On Fri, Nov 01, 2024 at 06:50:25PM +0800, Yongbang Shi wrote:
From: baihan li <libai...@huawei.com>

Add dp aux read/write functions. They are basic functions
and will be used later.

Signed-off-by: baihan li <libai...@huawei.com>
Signed-off-by: yongbang shi <shiyongb...@huawei.com>
Is this a proper capitalization of your names? Usually the first letter
of each of them is capital.

---
ChangeLog:
v2 -> v3:
   - put the macro definations in latter patch where they are actually used, 
suggested by Dmitry Baryshkov.
   - rename some macro definations to make them sensible, suggested by Dmitry 
Baryshkov.
   - using FIELD_PREP and FIELD_GET, suggested by Dmitry Baryshkov.
   - using DP_DPCD_REV_foo, suggested by Dmitry Baryshkov.
   - fix build errors reported by kernel test robot <l...@intel.com>
     Closes: 
https://lore.kernel.org/oe-kbuild-all/202410250305.uhkdhtxy-...@intel.com/
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-shiyongb...@huawei.com/
---
  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   |  23 +++
  drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h  |  58 +++++++
  .../gpu/drm/hisilicon/hibmc/dp/dp_config.h    |  19 ++
  drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h   |  27 +++
  6 files changed, 291 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_config.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..49ecda672109
--- /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 hibmc_dp_aux_reset(const struct dp_dev *dp)
+{
+       dp_reg_write_field(dp->base + DP_DPTX_RST_CTRL, DP_CFG_AUX_RST_N, 0x0);
+       usleep_range(10, 15);
+       dp_reg_write_field(dp->base + DP_DPTX_RST_CTRL, DP_CFG_AUX_RST_N, 0x1);
+}
+
+static void hibmc_dp_aux_read_data(struct dp_dev *dp, u8 *buf, u8 size)
+{
+       u32 reg_num;
+       u32 value;
+       u32 num;
+       u8 i, j;
+
+       reg_num = DIV_ROUND_UP(size, BYTES_IN_U32);
+       for (i = 0; i < reg_num; i++) {
+               /* number of bytes read from a single register */
+               num = min(size - i * BYTES_IN_U32, BYTES_IN_U32);
+               value = readl(dp->base + DP_AUX_RD_DATA0 + i * BYTES_IN_U32);
+               /* convert the 32-bit value of the register to the buffer. */
+               for (j = 0; j < num; j++)
+                       buf[i * BYTES_IN_U32 + j] = value >> (j * BITS_IN_U8);
put_unaligned_le32()

+       }
+}
+
+static void hibmc_dp_aux_write_data(struct dp_dev *dp, u8 *buf, u8 size)
+{
+       u32 reg_num;
+       u32 value;
+       u8 i, j;
+       u32 num;
+
+       reg_num = DIV_ROUND_UP(size, BYTES_IN_U32);
+       for (i = 0; i < reg_num; i++) {
+               /* number of bytes written to a single register */
+               num = min_t(u8, size - i * BYTES_IN_U32, BYTES_IN_U32);
+               value = 0;
+               /* obtain the 32-bit value written to a single register. */
+               for (j = 0; j < num; j++)
+                       value |= buf[i * BYTES_IN_U32 + j] << (j * BITS_IN_U8);
get_unaligned_le32()

Hi Dimitry,
Thanks for your advice. I try to use these foo_unaligned_le32(), however, 
here's the situation.
The buffer I put in aux write or read functions are not always 4bytes or 4-byte 
alignment,
so when I need to process 1 byte or 2 bytes data, I need to use 
put_unaligned_le16 or
put_unaligned_le8  with if-statement, it's kind of complicated. So I think it's 
fine
to keep these implementation here.
Thanks,
Baihan


+               /* writing data to a single register */
+               writel(value, dp->base + DP_AUX_WR_DATA0 + i * BYTES_IN_U32);
+       }
+}
+
+static u32 hibmc_dp_aux_build_cmd(const struct drm_dp_aux_msg *msg)
+{
+       u32 aux_cmd = msg->request;
+
+       if (msg->size)
+               aux_cmd |= FIELD_PREP(AUX_CMD_REQ_LEN, (msg->size - 1));
+       else
+               aux_cmd |= FIELD_PREP(AUX_CMD_I2C_ADDR_ONLY, 1);
+
+       aux_cmd |= FIELD_PREP(AUX_CMD_ADDR, msg->address);
+
+       return aux_cmd;
+}
+
+/* ret >= 0 ,ret is size; ret < 0, ret is err code */
+static int hibmc_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;
Should this be an error instead?

+
+       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);
Replace all ret= with returns. Nothing happens after the switch-case, so
return right away.

+               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 */
Nit: only a part of data wass read successfully.
move the comment into the underlying `

+               if (buf_data_cnt != msg->size) {
+                       ret = -EBUSY;
+               } else { /* all data is successfully read */
+                       hibmc_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 hibmc_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);
+
+       hibmc_dp_aux_write_data(dp, msg->buffer, msg->size);
+
+       aux_cmd = hibmc_dp_aux_build_cmd(msg);
+       writel(aux_cmd, dp->base + DP_AUX_CMD_ADDR);
+
+       /* enable aux transfer */
+       dp_reg_write_field(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) {
+               hibmc_dp_aux_reset(dp);
+               return ret;
+       }
+
+       return hibmc_dp_aux_parse_xfer(dp, msg);
+}
+
+void hibmc_dp_aux_init(struct dp_dev *dp)
+{
+       dp_reg_write_field(dp->base + DP_AUX_REQ, DP_CFG_AUX_SYNC_LEN_SEL, 0x0);
+       dp_reg_write_field(dp->base + DP_AUX_REQ, DP_CFG_AUX_TIMER_TIMEOUT, 
0x1);
+       dp_reg_write_field(dp->base + DP_AUX_REQ, DP_CFG_AUX_MIN_PULSE_NUM, 
DP_MIN_PULSE_NUM);
+
+       dp->aux.transfer = hibmc_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..794bb0482ea7
--- /dev/null
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.h
@@ -0,0 +1,23 @@
+/* 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
Move to the source file

+#define AUX_I2C_WRITE_PARTIAL_SUCCESS  0x2
Ditto

+#define EQ_MAX_RETRY                   5
Unused

+#define BYTES_IN_U32                   4

+#define BITS_IN_U8                     8
This one will go away after using foo_unaligned_le32

+
+/* aux_cmd_addr register shift */
+#define AUX_CMD_REQ_LEN                        GENMASK(7, 4)
+#define AUX_CMD_ADDR                   GENMASK(27, 8)
+#define AUX_CMD_I2C_ADDR_ONLY          BIT(28)
These can go to the source file too. Or to dp_reg.h. Don't spawn that
all over the place.

+
+void hibmc_dp_aux_init(struct dp_dev *dp);
As the header becomes nearly empty, merge the remnants to a generic
header.

+
+#endif
diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h 
b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h
new file mode 100644
index 000000000000..61a59fd59962
--- /dev/null
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (c) 2024 Hisilicon Limited. */
+
+#ifndef DP_COMM_H
+#define DP_COMM_H
+
+#include <linux/types.h>
+#include <linux/bitops.h>
+#include <linux/errno.h>
+#include <linux/mutex.h>
+#include <linux/kernel.h>
+#include <linux/bitfield.h>
+#include <linux/io.h>
+
+#include <drm/display/drm_dp_helper.h>
+
+#define dp_reg_read_field(addr, mask)                          \
These are still using dp_ prefix. Also using static inline functions
might be easier to handle.

+               FIELD_GET(mask, readl(addr))
+
+#define dp_field_modify(reg_value, mask, value) ({             \
+               (reg_value) &= ~(mask);                             \
+               (reg_value) |= FIELD_PREP(mask, value); })
+
+#define dp_reg_write_field(addr, mask, val) ({                 \
+               typeof(addr) _addr = (addr);                    \
+               u32 _value = readl(_addr);                      \
+               dp_field_modify(_value, mask, val);             \
+               writel(_value, _addr); })
I'm still very unsatisfied here. You have an RMW code with no locking.
If anything writes to the same location at the same time, the driver is
busted.

+
+struct link_status {
It is hibmc-specific, so please prefix accordingly.

+       bool clock_recovered;
+       bool channel_equalized;
+       u8 cr_done_lanes;
+};
+
+struct link_cap {
+       int rx_dpcd_revision;
+       u8 link_rate;
+       u8 lanes;
+       bool is_tps3;
+       bool is_tps4;
+};
+
+struct hibmc_dp_link {
+       struct link_status status;
+       u8 *train_set;
+       struct link_cap cap;
+};
Please don't define the structures/fields that are not used by the
patch. Introduce them when required.

+
+struct dp_dev {
+       struct hibmc_dp_link link;
+       struct drm_dp_aux aux;
+       struct drm_device *dev;
+       void __iomem *base;
+       u8 dpcd[DP_RECEIVER_CAP_SIZE];
+};
+
+#endif
diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_config.h 
b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_config.h
new file mode 100644
index 000000000000..0b965e6ba7b3
--- /dev/null
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_config.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (c) 2024 Hisilicon Limited. */
+
+#ifndef DP_CONFIG_H
+#define DP_CONFIG_H
+
+#define DP_BPP                 24
+#define DP_SYMBOL_PER_FCLK     4
+#define DP_MSA1                        0x20
+#define DP_MSA2                        0x845c00
+#define DP_OFFSET              0x1e0000
+#define DP_HDCP                        0x2
+#define DP_INT_RST             0xffff
+#define DP_DPTX_RST            0x3ff
+#define DP_CLK_EN              0x7
+#define DP_SYNC_EN_MASK                0x3
+#define DP_LINK_RATE_CAL       27
+
+#endif
diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h 
b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h
new file mode 100644
index 000000000000..83cf0cc06ae2
--- /dev/null
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (c) 2024 Hisilicon Limited. */
+
+#ifndef DP_REG_H
+#define DP_REG_H
+
+#define DP_AUX_CMD_ADDR                        0x50
+#define DP_AUX_WR_DATA0                        0x54
+#define DP_AUX_WR_DATA1                        0x58
+#define DP_AUX_WR_DATA2                        0x5c
+#define DP_AUX_WR_DATA3                        0x60
+#define DP_AUX_RD_DATA0                        0x64
+#define DP_AUX_REQ                     0x74
+#define DP_AUX_STATUS                  0x78
+#define DP_DPTX_RST_CTRL               0x700
+
+#define DP_CFG_AUX_SYNC_LEN_SEL                        BIT(1)
+#define DP_CFG_AUX_TIMER_TIMEOUT               BIT(2)
+#define DP_CFG_AUX_MIN_PULSE_NUM               GENMASK(13, 9)
+#define DP_CFG_AUX_REQ                         BIT(0)
+#define DP_CFG_AUX_RST_N                       BIT(4)
+#define DP_CFG_AUX_TIMEOUT                     BIT(0)
+#define DP_CFG_AUX_READY_DATA_BYTE             GENMASK(16, 12)
+#define DP_CFG_AUX                             GENMASK(24, 17)
+#define DP_CFG_AUX_STATUS                      GENMASK(11, 4)
+
+#endif
--
2.33.0

Reply via email to