[PATCH V3 drm-dp 1/4] drm/hisilicon/hibmc: add dp aux in hibmc
Yongbang Shi
shiyongbang at huawei.com
Wed Nov 13 03:17:38 UTC 2024
> On Fri, Nov 01, 2024 at 06:50:25PM +0800, Yongbang Shi wrote:
>> From: baihan li <libaihan at huawei.com>
>>
>> Add dp aux read/write functions. They are basic functions
>> and will be used later.
>>
>> Signed-off-by: baihan li <libaihan at huawei.com>
>> Signed-off-by: yongbang shi <shiyongbang at 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 <lkp at intel.com>
>> Closes: https://lore.kernel.org/oe-kbuild-all/202410250305.UHKDhtxy-lkp@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-shiyongbang@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
>>
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