C_ADDR_ONLY_S;
+
+ aux_cmd |= msg->address << AUX_CMD_ADDR_S;
+
+ return aux_cmd;
+}
+
+/* ret >= 0 ,ret is size; ret < 0, ret is err code */
+static int dp_aux_parse_xfer(struct dp_dev *dp, struct drm_dp_aux_msg *msg)
+{
+ u32 buf_data_cnt;
+ u32 aux_status;
+ int ret = 0;
+
+ aux_status = readl(dp->base + DP_AUX_STATUS);
+ msg->reply = FIELD_GET(DP_CFG_AUX_STATUS, aux_status);
+
+ if (aux_status & DP_CFG_AUX_TIMEOUT)
+ return -ETIMEDOUT;
+
+ /* only address */
+ if (!msg->size)
+ return 0;
+
+ if (msg->reply != DP_AUX_NATIVE_REPLY_ACK)
+ return 0;
+
+ buf_data_cnt = FIELD_GET(DP_CFG_AUX_READY_DATA_BYTE, aux_status);
+
+ switch (msg->request) {
+ case DP_AUX_NATIVE_WRITE:
+ ret = msg->size;
+ break;
+ case DP_AUX_I2C_WRITE | DP_AUX_I2C_MOT:
+ if (buf_data_cnt == AUX_I2C_WRITE_SUCCESS)
+ ret = msg->size;
+ else if (buf_data_cnt == AUX_I2C_WRITE_PARTIAL_SUCCESS)
+ ret = FIELD_GET(DP_CFG_AUX, aux_status);
+ break;
+ case DP_AUX_NATIVE_READ:
+ case DP_AUX_I2C_READ | DP_AUX_I2C_MOT:
+ buf_data_cnt--;
+ /* only the successful part of data is read */
+ if (buf_data_cnt != msg->size) {
+ ret = -EBUSY;
+ } else { /* all data is successfully read */
+ dp_aux_read_data(dp, msg->buffer, msg->size);
+ ret = msg->size;
+ }
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return ret;
+}
+
+/* ret >= 0 ,ret is size; ret < 0, ret is err code */
+static ssize_t dp_aux_xfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
+{
+ struct dp_dev *dp = container_of(aux, struct dp_dev, aux);
+ u32 aux_cmd;
+ int ret;
+ u32 val; /* val will be assigned at the beginning of readl_poll_timeout function */
+
+ writel(0, dp->base + DP_AUX_WR_DATA0);
+ writel(0, dp->base + DP_AUX_WR_DATA1);
+ writel(0, dp->base + DP_AUX_WR_DATA2);
+ writel(0, dp->base + DP_AUX_WR_DATA3);
+
+ dp_aux_write_data(dp, msg->buffer, msg->size);
+
+ aux_cmd = dp_aux_build_cmd(msg);
+ writel(aux_cmd, dp->base + DP_AUX_CMD_ADDR);
+
+ /* enable aux transfer */
+ dp_write_bits(dp->base + DP_AUX_REQ, DP_CFG_AUX_REQ, 0x1);
+ ret = readl_poll_timeout(dp->base + DP_AUX_REQ, val, !(val & DP_CFG_AUX_REQ), 50, 5000);
+ if (ret) {
+ dp_aux_reset(dp);
+ return ret;
+ }
+
+ return dp_aux_parse_xfer(dp, msg);
+}
+
+void dp_aux_init(struct dp_dev *dp)
+{
+ dp_write_bits(dp->base + DP_AUX_REQ, DP_CFG_AUX_SYNC_LEN_SEL, 0x0);
+ dp_write_bits(dp->base + DP_AUX_REQ, DP_CFG_AUX_TIMER_TIMEOUT, 0x1);
+ dp_write_bits(dp->base + DP_AUX_REQ, DP_CFG_AUX_MIN_PULSE_NUM, DP_MIN_PULSE_NUM);
+
+ dp->aux.transfer = dp_aux_xfer;
+ dp->aux.is_remote = 0;
+ drm_dp_aux_init(&dp->aux);
+}
diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.h b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.h
new file mode 100644
index 000000000000..6f95a3750d60
--- /dev/null
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (c) 2024 Hisilicon Limited. */
+
+#ifndef DP_AUX_H
+#define DP_AUX_H
+
+#include <linux/bitops.h>
+#include "dp_comm.h"
+
+#define AUX_I2C_WRITE_SUCCESS 0x1
+#define AUX_I2C_WRITE_PARTIAL_SUCCESS 0x2
+
+#define EQ_MAX_RETRY 5
