Re: [PATCH 3/3] phy: rockchip: Add Samsung HDMI/DP Combo PHY driver
From: Andy Yan
Date: Wed Jan 24 2024 - 10:47:30 EST
Hi Cristian:
On 1/24/24 10:42, Andy Yan wrote:
Hi Cristian:
On 1/24/24 08:58, Cristian Ciocaltea wrote:
On 1/22/24 14:14, Sascha Hauer wrote:
On Fri, Jan 19, 2024 at 09:38:03PM +0200, Cristian Ciocaltea wrote:
Add driver for the Rockchip HDMI/eDP TX Combo PHY found on RK3588 SoC.
The PHY is based on a Samsung IP block and supports HDMI 2.1 TMDS, FRL
and eDP links. The maximum data rate is 12Gbps (HDMI 2.1 FRL), while
the minimum is 250Mbps (HDMI 2.1 TMDS).
Co-developed-by: Algea Cao <algea.cao@xxxxxxxxxxxxxx>
Signed-off-by: Algea Cao <algea.cao@xxxxxxxxxxxxxx>
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@xxxxxxxxxxxxx>
---
drivers/phy/rockchip/Kconfig | 8 +
drivers/phy/rockchip/Makefile | 1 +
.../phy/rockchip/phy-rockchip-samsung-hdptx.c | 2045 +++++++++++++++++
3 files changed, 2054 insertions(+)
create mode 100644 drivers/phy/rockchip/phy-rockchip-samsung-hdptx.c
diff --git a/drivers/phy/rockchip/Kconfig b/drivers/phy/rockchip/Kconfig
index 94360fc96a6f..95666ac6aa3b 100644
--- a/drivers/phy/rockchip/Kconfig
+++ b/drivers/phy/rockchip/Kconfig
@@ -83,6 +83,14 @@ config PHY_ROCKCHIP_PCIE
help
Enable this to support the Rockchip PCIe PHY.
+config PHY_ROCKCHIP_SAMSUNG_HDPTX
+ tristate "Rockchip Samsung HDMI/DP Combo PHY driver"
+ depends on (ARCH_ROCKCHIP || COMPILE_TEST) && OF
+ select GENERIC_PHY
+ help
+ Enable this to support the Rockchip HDMI/DP Combo PHY
+ with Samsung IP block.
+
config PHY_ROCKCHIP_SNPS_PCIE3
tristate "Rockchip Snps PCIe3 PHY Driver"
depends on (ARCH_ROCKCHIP && OF) || COMPILE_TEST
diff --git a/drivers/phy/rockchip/Makefile b/drivers/phy/rockchip/Makefile
index 7eab129230d1..3d911304e654 100644
--- a/drivers/phy/rockchip/Makefile
+++ b/drivers/phy/rockchip/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_PHY_ROCKCHIP_INNO_HDMI) += phy-rockchip-inno-hdmi.o
obj-$(CONFIG_PHY_ROCKCHIP_INNO_USB2) += phy-rockchip-inno-usb2.o
obj-$(CONFIG_PHY_ROCKCHIP_NANENG_COMBO_PHY) += phy-rockchip-naneng-combphy.o
obj-$(CONFIG_PHY_ROCKCHIP_PCIE) += phy-rockchip-pcie.o
+obj-$(CONFIG_PHY_ROCKCHIP_SAMSUNG_HDPTX) += phy-rockchip-samsung-hdptx.o
obj-$(CONFIG_PHY_ROCKCHIP_SNPS_PCIE3) += phy-rockchip-snps-pcie3.o
obj-$(CONFIG_PHY_ROCKCHIP_TYPEC) += phy-rockchip-typec.o
obj-$(CONFIG_PHY_ROCKCHIP_USB) += phy-rockchip-usb.o
diff --git a/drivers/phy/rockchip/phy-rockchip-samsung-hdptx.c b/drivers/phy/rockchip/phy-rockchip-samsung-hdptx.c
new file mode 100644
index 000000000000..d8171ea5ce2b
--- /dev/null
+++ b/drivers/phy/rockchip/phy-rockchip-samsung-hdptx.c
@@ -0,0 +1,2045 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2021-2022 Rockchip Electronics Co., Ltd.
+ * Copyright (c) 2024 Collabora Ltd.
+ *
+ * Author: Algea Cao <algea.cao@xxxxxxxxxxxxxx>
+ * Author: Cristian Ciocaltea <cristian.ciocaltea@xxxxxxxxxxxxx>
+ */
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/rational.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+
+#define GRF_HDPTX_CON0 0x00
+#define HDPTX_I_PLL_EN BIT(7)
+#define HDPTX_I_BIAS_EN BIT(6)
+#define HDPTX_I_BGR_EN BIT(5)
+#define GRF_HDPTX_STATUS 0x80
+#define HDPTX_O_PLL_LOCK_DONE BIT(3)
+#define HDPTX_O_PHY_CLK_RDY BIT(2)
+#define HDPTX_O_PHY_RDY BIT(1)
+#define HDPTX_O_SB_RDY BIT(0)
+
+#define CMN_REG0000 0x0000
These register names are not particularly helpful. Maybe use a
#define CMN_REG(x) ((x) * 4)
Instead?
Yes, sounds good.
+
+static int hdptx_lcpll_frl_mode_config(struct rockchip_hdptx_phy *hdptx,
+ u32 rate)
+{
+ u32 bit_rate = rate & DATA_RATE_MASK;
+ u8 color_depth = (rate & COLOR_DEPTH_MASK) ? 1 : 0;
+ const struct lcpll_config *cfg = lcpll_cfg;
+
+ for (; cfg->bit_rate != ~0; cfg++)
+ if (bit_rate == cfg->bit_rate)
+ break;
You could use ARRAY_SIZE() to iterate over the array and save the extra
entry at the end. Likewise for the other arrays used in the driver.
Sure, will do.
+
+ if (cfg->bit_rate == ~0)
+ return -EINVAL;
+
+static int rockchip_hdptx_phy_power_on(struct phy *phy)
+{
+ struct rockchip_hdptx_phy *hdptx = phy_get_drvdata(phy);
+ int bus_width = phy_get_bus_width(hdptx->phy);
+ int bit_rate = bus_width & DATA_RATE_MASK;
What is going on here? bus_width is set to 8 in probe() using
phy_set_bus_width(), but the value you pull out of phy_get_bus_width()
is expected to contain the bit_rate and several other flags.
It looks like you are tunneling flags from some other driver using this
field. Isn't there a better way to accomplish this? If not, I think this
needs some explanation.
Indeed, sorry for missing a comment here. The flags are set by the
bridge driver to enable 10-bit color depth, FRL and EARC. So far I
couldn't find an alternative approach to pass custom data using the PHY API.
At least the variable should be renamed. it's called "bus_width" and it's
passed to functions like hdptx_lcpll_frl_mode_config() which has this
parameter named "rate" which is quite confusing.
I think for the initial support it's not really necessary to implement
all those features. Andy, should we drop them until a better solution
is found?
How about add a PHY_MODE_HDMI to enum phy_mode, and pass this custom data by extend phy_configure_opts
or the submode of phy_set_mode_ext ?
I'm fine with it.
It would be very appreciated if some linux-phy or drm bridge experts can give
some suggestions about how to pass different custom phy modes.
Sascha
Thanks for the review,
Cristian