2021-12-27 10:56:15

by Pratyush Yadav

[permalink] [raw]
Subject: [PATCH v7 0/4] Rx mode support for Cadence DPHY

Hi,

This series adds support for Cadence DPHY Rx driver. It has been split
off from [0] to facilitate easier merging. I have still kept the version
number to maintain continuity with the previous patches. The earlier
version used the same binding for Tx and Rx DPHY. With the separate
driver, I have added a separate binding. But I am still keeping the old
conversion patch in this series since I have already done the work in
converting the binding to yaml, might as well get it merged.

Tested on TI's J721E with OV5640 sensor.

[0] https://patchwork.linuxtv.org/project/linux-media/list/?series=5526&state=%2A&archive=both

Changes in v7:
- Add spaces after { and before } in the bands table.
- Drop the wrapping around the for loop on cdns_dphy_rx_get_band_ctrl().
- Make cdns_dphy_rx_wait_for_bit() inline.
- Print an error message if registering PHY provider fails.

Changes in v6:
- Add a new binding for DPHY Rx.
- Move the DPHY Rx part to a separate driver.
- Drop Rx specific changes from the cdns,dphy.yaml binding. Keep those
in cdns,dphy-rx.yaml

Changes in v5:
- Use the new cdns_dphy_info to specify PHY ops.
- Re-order include in alphabetical order.
- Make bands const.
- Drop num_bands.
- Make i, lanes unsigned.
- Drop the maximum check in cdns_dphy_rx_get_band_ctrl(). Let the loop
complete and return -EOPNOTSUPP when we reach the end.
- Drop the "rate < bands[i].min_rate" check since the bands are in
ascending order.
- Move data_lane_ctrl to start of function and make it static const.

Changes in v4:
- Drop the submode parts. Use a different compatible for the Rx ops.
- Make bands and num_bands static.
- Drop the submode patches. Use a different compatible for Rx mode DPHY
instead.

Changes in v3:
- Use a table to select the band.
- Use a table to poll the data lane ready bits.
- Multiply the DPHY HS clock rate by 2 to get the bit rate since the
clock is DDR.
- Add Rob's R-by.

Changes in v2:
- Drop reg description.
- Add a description for each DPHY clock.
- Rename dphy@... to phy@... in example.
- Add Laurent's R-by.
- Re-order subject prefixes.
- Add power-domain to the example.
- Add Laurent's R-by.
- Re-order subject prefixes.

Pratyush Yadav (4):
phy: cadence: Add Cadence D-PHY Rx driver
phy: dt-bindings: Convert Cadence DPHY binding to YAML
phy: dt-bindings: cdns,dphy: add power-domains property
phy: dt-bindings: Add Cadence D-PHY Rx bindings

.../devicetree/bindings/phy/cdns,dphy-rx.yaml | 42 +++
.../devicetree/bindings/phy/cdns,dphy.txt | 20 --
.../devicetree/bindings/phy/cdns,dphy.yaml | 56 ++++
drivers/phy/cadence/Kconfig | 8 +
drivers/phy/cadence/Makefile | 1 +
drivers/phy/cadence/cdns-dphy-rx.c | 255 ++++++++++++++++++
6 files changed, 362 insertions(+), 20 deletions(-)
create mode 100644 Documentation/devicetree/bindings/phy/cdns,dphy-rx.yaml
delete mode 100644 Documentation/devicetree/bindings/phy/cdns,dphy.txt
create mode 100644 Documentation/devicetree/bindings/phy/cdns,dphy.yaml
create mode 100644 drivers/phy/cadence/cdns-dphy-rx.c

--
2.33.1.835.ge9e5ba39a7



2021-12-27 10:56:17

by Pratyush Yadav

[permalink] [raw]
Subject: [PATCH v7 1/4] phy: cadence: Add Cadence D-PHY Rx driver

The Cadence D-PHY can be configured in Tx (DSI) mode or Rx (CSI) mode.
Both modes have a different programming sequence and share little among
them. In addition, a PHY configured in Tx mode cannot be used in Rx mode
and vice versa. For this reason, create a separate driver for the Rx
mode to make it easier to read and maintain.

Signed-off-by: Pratyush Yadav <[email protected]>

---

Changes in v7:
- Add spaces after { and before } in the bands table.
- Drop the wrapping around the for loop on cdns_dphy_rx_get_band_ctrl().
- Make cdns_dphy_rx_wait_for_bit() inline.
- Print an error message if registering PHY provider fails.

Changes in v6:
- Move to a separate driver.

Changes in v5:
- Use the new cdns_dphy_info to specify PHY ops.
- Re-order include in alphabetical order.
- Make bands const.
- Drop num_bands.
- Make i, lanes unsigned.
- Drop the maximum check in cdns_dphy_rx_get_band_ctrl(). Let the loop
complete and return -EOPNOTSUPP when we reach the end.
- Drop the "rate < bands[i].min_rate" check since the bands are in
ascending order.
- Move data_lane_ctrl to start of function and make it static const.

Changes in v4:
- Drop the submode parts. Use a different compatible for the Rx ops.
- Make bands and num_bands static.

Changes in v3:
- Use a table to select the band.
- Use a table to poll the data lane ready bits.
- Multiply the DPHY HS clock rate by 2 to get the bit rate since the
clock is DDR.

drivers/phy/cadence/Kconfig | 8 +
drivers/phy/cadence/Makefile | 1 +
drivers/phy/cadence/cdns-dphy-rx.c | 255 +++++++++++++++++++++++++++++
3 files changed, 264 insertions(+)
create mode 100644 drivers/phy/cadence/cdns-dphy-rx.c

diff --git a/drivers/phy/cadence/Kconfig b/drivers/phy/cadence/Kconfig
index a62910ff5591..1adde2d99ae7 100644
--- a/drivers/phy/cadence/Kconfig
+++ b/drivers/phy/cadence/Kconfig
@@ -22,6 +22,14 @@ config PHY_CADENCE_DPHY
system. If M is selected, the module will be called
cdns-dphy.

+config PHY_CADENCE_DPHY_RX
+ tristate "Cadence D-PHY Rx Support"
+ depends on HAS_IOMEM && OF
+ select GENERIC_PHY
+ select GENERIC_PHY_MIPI_DPHY
+ help
+ Support for Cadence D-PHY in Rx configuration.
+
config PHY_CADENCE_SIERRA
tristate "Cadence Sierra PHY Driver"
depends on OF && HAS_IOMEM && RESET_CONTROLLER
diff --git a/drivers/phy/cadence/Makefile b/drivers/phy/cadence/Makefile
index 26e16bd34efe..e17f035ddece 100644
--- a/drivers/phy/cadence/Makefile
+++ b/drivers/phy/cadence/Makefile
@@ -1,5 +1,6 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-$(CONFIG_PHY_CADENCE_TORRENT) += phy-cadence-torrent.o
obj-$(CONFIG_PHY_CADENCE_DPHY) += cdns-dphy.o
+obj-$(CONFIG_PHY_CADENCE_DPHY_RX) += cdns-dphy-rx.o
obj-$(CONFIG_PHY_CADENCE_SIERRA) += phy-cadence-sierra.o
obj-$(CONFIG_PHY_CADENCE_SALVO) += phy-cadence-salvo.o
diff --git a/drivers/phy/cadence/cdns-dphy-rx.c b/drivers/phy/cadence/cdns-dphy-rx.c
new file mode 100644
index 000000000000..47a5b67ded58
--- /dev/null
+++ b/drivers/phy/cadence/cdns-dphy-rx.c
@@ -0,0 +1,255 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2021 Texas Instruments Incorporated - https://www.ti.com/
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/phy/phy.h>
+#include <linux/phy/phy-mipi-dphy.h>
+#include <linux/platform_device.h>
+
+#define DPHY_PMA_CMN(reg) (reg)
+#define DPHY_PCS(reg) (0xb00 + (reg))
+#define DPHY_ISO(reg) (0xc00 + (reg))
+
+#define DPHY_CMN_SSM DPHY_PMA_CMN(0x20)
+#define DPHY_CMN_RX_MODE_EN BIT(10)
+#define DPHY_CMN_RX_BANDGAP_TIMER_MASK GENMASK(8, 1)
+#define DPHY_CMN_SSM_EN BIT(0)
+
+#define DPHY_CMN_RX_BANDGAP_TIMER 0x14
+
+#define DPHY_BAND_CFG DPHY_PCS(0x0)
+#define DPHY_BAND_CFG_RIGHT_BAND GENMASK(9, 5)
+#define DPHY_BAND_CFG_LEFT_BAND GENMASK(4, 0)
+
+#define DPHY_POWER_ISLAND_EN_DATA DPHY_PCS(0x8)
+#define DPHY_POWER_ISLAND_EN_DATA_VAL 0xaaaaaaaa
+
+#define DPHY_POWER_ISLAND_EN_CLK DPHY_PCS(0xc)
+#define DPHY_POWER_ISLAND_EN_CLK_VAL 0xaa
+
+#define DPHY_ISO_CL_CTRL_L DPHY_ISO(0x10)
+#define DPHY_ISO_DL_CTRL_L0 DPHY_ISO(0x14)
+#define DPHY_ISO_DL_CTRL_L1 DPHY_ISO(0x20)
+#define DPHY_ISO_DL_CTRL_L2 DPHY_ISO(0x30)
+#define DPHY_ISO_DL_CTRL_L3 DPHY_ISO(0x3c)
+
+#define DPHY_ISO_LANE_READY_BIT 0
+#define DPHY_ISO_LANE_READY_TIMEOUT_MS 100UL
+
+#define DPHY_LANES_MIN 1
+#define DPHY_LANES_MAX 4
+
+struct cdns_dphy_rx {
+ void __iomem *regs;
+ struct device *dev;
+ struct phy *phy;
+};
+
+struct cdns_dphy_rx_band {
+ /* Rates are in Mbps. */
+ unsigned int min_rate;
+ unsigned int max_rate;
+};
+
+/* Order of bands is important since the index is the band number. */
+static const struct cdns_dphy_rx_band bands[] = {
+ { 80, 100 }, { 100, 120 }, { 120, 160 }, { 160, 200 }, { 200, 240 },
+ { 240, 280 }, { 280, 320 }, { 320, 360 }, { 360, 400 }, { 400, 480 },
+ { 480, 560 }, { 560, 640 }, { 640, 720 }, { 720, 800 }, { 800, 880 },
+ { 880, 1040 }, { 1040, 1200 }, { 1200, 1350 }, { 1350, 1500 },
+ { 1500, 1750 }, { 1750, 2000 }, { 2000, 2250 }, { 2250, 2500 }
+};
+
+static int cdns_dphy_rx_power_on(struct phy *phy)
+{
+ struct cdns_dphy_rx *dphy = phy_get_drvdata(phy);
+
+ /* Start RX state machine. */
+ writel(DPHY_CMN_SSM_EN | DPHY_CMN_RX_MODE_EN |
+ FIELD_PREP(DPHY_CMN_RX_BANDGAP_TIMER_MASK,
+ DPHY_CMN_RX_BANDGAP_TIMER),
+ dphy->regs + DPHY_CMN_SSM);
+
+ return 0;
+}
+
+static int cdns_dphy_rx_power_off(struct phy *phy)
+{
+ struct cdns_dphy_rx *dphy = phy_get_drvdata(phy);
+
+ writel(0, dphy->regs + DPHY_CMN_SSM);
+
+ return 0;
+}
+
+static int cdns_dphy_rx_get_band_ctrl(unsigned long hs_clk_rate)
+{
+ unsigned int rate, i;
+
+ rate = hs_clk_rate / 1000000UL;
+ /* Since CSI-2 clock is DDR, the bit rate is twice the clock rate. */
+ rate *= 2;
+
+ if (rate < bands[0].min_rate)
+ return -EOPNOTSUPP;
+
+ for (i = 0; i < ARRAY_SIZE(bands); i++)
+ if (rate < bands[i].max_rate)
+ return i;
+
+ return -EOPNOTSUPP;
+}
+
+static inline int cdns_dphy_rx_wait_for_bit(void __iomem *addr,
+ unsigned int bit)
+{
+ u32 val;
+
+ return readl_relaxed_poll_timeout(addr, val, val & BIT(bit), 10,
+ DPHY_ISO_LANE_READY_TIMEOUT_MS * 1000);
+}
+
+static int cdns_dphy_rx_wait_lane_ready(struct cdns_dphy_rx *dphy,
+ unsigned int lanes)
+{
+ static const u32 data_lane_ctrl[] = {DPHY_ISO_DL_CTRL_L0,
+ DPHY_ISO_DL_CTRL_L1,
+ DPHY_ISO_DL_CTRL_L2,
+ DPHY_ISO_DL_CTRL_L3};
+ void __iomem *reg = dphy->regs;
+ unsigned int i;
+ int ret;
+
+ /* Data lanes. Minimum one lane is mandatory. */
+ if (lanes < DPHY_LANES_MIN || lanes > DPHY_LANES_MAX)
+ return -EINVAL;
+
+ /* Clock lane */
+ ret = cdns_dphy_rx_wait_for_bit(reg + DPHY_ISO_CL_CTRL_L,
+ DPHY_ISO_LANE_READY_BIT);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < lanes; i++) {
+ ret = cdns_dphy_rx_wait_for_bit(reg + data_lane_ctrl[i],
+ DPHY_ISO_LANE_READY_BIT);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int cdns_dphy_rx_configure(struct phy *phy,
+ union phy_configure_opts *opts)
+{
+ struct cdns_dphy_rx *dphy = phy_get_drvdata(phy);
+ unsigned int reg;
+ int band_ctrl, ret;
+
+ band_ctrl = cdns_dphy_rx_get_band_ctrl(opts->mipi_dphy.hs_clk_rate);
+ if (band_ctrl < 0)
+ return band_ctrl;
+
+ reg = FIELD_PREP(DPHY_BAND_CFG_LEFT_BAND, band_ctrl) |
+ FIELD_PREP(DPHY_BAND_CFG_RIGHT_BAND, band_ctrl);
+ writel(reg, dphy->regs + DPHY_BAND_CFG);
+
+ /*
+ * Set the required power island phase 2 time. This is mandated by DPHY
+ * specs.
+ */
+ reg = DPHY_POWER_ISLAND_EN_DATA_VAL;
+ writel(reg, dphy->regs + DPHY_POWER_ISLAND_EN_DATA);
+ reg = DPHY_POWER_ISLAND_EN_CLK_VAL;
+ writel(reg, dphy->regs + DPHY_POWER_ISLAND_EN_CLK);
+
+ ret = cdns_dphy_rx_wait_lane_ready(dphy, opts->mipi_dphy.lanes);
+ if (ret) {
+ dev_err(dphy->dev, "DPHY wait for lane ready timeout\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int cdns_dphy_rx_validate(struct phy *phy, enum phy_mode mode,
+ int submode, union phy_configure_opts *opts)
+{
+ int ret;
+
+ if (mode != PHY_MODE_MIPI_DPHY)
+ return -EINVAL;
+
+ ret = cdns_dphy_rx_get_band_ctrl(opts->mipi_dphy.hs_clk_rate);
+ if (ret < 0)
+ return ret;
+
+ return phy_mipi_dphy_config_validate(&opts->mipi_dphy);
+}
+
+static const struct phy_ops cdns_dphy_rx_ops = {
+ .power_on = cdns_dphy_rx_power_on,
+ .power_off = cdns_dphy_rx_power_off,
+ .configure = cdns_dphy_rx_configure,
+ .validate = cdns_dphy_rx_validate,
+};
+
+static int cdns_dphy_rx_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct phy_provider *provider;
+ struct cdns_dphy_rx *dphy;
+
+ dphy = devm_kzalloc(dev, sizeof(*dphy), GFP_KERNEL);
+ if (!dphy)
+ return -ENOMEM;
+
+ dev_set_drvdata(dev, dphy);
+ dphy->dev = dev;
+
+ dphy->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(dphy->regs))
+ return PTR_ERR(dphy->regs);
+
+ dphy->phy = devm_phy_create(dev, NULL, &cdns_dphy_rx_ops);
+ if (IS_ERR(dphy->phy)) {
+ dev_err(dev, "Failed to create PHY: %d\n", PTR_ERR(dphy->phy));
+ return PTR_ERR(dphy->phy);
+ }
+
+ phy_set_drvdata(dphy->phy, dphy);
+ provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+ if (IS_ERR(provider)) {
+ dev_err(dev, "Failed to register PHY provider: %d\n",
+ PTR_ERR(provider));
+ return PTR_ERR(provider);
+ }
+
+ return 0;
+}
+
+static const struct of_device_id cdns_dphy_rx_of_match[] = {
+ { .compatible = "cdns,dphy-rx" },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, cdns_dphy_rx_of_match);
+
+static struct platform_driver cdns_dphy_rx_platform_driver = {
+ .probe = cdns_dphy_rx_probe,
+ .driver = {
+ .name = "cdns-mipi-dphy-rx",
+ .of_match_table = cdns_dphy_rx_of_match,
+ },
+};
+module_platform_driver(cdns_dphy_rx_platform_driver);
+
+MODULE_AUTHOR("Pratyush Yadav <[email protected]>");
+MODULE_DESCRIPTION("Cadence D-PHY Rx Driver");
+MODULE_LICENSE("GPL v2");
--
2.33.1.835.ge9e5ba39a7


2021-12-27 10:56:19

by Pratyush Yadav

[permalink] [raw]
Subject: [PATCH v7 4/4] phy: dt-bindings: Add Cadence D-PHY Rx bindings

The Rx mode DPHY is different from Tx mode DPHY. Add a separate binding
for it.

Signed-off-by: Pratyush Yadav <[email protected]>

---

(no changes since v6)

Changes in v6:
- Add a new binding for DPHY Rx.

.../devicetree/bindings/phy/cdns,dphy-rx.yaml | 42 +++++++++++++++++++
1 file changed, 42 insertions(+)
create mode 100644 Documentation/devicetree/bindings/phy/cdns,dphy-rx.yaml

diff --git a/Documentation/devicetree/bindings/phy/cdns,dphy-rx.yaml b/Documentation/devicetree/bindings/phy/cdns,dphy-rx.yaml
new file mode 100644
index 000000000000..07be031d82e6
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/cdns,dphy-rx.yaml
@@ -0,0 +1,42 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/phy/cdns,dphy-rx.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Cadence DPHY Rx Device Tree Bindings
+
+maintainers:
+ - Pratyush Yadav <[email protected]>
+
+properties:
+ compatible:
+ items:
+ - const: cdns,dphy-rx
+
+ reg:
+ maxItems: 1
+
+ "#phy-cells":
+ const: 0
+
+ power-domains:
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+ - "#phy-cells"
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/soc/ti,sci_pm_domain.h>
+
+ dphy0: phy@4580000 {
+ compatible = "cdns,dphy-rx";
+ reg = <0x4580000 0x1100>;
+ #phy-cells = <0>;
+ power-domains = <&k3_pds 147 TI_SCI_PD_EXCLUSIVE>;
+ };
--
2.33.1.835.ge9e5ba39a7


2021-12-27 10:56:20

by Pratyush Yadav

[permalink] [raw]
Subject: [PATCH v7 2/4] phy: dt-bindings: Convert Cadence DPHY binding to YAML

Convert Cadence DPHY binding to YAML.

Signed-off-by: Pratyush Yadav <[email protected]>
Reviewed-by: Laurent Pinchart <[email protected]>
Reviewed-by: Rob Herring <[email protected]>

---

(no changes since v3)

Changes in v3:
- Add Rob's R-by.

Changes in v2:
- Drop reg description.
- Add a description for each DPHY clock.
- Rename dphy@... to phy@... in example.
- Add Laurent's R-by.
- Re-order subject prefixes.

.../devicetree/bindings/phy/cdns,dphy.txt | 20 --------
.../devicetree/bindings/phy/cdns,dphy.yaml | 51 +++++++++++++++++++
2 files changed, 51 insertions(+), 20 deletions(-)
delete mode 100644 Documentation/devicetree/bindings/phy/cdns,dphy.txt
create mode 100644 Documentation/devicetree/bindings/phy/cdns,dphy.yaml

diff --git a/Documentation/devicetree/bindings/phy/cdns,dphy.txt b/Documentation/devicetree/bindings/phy/cdns,dphy.txt
deleted file mode 100644
index 1095bc4e72d9..000000000000
--- a/Documentation/devicetree/bindings/phy/cdns,dphy.txt
+++ /dev/null
@@ -1,20 +0,0 @@
-Cadence DPHY
-============
-
-Cadence DPHY block.
-
-Required properties:
-- compatible: should be set to "cdns,dphy".
-- reg: physical base address and length of the DPHY registers.
-- clocks: DPHY reference clocks.
-- clock-names: must contain "psm" and "pll_ref".
-- #phy-cells: must be set to 0.
-
-Example:
- dphy0: dphy@fd0e0000{
- compatible = "cdns,dphy";
- reg = <0x0 0xfd0e0000 0x0 0x1000>;
- clocks = <&psm_clk>, <&pll_ref_clk>;
- clock-names = "psm", "pll_ref";
- #phy-cells = <0>;
- };
diff --git a/Documentation/devicetree/bindings/phy/cdns,dphy.yaml b/Documentation/devicetree/bindings/phy/cdns,dphy.yaml
new file mode 100644
index 000000000000..b90a58773bf2
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/cdns,dphy.yaml
@@ -0,0 +1,51 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/phy/cdns,dphy.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Cadence DPHY Device Tree Bindings
+
+maintainers:
+ - Pratyush Yadav <[email protected]>
+
+properties:
+ compatible:
+ items:
+ - const: cdns,dphy
+
+ reg:
+ maxItems: 1
+
+ clocks:
+ items:
+ - description: PMA state machine clock
+ - description: PLL reference clock
+
+ clock-names:
+ items:
+ - const: psm
+ - const: pll_ref
+
+ "#phy-cells":
+ const: 0
+
+required:
+ - compatible
+ - reg
+ - clocks
+ - clock-names
+ - "#phy-cells"
+
+additionalProperties: false
+
+examples:
+ - |
+
+ dphy0: phy@fd0e0000{
+ compatible = "cdns,dphy";
+ reg = <0xfd0e0000 0x1000>;
+ clocks = <&psm_clk>, <&pll_ref_clk>;
+ clock-names = "psm", "pll_ref";
+ #phy-cells = <0>;
+ };
--
2.33.1.835.ge9e5ba39a7


2021-12-27 16:57:27

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH v7 4/4] phy: dt-bindings: Add Cadence D-PHY Rx bindings

On Mon, 27 Dec 2021 16:25:45 +0530, Pratyush Yadav wrote:
> The Rx mode DPHY is different from Tx mode DPHY. Add a separate binding
> for it.
>
> Signed-off-by: Pratyush Yadav <[email protected]>
>
> ---
>
> (no changes since v6)
>
> Changes in v6:
> - Add a new binding for DPHY Rx.
>
> .../devicetree/bindings/phy/cdns,dphy-rx.yaml | 42 +++++++++++++++++++
> 1 file changed, 42 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/phy/cdns,dphy-rx.yaml
>


Please add Acked-by/Reviewed-by tags when posting new versions. However,
there's no need to repost patches *only* to add the tags. The upstream
maintainer will do that for acks received on the version they apply.

If a tag was not added on purpose, please state why and what changed.


2021-12-27 20:49:15

by Pratyush Yadav

[permalink] [raw]
Subject: Re: [PATCH v7 4/4] phy: dt-bindings: Add Cadence D-PHY Rx bindings

Hi Rob,

On 27/12/21 12:57PM, Rob Herring wrote:
> On Mon, 27 Dec 2021 16:25:45 +0530, Pratyush Yadav wrote:
> > The Rx mode DPHY is different from Tx mode DPHY. Add a separate binding
> > for it.
> >
> > Signed-off-by: Pratyush Yadav <[email protected]>
> >
> > ---
> >
> > (no changes since v6)
> >
> > Changes in v6:
> > - Add a new binding for DPHY Rx.
> >
> > .../devicetree/bindings/phy/cdns,dphy-rx.yaml | 42 +++++++++++++++++++
> > 1 file changed, 42 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/phy/cdns,dphy-rx.yaml
> >
>
>
> Please add Acked-by/Reviewed-by tags when posting new versions. However,
> there's no need to repost patches *only* to add the tags. The upstream
> maintainer will do that for acks received on the version they apply.
>
> If a tag was not added on purpose, please state why and what changed.

Sorry. I missed adding your R-by. It was by mistake, since this patch
has not changed since.

--
Regards,
Pratyush Yadav
Texas Instruments Inc.

2021-12-29 23:14:50

by Laurent Pinchart

[permalink] [raw]
Subject: Re: [PATCH v7 4/4] phy: dt-bindings: Add Cadence D-PHY Rx bindings

Hi Pratyush,

Thank you for the patch.

On Mon, Dec 27, 2021 at 04:25:45PM +0530, Pratyush Yadav wrote:
> The Rx mode DPHY is different from Tx mode DPHY. Add a separate binding
> for it.
>
> Signed-off-by: Pratyush Yadav <[email protected]>

Reviewed-by: Laurent Pinchart <[email protected]>

> ---
>
> (no changes since v6)
>
> Changes in v6:
> - Add a new binding for DPHY Rx.
>
> .../devicetree/bindings/phy/cdns,dphy-rx.yaml | 42 +++++++++++++++++++
> 1 file changed, 42 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/phy/cdns,dphy-rx.yaml
>
> diff --git a/Documentation/devicetree/bindings/phy/cdns,dphy-rx.yaml b/Documentation/devicetree/bindings/phy/cdns,dphy-rx.yaml
> new file mode 100644
> index 000000000000..07be031d82e6
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/phy/cdns,dphy-rx.yaml
> @@ -0,0 +1,42 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/phy/cdns,dphy-rx.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Cadence DPHY Rx Device Tree Bindings
> +
> +maintainers:
> + - Pratyush Yadav <[email protected]>
> +
> +properties:
> + compatible:
> + items:
> + - const: cdns,dphy-rx
> +
> + reg:
> + maxItems: 1
> +
> + "#phy-cells":
> + const: 0
> +
> + power-domains:
> + maxItems: 1
> +
> +required:
> + - compatible
> + - reg
> + - "#phy-cells"
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/soc/ti,sci_pm_domain.h>
> +
> + dphy0: phy@4580000 {
> + compatible = "cdns,dphy-rx";
> + reg = <0x4580000 0x1100>;
> + #phy-cells = <0>;
> + power-domains = <&k3_pds 147 TI_SCI_PD_EXCLUSIVE>;
> + };

--
Regards,

Laurent Pinchart

2021-12-29 23:30:23

by Laurent Pinchart

[permalink] [raw]
Subject: Re: [PATCH v7 1/4] phy: cadence: Add Cadence D-PHY Rx driver

Hi Pratyush,

Thank you for the patch.

On Mon, Dec 27, 2021 at 04:25:42PM +0530, Pratyush Yadav wrote:
> The Cadence D-PHY can be configured in Tx (DSI) mode or Rx (CSI) mode.
> Both modes have a different programming sequence and share little among
> them. In addition, a PHY configured in Tx mode cannot be used in Rx mode
> and vice versa. For this reason, create a separate driver for the Rx
> mode to make it easier to read and maintain.
>
> Signed-off-by: Pratyush Yadav <[email protected]>
>
> ---
>
> Changes in v7:
> - Add spaces after { and before } in the bands table.
> - Drop the wrapping around the for loop on cdns_dphy_rx_get_band_ctrl().
> - Make cdns_dphy_rx_wait_for_bit() inline.
> - Print an error message if registering PHY provider fails.
>
> Changes in v6:
> - Move to a separate driver.
>
> Changes in v5:
> - Use the new cdns_dphy_info to specify PHY ops.
> - Re-order include in alphabetical order.
> - Make bands const.
> - Drop num_bands.
> - Make i, lanes unsigned.
> - Drop the maximum check in cdns_dphy_rx_get_band_ctrl(). Let the loop
> complete and return -EOPNOTSUPP when we reach the end.
> - Drop the "rate < bands[i].min_rate" check since the bands are in
> ascending order.
> - Move data_lane_ctrl to start of function and make it static const.
>
> Changes in v4:
> - Drop the submode parts. Use a different compatible for the Rx ops.
> - Make bands and num_bands static.
>
> Changes in v3:
> - Use a table to select the band.
> - Use a table to poll the data lane ready bits.
> - Multiply the DPHY HS clock rate by 2 to get the bit rate since the
> clock is DDR.
>
> drivers/phy/cadence/Kconfig | 8 +
> drivers/phy/cadence/Makefile | 1 +
> drivers/phy/cadence/cdns-dphy-rx.c | 255 +++++++++++++++++++++++++++++
> 3 files changed, 264 insertions(+)
> create mode 100644 drivers/phy/cadence/cdns-dphy-rx.c
>
> diff --git a/drivers/phy/cadence/Kconfig b/drivers/phy/cadence/Kconfig
> index a62910ff5591..1adde2d99ae7 100644
> --- a/drivers/phy/cadence/Kconfig
> +++ b/drivers/phy/cadence/Kconfig
> @@ -22,6 +22,14 @@ config PHY_CADENCE_DPHY
> system. If M is selected, the module will be called
> cdns-dphy.
>
> +config PHY_CADENCE_DPHY_RX
> + tristate "Cadence D-PHY Rx Support"
> + depends on HAS_IOMEM && OF
> + select GENERIC_PHY
> + select GENERIC_PHY_MIPI_DPHY
> + help
> + Support for Cadence D-PHY in Rx configuration.
> +
> config PHY_CADENCE_SIERRA
> tristate "Cadence Sierra PHY Driver"
> depends on OF && HAS_IOMEM && RESET_CONTROLLER
> diff --git a/drivers/phy/cadence/Makefile b/drivers/phy/cadence/Makefile
> index 26e16bd34efe..e17f035ddece 100644
> --- a/drivers/phy/cadence/Makefile
> +++ b/drivers/phy/cadence/Makefile
> @@ -1,5 +1,6 @@
> # SPDX-License-Identifier: GPL-2.0-only
> obj-$(CONFIG_PHY_CADENCE_TORRENT) += phy-cadence-torrent.o
> obj-$(CONFIG_PHY_CADENCE_DPHY) += cdns-dphy.o
> +obj-$(CONFIG_PHY_CADENCE_DPHY_RX) += cdns-dphy-rx.o
> obj-$(CONFIG_PHY_CADENCE_SIERRA) += phy-cadence-sierra.o
> obj-$(CONFIG_PHY_CADENCE_SALVO) += phy-cadence-salvo.o
> diff --git a/drivers/phy/cadence/cdns-dphy-rx.c b/drivers/phy/cadence/cdns-dphy-rx.c
> new file mode 100644
> index 000000000000..47a5b67ded58
> --- /dev/null
> +++ b/drivers/phy/cadence/cdns-dphy-rx.c
> @@ -0,0 +1,255 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2021 Texas Instruments Incorporated - https://www.ti.com/
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/bitops.h>
> +#include <linux/io.h>
> +#include <linux/iopoll.h>
> +#include <linux/module.h>
> +#include <linux/phy/phy.h>
> +#include <linux/phy/phy-mipi-dphy.h>
> +#include <linux/platform_device.h>
> +
> +#define DPHY_PMA_CMN(reg) (reg)
> +#define DPHY_PCS(reg) (0xb00 + (reg))
> +#define DPHY_ISO(reg) (0xc00 + (reg))
> +
> +#define DPHY_CMN_SSM DPHY_PMA_CMN(0x20)
> +#define DPHY_CMN_RX_MODE_EN BIT(10)
> +#define DPHY_CMN_RX_BANDGAP_TIMER_MASK GENMASK(8, 1)
> +#define DPHY_CMN_SSM_EN BIT(0)
> +
> +#define DPHY_CMN_RX_BANDGAP_TIMER 0x14
> +
> +#define DPHY_BAND_CFG DPHY_PCS(0x0)
> +#define DPHY_BAND_CFG_RIGHT_BAND GENMASK(9, 5)
> +#define DPHY_BAND_CFG_LEFT_BAND GENMASK(4, 0)
> +
> +#define DPHY_POWER_ISLAND_EN_DATA DPHY_PCS(0x8)
> +#define DPHY_POWER_ISLAND_EN_DATA_VAL 0xaaaaaaaa
> +
> +#define DPHY_POWER_ISLAND_EN_CLK DPHY_PCS(0xc)
> +#define DPHY_POWER_ISLAND_EN_CLK_VAL 0xaa
> +
> +#define DPHY_ISO_CL_CTRL_L DPHY_ISO(0x10)
> +#define DPHY_ISO_DL_CTRL_L0 DPHY_ISO(0x14)
> +#define DPHY_ISO_DL_CTRL_L1 DPHY_ISO(0x20)
> +#define DPHY_ISO_DL_CTRL_L2 DPHY_ISO(0x30)
> +#define DPHY_ISO_DL_CTRL_L3 DPHY_ISO(0x3c)
> +
> +#define DPHY_ISO_LANE_READY_BIT 0
> +#define DPHY_ISO_LANE_READY_TIMEOUT_MS 100UL
> +
> +#define DPHY_LANES_MIN 1
> +#define DPHY_LANES_MAX 4
> +
> +struct cdns_dphy_rx {
> + void __iomem *regs;
> + struct device *dev;
> + struct phy *phy;
> +};
> +
> +struct cdns_dphy_rx_band {
> + /* Rates are in Mbps. */
> + unsigned int min_rate;
> + unsigned int max_rate;
> +};
> +
> +/* Order of bands is important since the index is the band number. */
> +static const struct cdns_dphy_rx_band bands[] = {
> + { 80, 100 }, { 100, 120 }, { 120, 160 }, { 160, 200 }, { 200, 240 },
> + { 240, 280 }, { 280, 320 }, { 320, 360 }, { 360, 400 }, { 400, 480 },
> + { 480, 560 }, { 560, 640 }, { 640, 720 }, { 720, 800 }, { 800, 880 },
> + { 880, 1040 }, { 1040, 1200 }, { 1200, 1350 }, { 1350, 1500 },
> + { 1500, 1750 }, { 1750, 2000 }, { 2000, 2250 }, { 2250, 2500 }

It could be possible to store only the min or max rate, as
bands[i].max_rate == bands[i+1].min_rate. Up to you.

> +};
> +
> +static int cdns_dphy_rx_power_on(struct phy *phy)
> +{
> + struct cdns_dphy_rx *dphy = phy_get_drvdata(phy);
> +
> + /* Start RX state machine. */
> + writel(DPHY_CMN_SSM_EN | DPHY_CMN_RX_MODE_EN |
> + FIELD_PREP(DPHY_CMN_RX_BANDGAP_TIMER_MASK,
> + DPHY_CMN_RX_BANDGAP_TIMER),
> + dphy->regs + DPHY_CMN_SSM);
> +
> + return 0;
> +}
> +
> +static int cdns_dphy_rx_power_off(struct phy *phy)
> +{
> + struct cdns_dphy_rx *dphy = phy_get_drvdata(phy);
> +
> + writel(0, dphy->regs + DPHY_CMN_SSM);
> +
> + return 0;
> +}
> +
> +static int cdns_dphy_rx_get_band_ctrl(unsigned long hs_clk_rate)
> +{
> + unsigned int rate, i;
> +
> + rate = hs_clk_rate / 1000000UL;
> + /* Since CSI-2 clock is DDR, the bit rate is twice the clock rate. */
> + rate *= 2;
> +
> + if (rate < bands[0].min_rate)
> + return -EOPNOTSUPP;
> +
> + for (i = 0; i < ARRAY_SIZE(bands); i++)
> + if (rate < bands[i].max_rate)
> + return i;
> +
> + return -EOPNOTSUPP;
> +}
> +
> +static inline int cdns_dphy_rx_wait_for_bit(void __iomem *addr,
> + unsigned int bit)
> +{
> + u32 val;
> +
> + return readl_relaxed_poll_timeout(addr, val, val & BIT(bit), 10,
> + DPHY_ISO_LANE_READY_TIMEOUT_MS * 1000);
> +}
> +
> +static int cdns_dphy_rx_wait_lane_ready(struct cdns_dphy_rx *dphy,
> + unsigned int lanes)
> +{
> + static const u32 data_lane_ctrl[] = {DPHY_ISO_DL_CTRL_L0,
> + DPHY_ISO_DL_CTRL_L1,
> + DPHY_ISO_DL_CTRL_L2,
> + DPHY_ISO_DL_CTRL_L3};
> + void __iomem *reg = dphy->regs;
> + unsigned int i;
> + int ret;
> +
> + /* Data lanes. Minimum one lane is mandatory. */
> + if (lanes < DPHY_LANES_MIN || lanes > DPHY_LANES_MAX)
> + return -EINVAL;

How about moving this at the beginning of cdns_dphy_rx_configure(), to
avoid starting the configuration sequence if the parameter is wrong ?

> +
> + /* Clock lane */
> + ret = cdns_dphy_rx_wait_for_bit(reg + DPHY_ISO_CL_CTRL_L,
> + DPHY_ISO_LANE_READY_BIT);
> + if (ret)
> + return ret;
> +
> + for (i = 0; i < lanes; i++) {
> + ret = cdns_dphy_rx_wait_for_bit(reg + data_lane_ctrl[i],
> + DPHY_ISO_LANE_READY_BIT);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int cdns_dphy_rx_configure(struct phy *phy,
> + union phy_configure_opts *opts)
> +{
> + struct cdns_dphy_rx *dphy = phy_get_drvdata(phy);
> + unsigned int reg;
> + int band_ctrl, ret;
> +
> + band_ctrl = cdns_dphy_rx_get_band_ctrl(opts->mipi_dphy.hs_clk_rate);
> + if (band_ctrl < 0)
> + return band_ctrl;
> +
> + reg = FIELD_PREP(DPHY_BAND_CFG_LEFT_BAND, band_ctrl) |
> + FIELD_PREP(DPHY_BAND_CFG_RIGHT_BAND, band_ctrl);
> + writel(reg, dphy->regs + DPHY_BAND_CFG);
> +
> + /*
> + * Set the required power island phase 2 time. This is mandated by DPHY
> + * specs.
> + */
> + reg = DPHY_POWER_ISLAND_EN_DATA_VAL;
> + writel(reg, dphy->regs + DPHY_POWER_ISLAND_EN_DATA);
> + reg = DPHY_POWER_ISLAND_EN_CLK_VAL;
> + writel(reg, dphy->regs + DPHY_POWER_ISLAND_EN_CLK);
> +
> + ret = cdns_dphy_rx_wait_lane_ready(dphy, opts->mipi_dphy.lanes);
> + if (ret) {
> + dev_err(dphy->dev, "DPHY wait for lane ready timeout\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int cdns_dphy_rx_validate(struct phy *phy, enum phy_mode mode,
> + int submode, union phy_configure_opts *opts)
> +{
> + int ret;
> +
> + if (mode != PHY_MODE_MIPI_DPHY)
> + return -EINVAL;
> +
> + ret = cdns_dphy_rx_get_band_ctrl(opts->mipi_dphy.hs_clk_rate);
> + if (ret < 0)
> + return ret;
> +
> + return phy_mipi_dphy_config_validate(&opts->mipi_dphy);
> +}
> +
> +static const struct phy_ops cdns_dphy_rx_ops = {
> + .power_on = cdns_dphy_rx_power_on,
> + .power_off = cdns_dphy_rx_power_off,
> + .configure = cdns_dphy_rx_configure,
> + .validate = cdns_dphy_rx_validate,
> +};
> +
> +static int cdns_dphy_rx_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct phy_provider *provider;
> + struct cdns_dphy_rx *dphy;
> +
> + dphy = devm_kzalloc(dev, sizeof(*dphy), GFP_KERNEL);
> + if (!dphy)
> + return -ENOMEM;
> +
> + dev_set_drvdata(dev, dphy);
> + dphy->dev = dev;
> +
> + dphy->regs = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(dphy->regs))
> + return PTR_ERR(dphy->regs);
> +
> + dphy->phy = devm_phy_create(dev, NULL, &cdns_dphy_rx_ops);
> + if (IS_ERR(dphy->phy)) {
> + dev_err(dev, "Failed to create PHY: %d\n", PTR_ERR(dphy->phy));
> + return PTR_ERR(dphy->phy);
> + }
> +
> + phy_set_drvdata(dphy->phy, dphy);
> + provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
> + if (IS_ERR(provider)) {
> + dev_err(dev, "Failed to register PHY provider: %d\n",
> + PTR_ERR(provider));
> + return PTR_ERR(provider);
> + }
> +
> + return 0;
> +}
> +
> +static const struct of_device_id cdns_dphy_rx_of_match[] = {
> + { .compatible = "cdns,dphy-rx" },
> + { /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, cdns_dphy_rx_of_match);
> +
> +static struct platform_driver cdns_dphy_rx_platform_driver = {
> + .probe = cdns_dphy_rx_probe,
> + .driver = {
> + .name = "cdns-mipi-dphy-rx",
> + .of_match_table = cdns_dphy_rx_of_match,
> + },
> +};
> +module_platform_driver(cdns_dphy_rx_platform_driver);
> +
> +MODULE_AUTHOR("Pratyush Yadav <[email protected]>");
> +MODULE_DESCRIPTION("Cadence D-PHY Rx Driver");
> +MODULE_LICENSE("GPL v2");

This should be "GPL". "GPL v2" exists for historical reasons (see
Documentation/process/license-rules.rst).

Reviewed-by: Laurent Pinchart <[email protected]>

--
Regards,

Laurent Pinchart

2021-12-31 10:29:20

by Pratyush Yadav

[permalink] [raw]
Subject: Re: [PATCH v7 1/4] phy: cadence: Add Cadence D-PHY Rx driver

On 30/12/21 01:30AM, Laurent Pinchart wrote:
> Hi Pratyush,
>
> Thank you for the patch.
>
> On Mon, Dec 27, 2021 at 04:25:42PM +0530, Pratyush Yadav wrote:
> > The Cadence D-PHY can be configured in Tx (DSI) mode or Rx (CSI) mode.
> > Both modes have a different programming sequence and share little among
> > them. In addition, a PHY configured in Tx mode cannot be used in Rx mode
> > and vice versa. For this reason, create a separate driver for the Rx
> > mode to make it easier to read and maintain.
> >
> > Signed-off-by: Pratyush Yadav <[email protected]>
> >
> > ---
> >
> > Changes in v7:
> > - Add spaces after { and before } in the bands table.
> > - Drop the wrapping around the for loop on cdns_dphy_rx_get_band_ctrl().
> > - Make cdns_dphy_rx_wait_for_bit() inline.
> > - Print an error message if registering PHY provider fails.
> >
> > Changes in v6:
> > - Move to a separate driver.
> >
> > Changes in v5:
> > - Use the new cdns_dphy_info to specify PHY ops.
> > - Re-order include in alphabetical order.
> > - Make bands const.
> > - Drop num_bands.
> > - Make i, lanes unsigned.
> > - Drop the maximum check in cdns_dphy_rx_get_band_ctrl(). Let the loop
> > complete and return -EOPNOTSUPP when we reach the end.
> > - Drop the "rate < bands[i].min_rate" check since the bands are in
> > ascending order.
> > - Move data_lane_ctrl to start of function and make it static const.
> >
> > Changes in v4:
> > - Drop the submode parts. Use a different compatible for the Rx ops.
> > - Make bands and num_bands static.
> >
> > Changes in v3:
> > - Use a table to select the band.
> > - Use a table to poll the data lane ready bits.
> > - Multiply the DPHY HS clock rate by 2 to get the bit rate since the
> > clock is DDR.
> >
> > drivers/phy/cadence/Kconfig | 8 +
> > drivers/phy/cadence/Makefile | 1 +
> > drivers/phy/cadence/cdns-dphy-rx.c | 255 +++++++++++++++++++++++++++++
> > 3 files changed, 264 insertions(+)
> > create mode 100644 drivers/phy/cadence/cdns-dphy-rx.c
> >
> > diff --git a/drivers/phy/cadence/Kconfig b/drivers/phy/cadence/Kconfig
> > index a62910ff5591..1adde2d99ae7 100644
> > --- a/drivers/phy/cadence/Kconfig
> > +++ b/drivers/phy/cadence/Kconfig
> > @@ -22,6 +22,14 @@ config PHY_CADENCE_DPHY
> > system. If M is selected, the module will be called
> > cdns-dphy.
> >
> > +config PHY_CADENCE_DPHY_RX
> > + tristate "Cadence D-PHY Rx Support"
> > + depends on HAS_IOMEM && OF
> > + select GENERIC_PHY
> > + select GENERIC_PHY_MIPI_DPHY
> > + help
> > + Support for Cadence D-PHY in Rx configuration.
> > +
> > config PHY_CADENCE_SIERRA
> > tristate "Cadence Sierra PHY Driver"
> > depends on OF && HAS_IOMEM && RESET_CONTROLLER
> > diff --git a/drivers/phy/cadence/Makefile b/drivers/phy/cadence/Makefile
> > index 26e16bd34efe..e17f035ddece 100644
> > --- a/drivers/phy/cadence/Makefile
> > +++ b/drivers/phy/cadence/Makefile
> > @@ -1,5 +1,6 @@
> > # SPDX-License-Identifier: GPL-2.0-only
> > obj-$(CONFIG_PHY_CADENCE_TORRENT) += phy-cadence-torrent.o
> > obj-$(CONFIG_PHY_CADENCE_DPHY) += cdns-dphy.o
> > +obj-$(CONFIG_PHY_CADENCE_DPHY_RX) += cdns-dphy-rx.o
> > obj-$(CONFIG_PHY_CADENCE_SIERRA) += phy-cadence-sierra.o
> > obj-$(CONFIG_PHY_CADENCE_SALVO) += phy-cadence-salvo.o
> > diff --git a/drivers/phy/cadence/cdns-dphy-rx.c b/drivers/phy/cadence/cdns-dphy-rx.c
> > new file mode 100644
> > index 000000000000..47a5b67ded58
> > --- /dev/null
> > +++ b/drivers/phy/cadence/cdns-dphy-rx.c
> > @@ -0,0 +1,255 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Copyright (C) 2021 Texas Instruments Incorporated - https://www.ti.com/
> > + */
> > +
> > +#include <linux/bitfield.h>
> > +#include <linux/bitops.h>
> > +#include <linux/io.h>
> > +#include <linux/iopoll.h>
> > +#include <linux/module.h>
> > +#include <linux/phy/phy.h>
> > +#include <linux/phy/phy-mipi-dphy.h>
> > +#include <linux/platform_device.h>
> > +
> > +#define DPHY_PMA_CMN(reg) (reg)
> > +#define DPHY_PCS(reg) (0xb00 + (reg))
> > +#define DPHY_ISO(reg) (0xc00 + (reg))
> > +
> > +#define DPHY_CMN_SSM DPHY_PMA_CMN(0x20)
> > +#define DPHY_CMN_RX_MODE_EN BIT(10)
> > +#define DPHY_CMN_RX_BANDGAP_TIMER_MASK GENMASK(8, 1)
> > +#define DPHY_CMN_SSM_EN BIT(0)
> > +
> > +#define DPHY_CMN_RX_BANDGAP_TIMER 0x14
> > +
> > +#define DPHY_BAND_CFG DPHY_PCS(0x0)
> > +#define DPHY_BAND_CFG_RIGHT_BAND GENMASK(9, 5)
> > +#define DPHY_BAND_CFG_LEFT_BAND GENMASK(4, 0)
> > +
> > +#define DPHY_POWER_ISLAND_EN_DATA DPHY_PCS(0x8)
> > +#define DPHY_POWER_ISLAND_EN_DATA_VAL 0xaaaaaaaa
> > +
> > +#define DPHY_POWER_ISLAND_EN_CLK DPHY_PCS(0xc)
> > +#define DPHY_POWER_ISLAND_EN_CLK_VAL 0xaa
> > +
> > +#define DPHY_ISO_CL_CTRL_L DPHY_ISO(0x10)
> > +#define DPHY_ISO_DL_CTRL_L0 DPHY_ISO(0x14)
> > +#define DPHY_ISO_DL_CTRL_L1 DPHY_ISO(0x20)
> > +#define DPHY_ISO_DL_CTRL_L2 DPHY_ISO(0x30)
> > +#define DPHY_ISO_DL_CTRL_L3 DPHY_ISO(0x3c)
> > +
> > +#define DPHY_ISO_LANE_READY_BIT 0
> > +#define DPHY_ISO_LANE_READY_TIMEOUT_MS 100UL
> > +
> > +#define DPHY_LANES_MIN 1
> > +#define DPHY_LANES_MAX 4
> > +
> > +struct cdns_dphy_rx {
> > + void __iomem *regs;
> > + struct device *dev;
> > + struct phy *phy;
> > +};
> > +
> > +struct cdns_dphy_rx_band {
> > + /* Rates are in Mbps. */
> > + unsigned int min_rate;
> > + unsigned int max_rate;
> > +};
> > +
> > +/* Order of bands is important since the index is the band number. */
> > +static const struct cdns_dphy_rx_band bands[] = {
> > + { 80, 100 }, { 100, 120 }, { 120, 160 }, { 160, 200 }, { 200, 240 },
> > + { 240, 280 }, { 280, 320 }, { 320, 360 }, { 360, 400 }, { 400, 480 },
> > + { 480, 560 }, { 560, 640 }, { 640, 720 }, { 720, 800 }, { 800, 880 },
> > + { 880, 1040 }, { 1040, 1200 }, { 1200, 1350 }, { 1350, 1500 },
> > + { 1500, 1750 }, { 1750, 2000 }, { 2000, 2250 }, { 2250, 2500 }
>
> It could be possible to store only the min or max rate, as
> bands[i].max_rate == bands[i+1].min_rate. Up to you.

I don't have a strong preference. I think this looks a bit nicer and is
easier to understand at first glance.

>
> > +};
> > +
> > +static int cdns_dphy_rx_power_on(struct phy *phy)
> > +{
> > + struct cdns_dphy_rx *dphy = phy_get_drvdata(phy);
> > +
> > + /* Start RX state machine. */
> > + writel(DPHY_CMN_SSM_EN | DPHY_CMN_RX_MODE_EN |
> > + FIELD_PREP(DPHY_CMN_RX_BANDGAP_TIMER_MASK,
> > + DPHY_CMN_RX_BANDGAP_TIMER),
> > + dphy->regs + DPHY_CMN_SSM);
> > +
> > + return 0;
> > +}
> > +
> > +static int cdns_dphy_rx_power_off(struct phy *phy)
> > +{
> > + struct cdns_dphy_rx *dphy = phy_get_drvdata(phy);
> > +
> > + writel(0, dphy->regs + DPHY_CMN_SSM);
> > +
> > + return 0;
> > +}
> > +
> > +static int cdns_dphy_rx_get_band_ctrl(unsigned long hs_clk_rate)
> > +{
> > + unsigned int rate, i;
> > +
> > + rate = hs_clk_rate / 1000000UL;
> > + /* Since CSI-2 clock is DDR, the bit rate is twice the clock rate. */
> > + rate *= 2;
> > +
> > + if (rate < bands[0].min_rate)
> > + return -EOPNOTSUPP;
> > +
> > + for (i = 0; i < ARRAY_SIZE(bands); i++)
> > + if (rate < bands[i].max_rate)
> > + return i;
> > +
> > + return -EOPNOTSUPP;
> > +}
> > +
> > +static inline int cdns_dphy_rx_wait_for_bit(void __iomem *addr,
> > + unsigned int bit)
> > +{
> > + u32 val;
> > +
> > + return readl_relaxed_poll_timeout(addr, val, val & BIT(bit), 10,
> > + DPHY_ISO_LANE_READY_TIMEOUT_MS * 1000);
> > +}
> > +
> > +static int cdns_dphy_rx_wait_lane_ready(struct cdns_dphy_rx *dphy,
> > + unsigned int lanes)
> > +{
> > + static const u32 data_lane_ctrl[] = {DPHY_ISO_DL_CTRL_L0,
> > + DPHY_ISO_DL_CTRL_L1,
> > + DPHY_ISO_DL_CTRL_L2,
> > + DPHY_ISO_DL_CTRL_L3};
> > + void __iomem *reg = dphy->regs;
> > + unsigned int i;
> > + int ret;
> > +
> > + /* Data lanes. Minimum one lane is mandatory. */
> > + if (lanes < DPHY_LANES_MIN || lanes > DPHY_LANES_MAX)
> > + return -EINVAL;
>
> How about moving this at the beginning of cdns_dphy_rx_configure(), to
> avoid starting the configuration sequence if the parameter is wrong ?

Ok.

>
> > +
> > + /* Clock lane */
> > + ret = cdns_dphy_rx_wait_for_bit(reg + DPHY_ISO_CL_CTRL_L,
> > + DPHY_ISO_LANE_READY_BIT);
> > + if (ret)
> > + return ret;
> > +
> > + for (i = 0; i < lanes; i++) {
> > + ret = cdns_dphy_rx_wait_for_bit(reg + data_lane_ctrl[i],
> > + DPHY_ISO_LANE_READY_BIT);
> > + if (ret)
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int cdns_dphy_rx_configure(struct phy *phy,
> > + union phy_configure_opts *opts)
> > +{
> > + struct cdns_dphy_rx *dphy = phy_get_drvdata(phy);
> > + unsigned int reg;
> > + int band_ctrl, ret;
> > +
> > + band_ctrl = cdns_dphy_rx_get_band_ctrl(opts->mipi_dphy.hs_clk_rate);
> > + if (band_ctrl < 0)
> > + return band_ctrl;
> > +
> > + reg = FIELD_PREP(DPHY_BAND_CFG_LEFT_BAND, band_ctrl) |
> > + FIELD_PREP(DPHY_BAND_CFG_RIGHT_BAND, band_ctrl);
> > + writel(reg, dphy->regs + DPHY_BAND_CFG);
> > +
> > + /*
> > + * Set the required power island phase 2 time. This is mandated by DPHY
> > + * specs.
> > + */
> > + reg = DPHY_POWER_ISLAND_EN_DATA_VAL;
> > + writel(reg, dphy->regs + DPHY_POWER_ISLAND_EN_DATA);
> > + reg = DPHY_POWER_ISLAND_EN_CLK_VAL;
> > + writel(reg, dphy->regs + DPHY_POWER_ISLAND_EN_CLK);
> > +
> > + ret = cdns_dphy_rx_wait_lane_ready(dphy, opts->mipi_dphy.lanes);
> > + if (ret) {
> > + dev_err(dphy->dev, "DPHY wait for lane ready timeout\n");
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int cdns_dphy_rx_validate(struct phy *phy, enum phy_mode mode,
> > + int submode, union phy_configure_opts *opts)
> > +{
> > + int ret;
> > +
> > + if (mode != PHY_MODE_MIPI_DPHY)
> > + return -EINVAL;
> > +
> > + ret = cdns_dphy_rx_get_band_ctrl(opts->mipi_dphy.hs_clk_rate);
> > + if (ret < 0)
> > + return ret;
> > +
> > + return phy_mipi_dphy_config_validate(&opts->mipi_dphy);
> > +}
> > +
> > +static const struct phy_ops cdns_dphy_rx_ops = {
> > + .power_on = cdns_dphy_rx_power_on,
> > + .power_off = cdns_dphy_rx_power_off,
> > + .configure = cdns_dphy_rx_configure,
> > + .validate = cdns_dphy_rx_validate,
> > +};
> > +
> > +static int cdns_dphy_rx_probe(struct platform_device *pdev)
> > +{
> > + struct device *dev = &pdev->dev;
> > + struct phy_provider *provider;
> > + struct cdns_dphy_rx *dphy;
> > +
> > + dphy = devm_kzalloc(dev, sizeof(*dphy), GFP_KERNEL);
> > + if (!dphy)
> > + return -ENOMEM;
> > +
> > + dev_set_drvdata(dev, dphy);
> > + dphy->dev = dev;
> > +
> > + dphy->regs = devm_platform_ioremap_resource(pdev, 0);
> > + if (IS_ERR(dphy->regs))
> > + return PTR_ERR(dphy->regs);
> > +
> > + dphy->phy = devm_phy_create(dev, NULL, &cdns_dphy_rx_ops);
> > + if (IS_ERR(dphy->phy)) {
> > + dev_err(dev, "Failed to create PHY: %d\n", PTR_ERR(dphy->phy));
> > + return PTR_ERR(dphy->phy);
> > + }
> > +
> > + phy_set_drvdata(dphy->phy, dphy);
> > + provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
> > + if (IS_ERR(provider)) {
> > + dev_err(dev, "Failed to register PHY provider: %d\n",
> > + PTR_ERR(provider));
> > + return PTR_ERR(provider);
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static const struct of_device_id cdns_dphy_rx_of_match[] = {
> > + { .compatible = "cdns,dphy-rx" },
> > + { /* sentinel */ },
> > +};
> > +MODULE_DEVICE_TABLE(of, cdns_dphy_rx_of_match);
> > +
> > +static struct platform_driver cdns_dphy_rx_platform_driver = {
> > + .probe = cdns_dphy_rx_probe,
> > + .driver = {
> > + .name = "cdns-mipi-dphy-rx",
> > + .of_match_table = cdns_dphy_rx_of_match,
> > + },
> > +};
> > +module_platform_driver(cdns_dphy_rx_platform_driver);
> > +
> > +MODULE_AUTHOR("Pratyush Yadav <[email protected]>");
> > +MODULE_DESCRIPTION("Cadence D-PHY Rx Driver");
> > +MODULE_LICENSE("GPL v2");
>
> This should be "GPL". "GPL v2" exists for historical reasons (see
> Documentation/process/license-rules.rst).

Ok.

>
> Reviewed-by: Laurent Pinchart <[email protected]>

Thanks.

--
Regards,
Pratyush Yadav
Texas Instruments Inc.