Re: [PATCH v12 01/11] media: staging: phy-rockchip-dphy: add Rockchip MIPI Synopsys DPHY driver

From: Laurent Pinchart
Date: Mon Jan 06 2020 - 20:12:01 EST


Hi Helen and Ezequiel,

Thank you for the patch.

On Fri, Dec 27, 2019 at 05:01:06PM -0300, Helen Koike wrote:
> From: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
>
> Add driver for Rockchip MIPI Synopsys DPHY driver
>
> Signed-off-by: Tomasz Figa <tfiga@xxxxxxxxxxxx>
> Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
> Signed-off-by: Helen Koike <helen.koike@xxxxxxxxxxxxx>
>
> ---
>
> Changes in v12:
> - several cleanups
> - remove "rx" from function names, as this driver only supports rx
>
> Changes in v11:
> - fix checkpatch errors
>
> Changes in v10: None
> Changes in v9:
> - Move to staging
> - replace memcpy by a directly assignment
> - remove unecessary ret variable in rockchip_dphy_init
> - s/0x1/1
> - s/0x0/0
> - coding style changes
> - dphy_reg variable sizes
> - variables from int to unsigned int
> - rename functions to start with rk_
> - rename dphy0 to rx
> - fix hardcoded lane0 usage
> - disable rx on power off
> - general cleanups of unused variables
>
> Changes in v8:
> - Remove boiler plate license text
>
> Changes in v7:
> - Migrate dphy specific code from
> drivers/media/platform/rockchip/isp1/mipi_dphy_sy.c
> to drivers/phy/rockchip/phy-rockchip-dphy.c
> - Drop support for rk3288
> - Drop support for dphy txrx
> - code styling and checkpatch fixes
>
> drivers/staging/media/Kconfig | 2 +
> drivers/staging/media/Makefile | 1 +
> .../staging/media/phy-rockchip-dphy/Kconfig | 11 +
> .../staging/media/phy-rockchip-dphy/Makefile | 2 +
> drivers/staging/media/phy-rockchip-dphy/TODO | 6 +
> .../phy-rockchip-dphy/phy-rockchip-dphy.c | 396 ++++++++++++++++++
> 6 files changed, 418 insertions(+)
> create mode 100644 drivers/staging/media/phy-rockchip-dphy/Kconfig
> create mode 100644 drivers/staging/media/phy-rockchip-dphy/Makefile
> create mode 100644 drivers/staging/media/phy-rockchip-dphy/TODO
> create mode 100644 drivers/staging/media/phy-rockchip-dphy/phy-rockchip-dphy.c
>
> diff --git a/drivers/staging/media/Kconfig b/drivers/staging/media/Kconfig
> index 642adc4c24d2..a47484473883 100644
> --- a/drivers/staging/media/Kconfig
> +++ b/drivers/staging/media/Kconfig
> @@ -38,4 +38,6 @@ source "drivers/staging/media/ipu3/Kconfig"
>
> source "drivers/staging/media/soc_camera/Kconfig"
>
> +source "drivers/staging/media/phy-rockchip-dphy/Kconfig"
> +
> endif
> diff --git a/drivers/staging/media/Makefile b/drivers/staging/media/Makefile
> index 2f1711a8aeed..b0eae3906208 100644
> --- a/drivers/staging/media/Makefile
> +++ b/drivers/staging/media/Makefile
> @@ -8,3 +8,4 @@ obj-$(CONFIG_TEGRA_VDE) += tegra-vde/
> obj-$(CONFIG_VIDEO_HANTRO) += hantro/
> obj-$(CONFIG_VIDEO_IPU3_IMGU) += ipu3/
> obj-$(CONFIG_SOC_CAMERA) += soc_camera/
> +obj-$(CONFIG_PHY_ROCKCHIP_DPHY) += phy-rockchip-dphy/
> diff --git a/drivers/staging/media/phy-rockchip-dphy/Kconfig b/drivers/staging/media/phy-rockchip-dphy/Kconfig
> new file mode 100644
> index 000000000000..7378bd75fa7c
> --- /dev/null
> +++ b/drivers/staging/media/phy-rockchip-dphy/Kconfig
> @@ -0,0 +1,11 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +#
> +# Phy drivers for Rockchip platforms

s/Phy/MIPI D-PHY/

> +#
> +config PHY_ROCKCHIP_DPHY
> + tristate "Rockchip MIPI Synopsys DPHY driver"
> + depends on (ARCH_ROCKCHIP || COMPILE_TEST) && OF
> + select GENERIC_PHY_MIPI_DPHY
> + select GENERIC_PHY
> + help
> + Enable this to support the Rockchip MIPI Synopsys DPHY.
> diff --git a/drivers/staging/media/phy-rockchip-dphy/Makefile b/drivers/staging/media/phy-rockchip-dphy/Makefile
> new file mode 100644
> index 000000000000..24679dc950cd
> --- /dev/null
> +++ b/drivers/staging/media/phy-rockchip-dphy/Makefile
> @@ -0,0 +1,2 @@
> +# SPDX-License-Identifier: GPL-2.0
> +obj-$(CONFIG_PHY_ROCKCHIP_DPHY) += phy-rockchip-dphy.o
> diff --git a/drivers/staging/media/phy-rockchip-dphy/TODO b/drivers/staging/media/phy-rockchip-dphy/TODO
> new file mode 100644
> index 000000000000..e1fda55babef
> --- /dev/null
> +++ b/drivers/staging/media/phy-rockchip-dphy/TODO
> @@ -0,0 +1,6 @@
> +The major reason for keeping this in staging is because the only driver

s/major/main/

> +who uses this is rkisp1 who is also in staging. It should be moved together

s/who uses this/that uses this/
s/who is also/, which is also/

> +rkisp1.

s/rkisp1/with rkisp1/ ?

> +
> +Please CC patches to Linux Media <linux-media@xxxxxxxxxxxxxxx> and
> +Helen Koike <helen.koike@xxxxxxxxxxxxx>.
> diff --git a/drivers/staging/media/phy-rockchip-dphy/phy-rockchip-dphy.c b/drivers/staging/media/phy-rockchip-dphy/phy-rockchip-dphy.c
> new file mode 100644
> index 000000000000..c3fe9c64b45f
> --- /dev/null
> +++ b/drivers/staging/media/phy-rockchip-dphy/phy-rockchip-dphy.c
> @@ -0,0 +1,396 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)

Any reason for this ? Kernel code is usually GPL-2.0.

> +/*
> + * Rockchip MIPI Synopsys DPHY driver
> + *
> + * Copyright (C) 2019 Collabora, Ltd.
> + *
> + * Based on:
> + *
> + * drivers/media/platform/rockchip/isp1/mipi_dphy_sy.c
> + * in https://chromium.googlesource.com/chromiumos/third_party/kernel,
> + * chromeos-4.4 branch.
> + *
> + * Copyright (C) 2017 Fuzhou Rockchip Electronics Co., Ltd.
> + * Jacob Chen <jacob2.chen@xxxxxxxxxxxxxx>
> + * Shunqian Zheng <zhengsq@xxxxxxxxxxxxxx>
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/io.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/phy/phy.h>
> +#include <linux/phy/phy-mipi-dphy.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +#define RK3399_GRF_SOC_CON9 0x6224
> +#define RK3399_GRF_SOC_CON21 0x6254
> +#define RK3399_GRF_SOC_CON22 0x6258
> +#define RK3399_GRF_SOC_CON23 0x625c
> +#define RK3399_GRF_SOC_CON24 0x6260
> +#define RK3399_GRF_SOC_CON25 0x6264
> +#define RK3399_GRF_SOC_STATUS1 0xe2a4
> +
> +#define CLOCK_LANE_HS_RX_CONTROL 0x34
> +#define LANE0_HS_RX_CONTROL 0x44
> +#define LANE1_HS_RX_CONTROL 0x54
> +#define LANE2_HS_RX_CONTROL 0x84
> +#define LANE3_HS_RX_CONTROL 0x94
> +#define LANES_THS_SETTLE_CONTROL 0x75
> +#define THS_SETTLE_COUNTER_THRESHOLD 0x04
> +
> +struct hsfreq_range {
> + u16 range_h;
> + u8 cfg_bit;
> +};
> +
> +static const struct hsfreq_range rk3399_mipidphy_hsfreq_ranges[] = {
> + { 89, 0x00 }, { 99, 0x10 }, { 109, 0x20 }, { 129, 0x01 },
> + { 139, 0x11 }, { 149, 0x21 }, { 169, 0x02 }, { 179, 0x12 },
> + { 199, 0x22 }, { 219, 0x03 }, { 239, 0x13 }, { 249, 0x23 },
> + { 269, 0x04 }, { 299, 0x14 }, { 329, 0x05 }, { 359, 0x15 },
> + { 399, 0x25 }, { 449, 0x06 }, { 499, 0x16 }, { 549, 0x07 },
> + { 599, 0x17 }, { 649, 0x08 }, { 699, 0x18 }, { 749, 0x09 },
> + { 799, 0x19 }, { 849, 0x29 }, { 899, 0x39 }, { 949, 0x0a },
> + { 999, 0x1a }, { 1049, 0x2a }, { 1099, 0x3a }, { 1149, 0x0b },
> + { 1199, 0x1b }, { 1249, 0x2b }, { 1299, 0x3b }, { 1349, 0x0c },
> + { 1399, 0x1c }, { 1449, 0x2c }, { 1500, 0x3c }
> +};
> +
> +static const char * const rk3399_mipidphy_clks[] = {
> + "dphy-ref",
> + "dphy-cfg",
> + "grf",
> +};
> +
> +enum dphy_reg_id {
> + GRF_DPHY_RX0_TURNDISABLE = 0,
> + GRF_DPHY_RX0_FORCERXMODE,
> + GRF_DPHY_RX0_FORCETXSTOPMODE,
> + GRF_DPHY_RX0_ENABLE,
> + GRF_DPHY_RX0_TESTCLR,
> + GRF_DPHY_RX0_TESTCLK,
> + GRF_DPHY_RX0_TESTEN,
> + GRF_DPHY_RX0_TESTDIN,
> + GRF_DPHY_RX0_TURNREQUEST,
> + GRF_DPHY_RX0_TESTDOUT,
> + GRF_DPHY_TX0_TURNDISABLE,
> + GRF_DPHY_TX0_FORCERXMODE,
> + GRF_DPHY_TX0_FORCETXSTOPMODE,
> + GRF_DPHY_TX0_TURNREQUEST,
> + GRF_DPHY_TX1RX1_TURNDISABLE,
> + GRF_DPHY_TX1RX1_FORCERXMODE,
> + GRF_DPHY_TX1RX1_FORCETXSTOPMODE,
> + GRF_DPHY_TX1RX1_ENABLE,
> + GRF_DPHY_TX1RX1_MASTERSLAVEZ,
> + GRF_DPHY_TX1RX1_BASEDIR,
> + GRF_DPHY_TX1RX1_ENABLECLK,
> + GRF_DPHY_TX1RX1_TURNREQUEST,
> + GRF_DPHY_RX1_SRC_SEL,
> + /* rk3288 only */
> + GRF_CON_DISABLE_ISP,
> + GRF_CON_ISP_DPHY_SEL,
> + GRF_DSI_CSI_TESTBUS_SEL,
> + GRF_DVP_V18SEL,
> + /* below is for rk3399 only */
> + GRF_DPHY_RX0_CLK_INV_SEL,
> + GRF_DPHY_RX1_CLK_INV_SEL,
> +};
> +
> +struct dphy_reg {
> + u16 offset;
> + u8 mask;
> + u8 shift;
> +};
> +
> +#define PHY_REG(_offset, _width, _shift) \
> + { .offset = _offset, .mask = BIT(_width) - 1, .shift = _shift, }
> +
> +static const struct dphy_reg rk3399_grf_dphy_regs[] = {
> + [GRF_DPHY_RX0_TURNREQUEST] = PHY_REG(RK3399_GRF_SOC_CON9, 4, 0),
> + [GRF_DPHY_RX0_CLK_INV_SEL] = PHY_REG(RK3399_GRF_SOC_CON9, 1, 10),
> + [GRF_DPHY_RX1_CLK_INV_SEL] = PHY_REG(RK3399_GRF_SOC_CON9, 1, 11),
> + [GRF_DPHY_RX0_ENABLE] = PHY_REG(RK3399_GRF_SOC_CON21, 4, 0),
> + [GRF_DPHY_RX0_FORCERXMODE] = PHY_REG(RK3399_GRF_SOC_CON21, 4, 4),
> + [GRF_DPHY_RX0_FORCETXSTOPMODE] = PHY_REG(RK3399_GRF_SOC_CON21, 4, 8),
> + [GRF_DPHY_RX0_TURNDISABLE] = PHY_REG(RK3399_GRF_SOC_CON21, 4, 12),
> + [GRF_DPHY_TX0_FORCERXMODE] = PHY_REG(RK3399_GRF_SOC_CON22, 4, 0),
> + [GRF_DPHY_TX0_FORCETXSTOPMODE] = PHY_REG(RK3399_GRF_SOC_CON22, 4, 4),
> + [GRF_DPHY_TX0_TURNDISABLE] = PHY_REG(RK3399_GRF_SOC_CON22, 4, 8),
> + [GRF_DPHY_TX0_TURNREQUEST] = PHY_REG(RK3399_GRF_SOC_CON22, 4, 12),
> + [GRF_DPHY_TX1RX1_ENABLE] = PHY_REG(RK3399_GRF_SOC_CON23, 4, 0),
> + [GRF_DPHY_TX1RX1_FORCERXMODE] = PHY_REG(RK3399_GRF_SOC_CON23, 4, 4),
> + [GRF_DPHY_TX1RX1_FORCETXSTOPMODE] = PHY_REG(RK3399_GRF_SOC_CON23, 4, 8),
> + [GRF_DPHY_TX1RX1_TURNDISABLE] = PHY_REG(RK3399_GRF_SOC_CON23, 4, 12),
> + [GRF_DPHY_TX1RX1_TURNREQUEST] = PHY_REG(RK3399_GRF_SOC_CON24, 4, 0),
> + [GRF_DPHY_RX1_SRC_SEL] = PHY_REG(RK3399_GRF_SOC_CON24, 1, 4),
> + [GRF_DPHY_TX1RX1_BASEDIR] = PHY_REG(RK3399_GRF_SOC_CON24, 1, 5),
> + [GRF_DPHY_TX1RX1_ENABLECLK] = PHY_REG(RK3399_GRF_SOC_CON24, 1, 6),
> + [GRF_DPHY_TX1RX1_MASTERSLAVEZ] = PHY_REG(RK3399_GRF_SOC_CON24, 1, 7),
> + [GRF_DPHY_RX0_TESTDIN] = PHY_REG(RK3399_GRF_SOC_CON25, 8, 0),
> + [GRF_DPHY_RX0_TESTEN] = PHY_REG(RK3399_GRF_SOC_CON25, 1, 8),
> + [GRF_DPHY_RX0_TESTCLK] = PHY_REG(RK3399_GRF_SOC_CON25, 1, 9),
> + [GRF_DPHY_RX0_TESTCLR] = PHY_REG(RK3399_GRF_SOC_CON25, 1, 10),
> + [GRF_DPHY_RX0_TESTDOUT] = PHY_REG(RK3399_GRF_SOC_STATUS1, 8, 0),
> +};
> +
> +struct rk_dphy_drv_data {
> + const char * const *clks;
> + unsigned int num_clks;
> + const struct hsfreq_range *hsfreq_ranges;
> + unsigned int num_hsfreq_ranges;
> + const struct dphy_reg *regs;
> +};
> +
> +struct rk_dphy {
> + struct device *dev;
> + struct regmap *grf;
> + struct clk_bulk_data *clks;
> +
> + const struct rk_dphy_drv_data *drv_data;
> + struct phy_configure_opts_mipi_dphy config;
> +
> + u8 hsfreq;
> +};
> +
> +static inline void rk_dphy_write_grf(struct rk_dphy *priv,
> + unsigned int index, u8 value)
> +{
> + const struct dphy_reg *reg = &priv->drv_data->regs[index];
> + /* Update high word */
> + unsigned int val = (value << reg->shift) |
> + (reg->mask << (reg->shift + 16));
> +
> + WARN_ON(!reg->offset);

Maybe

if (WARN_ON(!reg->offset))
return;

> + regmap_write(priv->grf, reg->offset, val);
> +}
> +
> +static void rk_dphy_write(struct rk_dphy *priv,
> + u8 test_code, u8 test_data)
> +{
> + /*
> + * With the falling edge on TESTCLK, the TESTDIN[7:0] signal content
> + * is latched internally as the current test code. Test data is
> + * programmed internally by rising edge on TESTCLK.
> + */
> + rk_dphy_write_grf(priv, GRF_DPHY_RX0_TESTCLK, 1);

Do we need this first line, as the function always exits with TESTCLK=1,
and TESTCLK is initialized to 1 before calling rk_dphy_write for the
first time ?

> + rk_dphy_write_grf(priv, GRF_DPHY_RX0_TESTDIN, test_code);
> + rk_dphy_write_grf(priv, GRF_DPHY_RX0_TESTEN, 1);
> + rk_dphy_write_grf(priv, GRF_DPHY_RX0_TESTCLK, 0);
> + rk_dphy_write_grf(priv, GRF_DPHY_RX0_TESTEN, 0);
> + rk_dphy_write_grf(priv, GRF_DPHY_RX0_TESTDIN, test_data);
> + rk_dphy_write_grf(priv, GRF_DPHY_RX0_TESTCLK, 1);
> +}
> +
> +static void rk_dphy_enable(struct rk_dphy *priv)
> +{
> + rk_dphy_write_grf(priv, GRF_DPHY_RX0_FORCERXMODE, 0);
> + rk_dphy_write_grf(priv, GRF_DPHY_RX0_FORCETXSTOPMODE, 0);
> +
> + /* Disable lane turn around, which is ignored in receive mode */
> + rk_dphy_write_grf(priv, GRF_DPHY_RX0_TURNREQUEST, 0);
> + rk_dphy_write_grf(priv, GRF_DPHY_RX0_TURNDISABLE, 0xf);
> +
> + rk_dphy_write_grf(priv, GRF_DPHY_RX0_ENABLE,
> + GENMASK(priv->config.lanes - 1, 0));
> +
> + /* dphy start */
> + rk_dphy_write_grf(priv, GRF_DPHY_RX0_TESTCLK, 1);
> + rk_dphy_write_grf(priv, GRF_DPHY_RX0_TESTCLR, 1);
> + usleep_range(100, 150);
> + rk_dphy_write_grf(priv, GRF_DPHY_RX0_TESTCLR, 0);
> + usleep_range(100, 150);
> +
> + /* set clock lane */
> + /* HS hsfreq_range & lane 0 settle bypass */
> + rk_dphy_write(priv, CLOCK_LANE_HS_RX_CONTROL, 0);
> + /* HS RX Control of lane0 */
> + rk_dphy_write(priv, LANE0_HS_RX_CONTROL, priv->hsfreq << 1);
> + /* HS RX Control of lane1 */
> + rk_dphy_write(priv, LANE1_HS_RX_CONTROL, priv->hsfreq << 1);
> + /* HS RX Control of lane2 */
> + rk_dphy_write(priv, LANE2_HS_RX_CONTROL, priv->hsfreq << 1);
> + /* HS RX Control of lane3 */
> + rk_dphy_write(priv, LANE3_HS_RX_CONTROL, priv->hsfreq << 1);
> + /* HS RX Data Lanes Settle State Time Control */
> + rk_dphy_write(priv, LANES_THS_SETTLE_CONTROL,
> + THS_SETTLE_COUNTER_THRESHOLD);
> +
> + /* Normal operation */
> + rk_dphy_write(priv, 0x0, 0);
> +}
> +
> +static int rk_dphy_configure(struct phy *phy, union phy_configure_opts *opts)
> +{
> + struct rk_dphy *priv = phy_get_drvdata(phy);
> + const struct rk_dphy_drv_data *drv_data = priv->drv_data;
> + struct phy_configure_opts_mipi_dphy *config = &opts->mipi_dphy;
> + unsigned int i, hsfreq = 0, data_rate_mbps = config->hs_clk_rate;

Maybe one variable per line ?

> + int ret;
> +
> + /* pass with phy_mipi_dphy_get_default_config (with pixel rate?) */
> + ret = phy_mipi_dphy_config_validate(config);
> + if (ret)
> + return ret;

I would add a blank line here.

> + do_div(data_rate_mbps, 1000 * 1000);

data_rate_mbps is an unsigned int, so you can use

data_rate_mbps /= 1000 * 1000;

However, you're potentially truncating hs_clk_rate by assigning it to
data_rate_mbps, so I would remove the assignment at declaration time and
do

data_rate_mbps = div_u64(config->hs_clk_rate, 1000 * 1000);

or define data_rate_mbps as an unsigned long.

> +
> + dev_dbg(priv->dev, "lanes %d - data_rate_mbps %u\n",
> + config->lanes, data_rate_mbps);
> + for (i = 0; i < drv_data->num_hsfreq_ranges; i++) {
> + if (drv_data->hsfreq_ranges[i].range_h >= data_rate_mbps) {
> + hsfreq = drv_data->hsfreq_ranges[i].cfg_bit;
> + break;
> + }
> + }
> + if (!hsfreq)
> + return -EINVAL;
> +
> + priv->hsfreq = hsfreq;
> + priv->config = *config;
> + return 0;
> +}
> +
> +static int rk_dphy_power_on(struct phy *phy)
> +{
> + struct rk_dphy *priv = phy_get_drvdata(phy);
> + int ret;
> +
> + ret = clk_bulk_enable(priv->drv_data->num_clks, priv->clks);
> + if (ret)
> + return ret;
> +
> + rk_dphy_enable(priv);
> +
> + return 0;
> +}
> +
> +static int rk_dphy_power_off(struct phy *phy)
> +{
> + struct rk_dphy *priv = phy_get_drvdata(phy);
> +
> + rk_dphy_write_grf(priv, GRF_DPHY_RX0_ENABLE, 0);
> + clk_bulk_disable(priv->drv_data->num_clks, priv->clks);
> + return 0;
> +}
> +
> +static int rk_dphy_init(struct phy *phy)
> +{
> + struct rk_dphy *priv = phy_get_drvdata(phy);
> +
> + return clk_bulk_prepare(priv->drv_data->num_clks, priv->clks);
> +}
> +
> +static int rk_dphy_exit(struct phy *phy)
> +{
> + struct rk_dphy *priv = phy_get_drvdata(phy);
> +
> + clk_bulk_unprepare(priv->drv_data->num_clks, priv->clks);
> + return 0;
> +}
> +
> +static const struct phy_ops rk_dphy_ops = {
> + .power_on = rk_dphy_power_on,
> + .power_off = rk_dphy_power_off,
> + .init = rk_dphy_init,
> + .exit = rk_dphy_exit,
> + .configure = rk_dphy_configure,
> + .owner = THIS_MODULE,
> +};
> +
> +static const struct rk_dphy_drv_data rk3399_mipidphy_drv_data = {
> + .clks = rk3399_mipidphy_clks,
> + .num_clks = ARRAY_SIZE(rk3399_mipidphy_clks),
> + .hsfreq_ranges = rk3399_mipidphy_hsfreq_ranges,
> + .num_hsfreq_ranges = ARRAY_SIZE(rk3399_mipidphy_hsfreq_ranges),
> + .regs = rk3399_grf_dphy_regs,
> +};
> +
> +static const struct of_device_id rk_dphy_dt_ids[] = {
> + {
> + .compatible = "rockchip,rk3399-mipi-dphy",
> + .data = &rk3399_mipidphy_drv_data,
> + },
> + {}
> +};
> +MODULE_DEVICE_TABLE(of, rk_dphy_dt_ids);
> +
> +static int rk_dphy_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct device_node *np = dev->of_node;
> + const struct rk_dphy_drv_data *drv_data;
> + struct phy_provider *phy_provider;
> + const struct of_device_id *of_id;
> + struct rk_dphy *priv;
> + struct regmap *grf;
> + struct phy *phy;
> + unsigned int i;
> + int ret;
> +
> + if (!dev->parent || !dev->parent->of_node)
> + return -ENODEV;
> +
> + if (platform_get_resource(pdev, IORESOURCE_MEM, 0)) {
> + dev_err(dev, "Rockchip DPHY driver only suports RX mode\n");
> + return -EINVAL;
> + }
> +
> + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> + priv->dev = dev;
> +
> + grf = syscon_node_to_regmap(dev->parent->of_node);
> + if (IS_ERR(grf)) {
> + grf = syscon_regmap_lookup_by_phandle(dev->of_node,
> + "rockchip,grf");

Is this for backward compatibility with older bindings ? Do we still
need it ? If so I would add a comment to explain why.

With the above small issues fixed,

Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

> + if (IS_ERR(grf)) {
> + dev_err(dev, "Can't find GRF syscon\n");
> + return -ENODEV;
> + }
> + }
> + priv->grf = grf;
> +
> + of_id = of_match_device(rk_dphy_dt_ids, dev);
> + if (!of_id)
> + return -EINVAL;
> +
> + drv_data = of_id->data;
> + priv->drv_data = drv_data;
> + priv->clks = devm_kcalloc(&pdev->dev, drv_data->num_clks,
> + sizeof(*priv->clks), GFP_KERNEL);
> + if (!priv->clks)
> + return -ENOMEM;
> + for (i = 0; i < drv_data->num_clks; i++)
> + priv->clks[i].id = drv_data->clks[i];
> + ret = devm_clk_bulk_get(&pdev->dev, drv_data->num_clks, priv->clks);
> + if (ret)
> + return ret;
> +
> + phy = devm_phy_create(dev, np, &rk_dphy_ops);
> + if (IS_ERR(phy)) {
> + dev_err(dev, "failed to create phy\n");
> + return PTR_ERR(phy);
> + }
> + phy_set_drvdata(phy, priv);
> +
> + phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
> +
> + return PTR_ERR_OR_ZERO(phy_provider);
> +}
> +
> +static struct platform_driver rk_dphy_driver = {
> + .probe = rk_dphy_probe,
> + .driver = {
> + .name = "rockchip-mipi-dphy",
> + .of_match_table = rk_dphy_dt_ids,
> + },
> +};
> +module_platform_driver(rk_dphy_driver);
> +
> +MODULE_AUTHOR("Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Rockchip MIPI Synopsys DPHY driver");
> +MODULE_LICENSE("Dual MIT/GPL");

--
Regards,

Laurent Pinchart