Re: [PATCH v8 04/14] media: rkisp1: add Rockchip MIPI Synopsys DPHY driver

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Helen,

On Wed, Aug 21, 2019 at 06:46:15PM -0300, Helen Koike wrote:
> On 8/15/19 2:54 PM, Laurent Pinchart wrote:
> > On Wed, Aug 07, 2019 at 10:37:55AM -0300, Helen Koike wrote:
> >> On 8/7/19 10:05 AM, Sakari Ailus wrote:
> >>> On Tue, Jul 30, 2019 at 03:42:46PM -0300, Helen Koike wrote:
> >>>> From: Jacob Chen <jacob2.chen@rock-chips.com>
> >>>>
> >>>> This commit adds a subdev driver for Rockchip MIPI Synopsys DPHY driver
> >>>>
> >>>> Signed-off-by: Jacob Chen <jacob2.chen@rock-chips.com>
> >>>> Signed-off-by: Shunqian Zheng <zhengsq@rock-chips.com>
> >>>> Signed-off-by: Tomasz Figa <tfiga@chromium.org>
> >>>> [migrate to phy framework]
> >>>> Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
> >>>> [update for upstream]
> >>>> Signed-off-by: Helen Koike <helen.koike@collabora.com>
> >>>>
> >>>> ---
> >>>>
> >>>> 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/phy/rockchip/Kconfig             |   8 +
> >>>>  drivers/phy/rockchip/Makefile            |   1 +
> >>>>  drivers/phy/rockchip/phy-rockchip-dphy.c | 408 +++++++++++++++++++++++
> >>>>  3 files changed, 417 insertions(+)
> >>>>  create mode 100644 drivers/phy/rockchip/phy-rockchip-dphy.c
> >>>>
> >>>> diff --git a/drivers/phy/rockchip/Kconfig b/drivers/phy/rockchip/Kconfig
> >>>> index c454c90cd99e..afd072f135e6 100644
> >>>> --- a/drivers/phy/rockchip/Kconfig
> >>>> +++ b/drivers/phy/rockchip/Kconfig
> >>>> @@ -9,6 +9,14 @@ config PHY_ROCKCHIP_DP
> >>>>  	help
> >>>>  	  Enable this to support the Rockchip Display Port PHY.
> >>>>  
> >>>> +config PHY_ROCKCHIP_DPHY
> >>>> +	tristate "Rockchip MIPI Synopsys DPHY driver"
> > 
> > How much of this PHY is Rockchip-specific ? Would it make sense to turn
> > it into a Synopsys DPHY driver, with some Rockchip glue ? I suppose this
> > could always be done later, if needed (and I also suppose there's no
> > existing driver in drivers/phy/ that support the same Synopsys IP).
> > 
> >>>> +	depends on ARCH_ROCKCHIP && OF
> >>>
> >>> How about (...) || COMPILE_TEST ?
> >>>
> >>>> +	select GENERIC_PHY_MIPI_DPHY
> >>>> +	select GENERIC_PHY
> >>>> +	help
> >>>> +	  Enable this to support the Rockchip MIPI Synopsys DPHY.
> >>>> +
> >>>>  config PHY_ROCKCHIP_EMMC
> >>>>  	tristate "Rockchip EMMC PHY Driver"
> >>>>  	depends on ARCH_ROCKCHIP && OF
> >>>> diff --git a/drivers/phy/rockchip/Makefile b/drivers/phy/rockchip/Makefile
> >>>> index fd21cbaf40dd..f62e9010bcaf 100644
> >>>> --- a/drivers/phy/rockchip/Makefile
> >>>> +++ b/drivers/phy/rockchip/Makefile
> >>>> @@ -1,5 +1,6 @@
> >>>>  # SPDX-License-Identifier: GPL-2.0
> >>>>  obj-$(CONFIG_PHY_ROCKCHIP_DP)		+= phy-rockchip-dp.o
> >>>> +obj-$(CONFIG_PHY_ROCKCHIP_DPHY)		+= phy-rockchip-dphy.o
> >>>>  obj-$(CONFIG_PHY_ROCKCHIP_EMMC)		+= phy-rockchip-emmc.o
> >>>>  obj-$(CONFIG_PHY_ROCKCHIP_INNO_HDMI)	+= phy-rockchip-inno-hdmi.o
> >>>>  obj-$(CONFIG_PHY_ROCKCHIP_INNO_USB2)	+= phy-rockchip-inno-usb2.o
> >>>> diff --git a/drivers/phy/rockchip/phy-rockchip-dphy.c b/drivers/phy/rockchip/phy-rockchip-dphy.c
> >>>> new file mode 100644
> >>>> index 000000000000..3a29976c2dff
> >>>> --- /dev/null
> >>>> +++ b/drivers/phy/rockchip/phy-rockchip-dphy.c
> >>>> @@ -0,0 +1,408 @@
> >>>> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> >>>> +/*
> >>>> + * Rockchip MIPI Synopsys DPHY driver
> >>>> + *
> >>>> + * Based on:
> >>>> + *
> >>>> + * Copyright (C) 2016 FuZhou Rockchip Co., Ltd.
> >>>> + * Author: Yakir Yang <ykk@@rock-chips.com>
> >>>> + */
> >>>> +
> >>>> +#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 HS_RX_DATA_LANES_THS_SETTLE_CONTROL	0x75
> >>>> +
> >>>> +#define MAX_DPHY_CLK 8
> >>>> +
> >>>> +#define PHY_TESTEN_ADDR			(0x1 << 16)
> >>>> +#define PHY_TESTEN_DATA			(0x0 << 16)
> >>>> +#define PHY_TESTCLK			(0x1 << 1)
> >>>> +#define PHY_TESTCLR			(0x1 << 0)
> > 
> > Maybe s/0x// for the previous four lines ?
> > 
> >>>> +#define THS_SETTLE_COUNTER_THRESHOLD	0x04
> >>>> +
> >>>> +#define HIWORD_UPDATE(val, mask, shift) \
> >>>> +	((val) << (shift) | (mask) << ((shift) + 16))
> > 
> > As you use this in a single place, I would inline it, possibly with a
> > small comment that explains what's happening.
> > 
> >>>> +
> >>>> +#define GRF_SOC_CON12                           0x0274
> >>>> +
> >>>> +#define GRF_EDP_REF_CLK_SEL_INTER_HIWORD_MASK   BIT(20)
> >>>> +#define GRF_EDP_REF_CLK_SEL_INTER               BIT(4)
> >>>> +
> >>>> +#define GRF_EDP_PHY_SIDDQ_HIWORD_MASK           BIT(21)
> >>>> +#define GRF_EDP_PHY_SIDDQ_ON                    0
> >>>> +#define GRF_EDP_PHY_SIDDQ_OFF                   BIT(5)
> > 
> > I would recommend aligning the value of of all macros in the same way.
> > 
> >>>> +
> >>>> +struct hsfreq_range {
> >>>> +	u32 range_h;
> > 
> > The structure would be more compact if you turned this into a u16.
> > 
> >>>> +	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}
> > 
> > Maybe s/{/{ / and s/}/ }/ to give it a bit more air ? :-)
> > 
> >>>> +};
> >>>> +
> >>>> +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 {
> >>>> +	u32 offset;
> >>>> +	u32 mask;
> >>>> +	u32 shift;
> > 
> > The offset should hold in 16 bits and the mask and shift in 8 bits. That
> > would save space in the table below.
> > 
> >>>> +};
> >>>> +
> >>>> +#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),
> > 
> > The annoying part with such an indirection is that you can't really
> > write multiple fields in a single register with a single operation.
> > Is the register mapping completely different between the rk3288 and the
> > rk3399, or are the fields grouped in registers in a similar way ? In the
> > latter case we could possibly optimise it.
> 
> This would be the rk3288 version:
> 
> +static const struct dphy_reg rk3288_grf_dphy_regs[] = {
> +	[GRF_CON_DISABLE_ISP] = PHY_REG(RK3288_GRF_SOC_CON6, 1, 0),
> +	[GRF_CON_ISP_DPHY_SEL] = PHY_REG(RK3288_GRF_SOC_CON6, 1, 1),
> +	[GRF_DSI_CSI_TESTBUS_SEL] = PHY_REG(RK3288_GRF_SOC_CON6, 1, 14),
> +	[GRF_DPHY_TX0_TURNDISABLE] = PHY_REG(RK3288_GRF_SOC_CON8, 4, 0),
> +	[GRF_DPHY_TX0_FORCERXMODE] = PHY_REG(RK3288_GRF_SOC_CON8, 4, 4),
> +	[GRF_DPHY_TX0_FORCETXSTOPMODE] = PHY_REG(RK3288_GRF_SOC_CON8, 4, 8),
> +	[GRF_DPHY_TX1RX1_TURNDISABLE] = PHY_REG(RK3288_GRF_SOC_CON9, 4, 0),
> +	[GRF_DPHY_TX1RX1_FORCERXMODE] = PHY_REG(RK3288_GRF_SOC_CON9, 4, 4),
> +	[GRF_DPHY_TX1RX1_FORCETXSTOPMODE] = PHY_REG(RK3288_GRF_SOC_CON9, 4, 8),
> +	[GRF_DPHY_TX1RX1_ENABLE] = PHY_REG(RK3288_GRF_SOC_CON9, 4, 12),
> +	[GRF_DPHY_RX0_TURNDISABLE] = PHY_REG(RK3288_GRF_SOC_CON10, 4, 0),
> +	[GRF_DPHY_RX0_FORCERXMODE] = PHY_REG(RK3288_GRF_SOC_CON10, 4, 4),
> +	[GRF_DPHY_RX0_FORCETXSTOPMODE] = PHY_REG(RK3288_GRF_SOC_CON10, 4, 8),
> +	[GRF_DPHY_RX0_ENABLE] = PHY_REG(RK3288_GRF_SOC_CON10, 4, 12),
> +	[GRF_DPHY_RX0_TESTCLR] = PHY_REG(RK3288_GRF_SOC_CON14, 1, 0),
> +	[GRF_DPHY_RX0_TESTCLK] = PHY_REG(RK3288_GRF_SOC_CON14, 1, 1),
> +	[GRF_DPHY_RX0_TESTEN] = PHY_REG(RK3288_GRF_SOC_CON14, 1, 2),
> +	[GRF_DPHY_RX0_TESTDIN] = PHY_REG(RK3288_GRF_SOC_CON14, 8, 3),
> +	[GRF_DPHY_TX1RX1_ENABLECLK] = PHY_REG(RK3288_GRF_SOC_CON14, 1, 12),
> +	[GRF_DPHY_RX1_SRC_SEL] = PHY_REG(RK3288_GRF_SOC_CON14, 1, 13),
> +	[GRF_DPHY_TX1RX1_MASTERSLAVEZ] = PHY_REG(RK3288_GRF_SOC_CON14, 1, 14),
> +	[GRF_DPHY_TX1RX1_BASEDIR] = PHY_REG(RK3288_GRF_SOC_CON14, 1, 15),
> +	[GRF_DPHY_RX0_TURNREQUEST] = PHY_REG(RK3288_GRF_SOC_CON15, 4, 0),
> +	[GRF_DPHY_TX1RX1_TURNREQUEST] = PHY_REG(RK3288_GRF_SOC_CON15, 4, 4),
> +	[GRF_DPHY_TX0_TURNREQUEST] = PHY_REG(RK3288_GRF_SOC_CON15, 3, 8),
> +	[GRF_DVP_V18SEL] = PHY_REG(RK3288_GRF_IO_VSEL, 1, 1),
> +	[GRF_DPHY_RX0_TESTDOUT] = PHY_REG(RK3288_GRF_SOC_STATUS21, 8, 0),
> +};
> 
> Which seems different mask and shifts from rk3399. If you have any ideas in
> how to optimize this I would appreciate it.

It would be tricky indeed :-( Nevermind for now.

> >>>> +};
> >>>> +
> >>>> +struct dphy_drv_data {
> >>>> +	const char * const *clks;
> >>>> +	int num_clks;
> > 
> > This is never negative, you can make it an unsigned int.
> > 
> >>>> +	const struct hsfreq_range *hsfreq_ranges;
> >>>> +	int num_hsfreq_ranges;
> > 
> > Same here.
> > 
> >>>> +	const struct dphy_reg *regs;
> >>>> +};
> >>>> +
> >>>> +struct rockchip_dphy {
> >>>> +	struct device *dev;
> >>>> +	struct regmap *grf;
> >>>> +	const struct dphy_reg *grf_regs;
> >>>> +	struct clk_bulk_data clks[MAX_DPHY_CLK];
> >>>> +
> >>>> +	const struct dphy_drv_data *drv_data;
> >>>> +	struct phy_configure_opts_mipi_dphy config;
> >>>> +};
> >>>> +
> >>>> +static inline void write_grf_reg(struct rockchip_dphy *priv,
> >>>> +				 int index, u8 value)
> > 
> > Maybe unsigned int index ?
> > 
> >>>> +{
> >>>> +	const struct dphy_reg *reg = &priv->grf_regs[index];
> >>>> +	unsigned int val = HIWORD_UPDATE(value, reg->mask, reg->shift);
> >>>> +
> >>>> +	WARN_ON(!reg->offset);
> >>>> +	regmap_write(priv->grf, reg->offset, val);
> >>>> +}
> >>>> +
> >>>> +static void mipidphy0_wr_reg(struct rockchip_dphy *priv,
> >>>> +			     u8 test_code, u8 test_data)
> > 
> > Function (and structure) names have different prefixes, would it make
> > sense to standardise them ? Maybe rockchip_dphy_ ? Or rk_dphy_ for a
> > shorter version ? This could become rk_dphy_write_dphy(), and the
> > previous function rk_dphy_write_grf().
> > 
> >>>> +{
> >>>> +	/*
> >>>> +	 * 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.
> >>>> +	 */
> > 
> > I've never understood why PHYs tend to have a register named TEST that
> > contains way more than test data :-)
> > 
> >>>> +	write_grf_reg(priv, GRF_DPHY_RX0_TESTCLK, 1);
> >>>> +	write_grf_reg(priv, GRF_DPHY_RX0_TESTDIN, test_code);
> >>>> +	write_grf_reg(priv, GRF_DPHY_RX0_TESTEN, 1);
> >>>> +	write_grf_reg(priv, GRF_DPHY_RX0_TESTCLK, 0);
> >>>> +	write_grf_reg(priv, GRF_DPHY_RX0_TESTEN, 0);
> >>>> +	write_grf_reg(priv, GRF_DPHY_RX0_TESTDIN, test_data);
> >>>> +	write_grf_reg(priv, GRF_DPHY_RX0_TESTCLK, 1);
> >>>> +}
> >>>> +
> >>>> +/* should be move to power_on */
> > 
> > s/move/moved/
> > 
> > Do you mean merging the two functions together ? What prevents from
> > doing so ? 
> 
> Nothing really, this is a left over command as mipidphy_rx_stream_on() is already
> being called from power_on, and I don't think we should merge it because
> in the future we'll probably going to have mipidphy_txrx_stream_on() for dphy1.

Fine with me, let's just remove the comment then.

> >>>> +static int mipidphy_rx_stream_on(struct rockchip_dphy *priv)
> >>>> +{
> >>>> +	const struct dphy_drv_data *drv_data = priv->drv_data;
> >>>> +	const struct hsfreq_range *hsfreq_ranges = drv_data->hsfreq_ranges;
> >>>> +	struct phy_configure_opts_mipi_dphy *config = &priv->config;
> >>>> +	unsigned int i, hsfreq = 0, data_rate_mbps = config->hs_clk_rate;
> >>>> +	int num_hsfreq_ranges = drv_data->num_hsfreq_ranges;
> >>>> +
> >>>> +	do_div(data_rate_mbps, 1000 * 1000);
> >>>> +
> >>>> +	dev_dbg(priv->dev, "%s: lanes %d - data_rate_mbps %u\n",
> >>>> +		__func__, config->lanes, data_rate_mbps);
> >>>> +
> >>>> +	for (i = 0; i < num_hsfreq_ranges; i++) {
> >>>> +		if (hsfreq_ranges[i].range_h >= data_rate_mbps) {
> >>>> +			hsfreq = hsfreq_ranges[i].cfg_bit;
> >>>> +			break;
> >>>> +		}
> >>>> +	}
> > 
> > As num_hsfreq_ranges and hsfreq_ranges are only used in this loop, I
> > would remove the local variables.
> > 
> >>>> +
> >>>> +	write_grf_reg(priv, GRF_DPHY_RX0_FORCERXMODE, 0);
> >>>> +	write_grf_reg(priv, GRF_DPHY_RX0_FORCETXSTOPMODE, 0);
> >>>> +
> >>>> +	/* Disable lan turn around, which is ignored in receive mode */
> > 
> > Is it "lan turn around", or "lane turn around" ?
> > 
> >>>> +	write_grf_reg(priv, GRF_DPHY_RX0_TURNREQUEST, 0);
> >>>> +	write_grf_reg(priv, GRF_DPHY_RX0_TURNDISABLE, 0xf);
> >>>> +
> >>>> +	write_grf_reg(priv, GRF_DPHY_RX0_ENABLE, GENMASK(config->lanes - 1, 0));
> >>>> +
> >>>> +	/* dphy start */
> >>>> +	write_grf_reg(priv, GRF_DPHY_RX0_TESTCLK, 1);
> >>>> +	write_grf_reg(priv, GRF_DPHY_RX0_TESTCLR, 1);
> >>>> +	usleep_range(100, 150);
> >>>> +	write_grf_reg(priv, GRF_DPHY_RX0_TESTCLR, 0);
> >>>> +	usleep_range(100, 150);
> >>>> +
> >>>> +	/* set clock lane */
> >>>> +	/* HS hsfreq_range & lane 0  settle bypass */
> >>>> +	mipidphy0_wr_reg(priv, CLOCK_LANE_HS_RX_CONTROL, 0);
> >>>> +	/* HS RX Control of lane0 */
> >>>> +	mipidphy0_wr_reg(priv, LANE0_HS_RX_CONTROL, hsfreq << 1);
> >>>> +	/* HS RX Control of lane1 */
> >>>> +	mipidphy0_wr_reg(priv, LANE1_HS_RX_CONTROL, 0);
> >>>> +	/* HS RX Control of lane2 */
> >>>> +	mipidphy0_wr_reg(priv, LANE2_HS_RX_CONTROL, 0);
> >>>> +	/* HS RX Control of lane3 */
> >>>> +	mipidphy0_wr_reg(priv, LANE3_HS_RX_CONTROL, 0);
> > 
> > Does this hardcode usage of a single lane ?
> 
> Rockchip seems to uses TEST* registers to set the hsfreqrange.
> It mentions the test code 0x44 (which is LANE0_HS_RX_CONTROL)
> but it doesn't mention the others lanes.
> 
> Replacing those call by
> mipidphy0_wr_reg(priv, LANEx_HS_RX_CONTROL, hsfreq << 1);
> seems to be working.
> 
> I can check if this changes the datarate (I just need to figure a proper
> way to test this or get some docs).
> 
> Thanks for spotting this.

We've discussed this on IRC, it's not clear if the above code is
incorrect or not. Let's add this to a list of open issues.

> >>>> +	/* HS RX Data Lanes Settle State Time Control */
> >>>> +	mipidphy0_wr_reg(priv, HS_RX_DATA_LANES_THS_SETTLE_CONTROL,
> >>>> +			 THS_SETTLE_COUNTER_THRESHOLD);
> >>>> +
> >>>> +	/* Normal operation */
> >>>> +	mipidphy0_wr_reg(priv, 0x0, 0);
> >>>> +
> >>>> +	return 0;
> >>>> +}
> >>>> +
> >>>> +static int rockchip_dphy_configure(struct phy *phy, union phy_configure_opts *opts)
> >>>> +{
> >>>> +	struct rockchip_dphy *priv = phy_get_drvdata(phy);
> >>>> +	int ret;
> >>>> +
> >>>> +	/* pass with phy_mipi_dphy_get_default_config (with pixel rate?) */
> > 
> > I'm not sure to understand what this means.
> 
> iirc, the question is if we should fail when phy_mipi_dphy_config_validate() fails,
> or if we should use a default config.
> 
> Looking at other examples, is seems that only two drivers call
> phy_mipi_dphy_get_default_config() in a totally diferent context, not in mipi path.
> So I guess I would just remove this comment if this is ok with you.

OK.

> >>>> +	ret = phy_mipi_dphy_config_validate(&opts->mipi_dphy);
> >>>> +	if (ret)
> >>>> +		return ret;
> >>>> +
> >>>> +	memcpy(&priv->config, opts, sizeof(priv->config));
> >>>
> >>> You could to:
> >>>
> >>> 	priv->config = *opts;
> >>>
> >>> Up to you. Some people like memcpy(). :-)
> >>
> >> your way is better thanks!
> >>
> >>>> +
> >>>> +	return 0;
> >>>> +}
> >>>> +
> >>>> +static int rockchip_dphy_power_on(struct phy *phy)
> >>>> +{
> >>>> +	struct rockchip_dphy *priv = phy_get_drvdata(phy);
> >>>> +	int ret;
> >>>> +
> >>>> +	ret = clk_bulk_enable(priv->drv_data->num_clks, priv->clks);
> >>>> +	if (ret)
> >>>> +		return ret;
> >>>> +
> >>>> +	return mipidphy_rx_stream_on(priv);
> > 
> > Should you call clk_bulk_disable() if mipidphy_rx_stream_on() fails ?
> > Actually that function never fails, so I'd make it a void function, and
> > return 0 here.
> 
> Ack, I made it void, I'll send it in the next version.
> 
> > What happens if the clock rate is higher than the maximum supported by
> > the PHY ? Shouldn't rockchip_dphy_configure() fail in that case ?
> 
> This is checked in function mipidphy_rx_stream_on(), if it is higher we just
> configure the maximum supported rate. Is this ok?

I think it would be better to reject that in rockchip_dphy_configure()
in order to let the user of the PHY handle the error as early as
possible.

> >>>> +}
> >>>> +
> >>>> +static int rockchip_dphy_power_off(struct phy *phy)
> >>>> +{
> >>>> +	struct rockchip_dphy *priv = phy_get_drvdata(phy);
> >>>> +
> > 
> > No need to write any register ? That's scary, what will happen on the
> > next power on, when the clocks gets enabled ?
> 
> Just for testing, I hacked the code to only call mipidphy_rx_stream_on() once,
> when streaming for the first time, then I don't call it anymore and starting/stopping
> streaming always works, so I guess it keeps the previous configuration when clocks
> get enabled.
> I wonder if this can be a problem when switching from dphy rx to txrx, but for now
> we just support rx.
> 
> Maybe just calling rk_dphy_write_grf(priv, GRF_DPHY_RX0_ENABLE, 0) is enough.

If that works with disable/enable sequences I think it would be good to
include it.

> >>>> +	clk_bulk_disable(priv->drv_data->num_clks, priv->clks);
> >>>> +	return 0;
> >>>> +}
> >>>> +
> >>>> +static int rockchip_dphy_init(struct phy *phy)
> >>>> +{
> >>>> +	struct rockchip_dphy *priv = phy_get_drvdata(phy);
> >>>> +	int ret;
> >>>> +
> >>>> +	ret = clk_bulk_prepare(priv->drv_data->num_clks, priv->clks);
> >>>
> >>> return ...;
> >>>
> >>>> +	if (ret)
> >>>> +		return ret;
> >>>> +	return 0;
> >>>> +}
> >>>> +
> >>>> +static int rockchip_dphy_exit(struct phy *phy)
> >>>> +{
> >>>> +	struct rockchip_dphy *priv = phy_get_drvdata(phy);
> >>>> +
> >>>> +	clk_bulk_unprepare(priv->drv_data->num_clks, priv->clks);
> >>>> +	return 0;
> >>>> +}
> >>>> +
> >>>> +static const struct phy_ops rockchip_dphy_ops = {
> >>>> +	.power_on	= rockchip_dphy_power_on,
> >>>> +	.power_off	= rockchip_dphy_power_off,
> >>>> +	.init		= rockchip_dphy_init,
> >>>> +	.exit		= rockchip_dphy_exit,
> >>>> +	.configure	= rockchip_dphy_configure,
> >>>> +	.owner		= THIS_MODULE,
> >>>> +};
> >>>> +
> >>>> +static const struct 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,
> >>>
> >>> Do you expect to support more of the similar PHY(s) --- are there such? If
> >>> not, you could put these in the code that uses them.
> >>
> >> Yes, for rk3288 in the future.
> >>
> >>>> +};
> >>>> +
> >>>> +static const struct of_device_id rockchip_dphy_dt_ids[] = {
> >>>> +	{
> >>>> +		.compatible = "rockchip,rk3399-mipi-dphy",
> >>>> +		.data = &rk3399_mipidphy_drv_data,
> >>>> +	},
> >>>> +	{}
> >>>> +};
> >>>> +MODULE_DEVICE_TABLE(of, rockchip_dphy_dt_ids);
> >>>> +
> >>>> +static int rockchip_dphy_probe(struct platform_device *pdev)
> >>>> +{
> >>>> +	struct device *dev = &pdev->dev;
> >>>> +	struct device_node *np = dev->of_node;
> >>>> +	const struct dphy_drv_data *drv_data;
> >>>> +	struct phy_provider *phy_provider;
> >>>> +	const struct of_device_id *of_id;
> >>>> +	struct rockchip_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(&pdev->dev, "Rockchip DPHY driver only suports rx\n");
> > 
> > You can replace pdev->dev with dev here and below.
> > 
> > s/rx/RX mode/ ?
> > 
> >>>> +		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");
> >>>> +		if (IS_ERR(grf)) {
> >>>> +			dev_err(dev, "Can't find GRF syscon\n");
> >>>> +			return -ENODEV;
> >>>> +		}
> >>>> +	}
> >>>> +	priv->grf = grf;
> >>>> +
> >>>> +	of_id = of_match_device(rockchip_dphy_dt_ids, dev);
> >>>> +	if (!of_id)
> >>>> +		return -EINVAL;
> >>>> +
> >>>> +	drv_data = of_id->data;
> >>>> +	priv->grf_regs = drv_data->regs;
> > 
> > Do you have to store grf_regs in priv, or could it be accessed through
> > priv->drv_data->regs ?
> > 
> >>>> +	priv->drv_data = drv_data;
> >>>> +	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, &rockchip_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 rockchip_dphy_driver = {
> >>>> +	.probe = rockchip_dphy_probe,
> >>>> +	.driver = {
> >>>> +		.name	= "rockchip-mipi-dphy",
> >>>> +		.of_match_table = rockchip_dphy_dt_ids,
> >>>> +	},
> >>>> +};
> >>>> +module_platform_driver(rockchip_dphy_driver);
> >>>> +
> >>>> +MODULE_AUTHOR("Ezequiel Garcia <ezequiel@collabora.com>");
> >>>> +MODULE_DESCRIPTION("Rockchip MIPI Synopsys DPHY driver");
> >>>> +MODULE_LICENSE("Dual MIT/GPL");
> > 
> > Overall this is quite good, there are only small issues.
> 
> Thank you a lot for your review

-- 
Regards,

Laurent Pinchart