Message-ID: <28b05c0e-2f68-aecb-536a-c543bcd43de1@collabora.com>
Date:   Wed, 21 Aug 2019 18:46:15 -0300
From:   Helen Koike <helen.koike@...labora.com>
To:     Laurent Pinchart <laurent.pinchart@...asonboard.com>
Cc:     Sakari Ailus <sakari.ailus@....fi>,
        linux-rockchip@...ts.infradead.org, devicetree@...r.kernel.org,
        eddie.cai.linux@...il.com, mchehab@...nel.org, heiko@...ech.de,
        jacob2.chen@...k-chips.com, jeffy.chen@...k-chips.com,
        zyc@...k-chips.com, linux-kernel@...r.kernel.org,
        tfiga@...omium.org, hans.verkuil@...co.com,
        sakari.ailus@...ux.intel.com, kernel@...labora.com,
        ezequiel@...labora.com, linux-media@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, zhengsq@...k-chips.com
Subject: Re: [PATCH v8 04/14] media: rkisp1: add Rockchip MIPI Synopsys DPHY
 driver

Hi Laurent,

Thanks for your review, I just have some comments/questions below.

On 8/15/19 2:54 PM, Laurent Pinchart wrote:
> Hi Helen,
> 
> Thank you for the patch.
> 
> 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@...k-chips.com>
>>>>
>>>> This commit adds a subdev driver for Rockchip MIPI Synopsys DPHY driver
>>>>
>>>> Signed-off-by: Jacob Chen <jacob2.chen@...k-chips.com>
>>>> Signed-off-by: Shunqian Zheng <zhengsq@...k-chips.com>
>>>> Signed-off-by: Tomasz Figa <tfiga@...omium.org>
>>>> [migrate to phy framework]
>>>> Signed-off-by: Ezequiel Garcia <ezequiel@...labora.com>
>>>> [update for upstream]
>>>> Signed-off-by: Helen Koike <helen.koike@...labora.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.

> 
>>>> +};
>>>> +
>>>> +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.

> 
>>>> +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.

> 
>>>> +	/* 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.


>>>> +	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?

> 
>>>> +}
>>>> +
>>>> +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.

> 
>>>> +	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@...labora.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
Helen

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