2021-06-24 18:42:35

by Pratyush Yadav

[permalink] [raw]
Subject: [PATCH v3 0/7] Rx mode support for Cadence DPHY

Hi,

This series adds support for Rx mode on Cadence DPHY driver. It has been
split off from [0] to facilitate easier merging. I have still kept it as
v3 to maintain continuity with the previous patches. This series also
includes conversion to YAML binding.

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 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.
- Re-order subject prefixes.
- Add power-domain to the example.
- Add Laurent's R-by.
- Re-order subject prefixes.

Paul Kocialkowski (1):
phy: Distinguish between Rx and Tx for MIPI D-PHY with submodes

Pratyush Yadav (6):
phy: cdns-dphy: Prepare for Rx support
phy: cdns-dphy: Allow setting mode
phy: cdns-dphy: Add Rx support
phy: dt-bindings: Convert Cadence DPHY binding to YAML
phy: dt-bindings: cdns,dphy: make clocks optional
phy: dt-bindings: cdns,dphy: add power-domains property

.../devicetree/bindings/phy/cdns,dphy.txt | 20 -
.../devicetree/bindings/phy/cdns,dphy.yaml | 54 +++
drivers/phy/cadence/cdns-dphy.c | 344 ++++++++++++++++--
include/linux/phy/phy-mipi-dphy.h | 13 +
4 files changed, 375 insertions(+), 56 deletions(-)
delete mode 100644 Documentation/devicetree/bindings/phy/cdns,dphy.txt
create mode 100644 Documentation/devicetree/bindings/phy/cdns,dphy.yaml

--
2.30.0


2021-06-24 18:42:43

by Pratyush Yadav

[permalink] [raw]
Subject: [PATCH v3 3/7] phy: cdns-dphy: Allow setting mode

Allow callers to set the PHY mode. The main mode should always be
PHY_MODE_MIPI_DPHY but the submode can either be
PHY_MIPI_DPHY_SUBMODE_RX or PHY_MIPI_DPHY_SUBMODE_TX. Update the ops
based on the requested submode.

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

(no changes since v1)

drivers/phy/cadence/cdns-dphy.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)

diff --git a/drivers/phy/cadence/cdns-dphy.c b/drivers/phy/cadence/cdns-dphy.c
index 8656f2102a91..7d5f7b333893 100644
--- a/drivers/phy/cadence/cdns-dphy.c
+++ b/drivers/phy/cadence/cdns-dphy.c
@@ -365,11 +365,41 @@ static int cdns_dphy_configure(struct phy *phy, union phy_configure_opts *opts)
return 0;
}

+static int cdns_dphy_set_mode(struct phy *phy, enum phy_mode mode, int submode)
+{
+ struct cdns_dphy *dphy = phy_get_drvdata(phy);
+ const struct cdns_dphy_driver_data *ddata;
+
+ ddata = of_device_get_match_data(dphy->dev);
+ if (!ddata)
+ return -EINVAL;
+
+ if (mode != PHY_MODE_MIPI_DPHY)
+ return -EINVAL;
+
+ if (submode == PHY_MIPI_DPHY_SUBMODE_TX) {
+ if (!ddata->tx)
+ return -EOPNOTSUPP;
+
+ dphy->ops = ddata->tx;
+ } else if (submode == PHY_MIPI_DPHY_SUBMODE_RX) {
+ if (!ddata->rx)
+ return -EOPNOTSUPP;
+
+ dphy->ops = ddata->rx;
+ } else {
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
static const struct phy_ops cdns_dphy_ops = {
.configure = cdns_dphy_configure,
.validate = cdns_dphy_validate,
.power_on = cdns_dphy_power_on,
.power_off = cdns_dphy_power_off,
+ .set_mode = cdns_dphy_set_mode,
};

static int cdns_dphy_probe(struct platform_device *pdev)
--
2.30.0

2021-06-24 18:43:12

by Pratyush Yadav

[permalink] [raw]
Subject: [PATCH v3 7/7] phy: dt-bindings: cdns,dphy: add power-domains property

This property is needed on TI platforms to enable the PD of the DPHY
before it can be used.

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

---

Changes in v3:
- Add Rob's Ack.

Changes in v2:
- Add power-domain to the example.
- Add Laurent's R-by.
- Re-order subject prefixes.

Documentation/devicetree/bindings/phy/cdns,dphy.yaml | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/phy/cdns,dphy.yaml b/Documentation/devicetree/bindings/phy/cdns,dphy.yaml
index 3bb5be05e825..d5a5e1f0b671 100644
--- a/Documentation/devicetree/bindings/phy/cdns,dphy.yaml
+++ b/Documentation/devicetree/bindings/phy/cdns,dphy.yaml
@@ -30,6 +30,9 @@ properties:
"#phy-cells":
const: 0

+ power-domains:
+ maxItems: 1
+
required:
- compatible
- reg
@@ -39,11 +42,13 @@ additionalProperties: false

examples:
- |
+ #include <dt-bindings/soc/ti,sci_pm_domain.h>

dphy0: phy@fd0e0000{
compatible = "cdns,dphy";
reg = <0xfd0e0000 0x1000>;
clocks = <&psm_clk>, <&pll_ref_clk>;
clock-names = "psm", "pll_ref";
+ power-domains = <&k3_pds 147 TI_SCI_PD_EXCLUSIVE>;
#phy-cells = <0>;
};
--
2.30.0

2021-06-24 18:43:30

by Pratyush Yadav

[permalink] [raw]
Subject: [PATCH v3 5/7] 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]>

---

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>;
+ };
--
2.30.0

2021-06-24 18:43:59

by Pratyush Yadav

[permalink] [raw]
Subject: [PATCH v3 4/7] phy: cdns-dphy: Add Rx support

The Cadence DPHY can be used to receive image data over the CSI-2
protocol. Add support for Rx mode. The programming sequence differs from
the Tx mode so it is added as a separate set of hooks to isolate the two
paths.

The PHY is in Tx mode by default and it needs to be set in Rx mode by
setting the submode to PHY_MIPI_DPHY_SUBMODE_RX in the set_mode()
callback.

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

---

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/cdns-dphy.c | 174 ++++++++++++++++++++++++++++++++
1 file changed, 174 insertions(+)

diff --git a/drivers/phy/cadence/cdns-dphy.c b/drivers/phy/cadence/cdns-dphy.c
index 7d5f7b333893..7534ec957dc5 100644
--- a/drivers/phy/cadence/cdns-dphy.c
+++ b/drivers/phy/cadence/cdns-dphy.c
@@ -1,11 +1,14 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright: 2017-2018 Cadence Design Systems, Inc.
+ * Copyright (C) 2021 Texas Instruments Incorporated - https://www.ti.com/
*/

#include <linux/bitops.h>
+#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/io.h>
+#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
@@ -25,10 +28,14 @@
#define DPHY_PMA_RCLK(reg) (0x600 + (reg))
#define DPHY_PMA_RDATA(lane, reg) (0x700 + ((lane) * 0x100) + (reg))
#define DPHY_PCS(reg) (0xb00 + (reg))
+#define DPHY_ISO(reg) (0xc00 + (reg))

#define DPHY_CMN_SSM DPHY_PMA_CMN(0x20)
#define DPHY_CMN_SSM_EN BIT(0)
+#define DPHY_CMN_RX_BANDGAP_TIMER_MASK GENMASK(8, 1)
#define DPHY_CMN_TX_MODE_EN BIT(9)
+#define DPHY_CMN_RX_MODE_EN BIT(10)
+#define DPHY_CMN_RX_BANDGAP_TIMER 0x14

#define DPHY_CMN_PWM DPHY_PMA_CMN(0x40)
#define DPHY_CMN_PWM_DIV(x) ((x) << 20)
@@ -45,10 +52,27 @@
#define DPHY_CMN_OPDIV_FROM_REG BIT(6)
#define DPHY_CMN_OPDIV(x) ((x) << 7)

+#define DPHY_BAND_CFG DPHY_PCS(0x0)
+#define DPHY_BAND_CFG_LEFT_BAND GENMASK(4, 0)
+#define DPHY_BAND_CFG_RIGHT_BAND GENMASK(9, 5)
+
#define DPHY_PSM_CFG DPHY_PCS(0x4)
#define DPHY_PSM_CFG_FROM_REG BIT(0)
#define DPHY_PSM_CLK_DIV(x) ((x) << 1)

+#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 DSI_HBP_FRAME_OVERHEAD 12
#define DSI_HSA_FRAME_OVERHEAD 14
#define DSI_HFP_FRAME_OVERHEAD 6
@@ -57,6 +81,9 @@
#define DSI_NULL_FRAME_OVERHEAD 6
#define DSI_EOT_PKT_SIZE 4

+#define DPHY_LANES_MIN 1
+#define DPHY_LANES_MAX 4
+
struct cdns_dphy_cfg {
u8 pll_ipdiv;
u8 pll_opdiv;
@@ -103,6 +130,22 @@ struct cdns_dphy_driver_data {
const struct cdns_dphy_ops *rx;
};

+struct cdns_dphy_rx_band {
+ unsigned int min_rate;
+ unsigned int max_rate;
+};
+
+/* Order of bands is important since the index is the band number. */
+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}
+};
+
+int num_bands = ARRAY_SIZE(bands);
+
static int cdns_dsi_get_dphy_pll_cfg(struct cdns_dphy *dphy,
struct cdns_dphy_cfg *cfg,
struct phy_configure_opts_mipi_dphy *opts,
@@ -312,6 +355,135 @@ static const struct cdns_dphy_ops tx_ref_dphy_ops = {
.set_psm_div = cdns_dphy_ref_set_psm_div,
};

+static int cdns_dphy_rx_power_on(struct cdns_dphy *dphy)
+{
+ /* 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 cdns_dphy *dphy)
+{
+ 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;
+ int 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 || rate >= bands[num_bands - 1].max_rate)
+ return -EOPNOTSUPP;
+
+ for (i = 0; i < num_bands; i++) {
+ if (rate >= bands[i].min_rate && rate < bands[i].max_rate)
+ return i;
+ }
+
+ /* Unreachable. */
+ WARN(1, "Reached unreachable code.");
+ return -EINVAL;
+}
+
+static 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 *dphy, int lanes)
+{
+ void __iomem *reg = dphy->regs;
+ u32 data_lane_ctrl[] = {DPHY_ISO_DL_CTRL_L0, DPHY_ISO_DL_CTRL_L1,
+ DPHY_ISO_DL_CTRL_L2, DPHY_ISO_DL_CTRL_L3};
+ int ret, i;
+
+ /* 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 cdns_dphy *dphy,
+ union phy_configure_opts *opts)
+{
+ 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 cdns_dphy *dphy, enum phy_mode mode,
+ int submode, union phy_configure_opts *opts)
+{
+ int ret;
+
+ if (submode != PHY_MIPI_DPHY_SUBMODE_RX)
+ 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 cdns_dphy_ops rx_ref_dphy_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,
+};
+
/*
* This is the reference implementation of DPHY hooks. Specific integration of
* this IP may have to re-implement some of them depending on how they decided
@@ -319,6 +491,7 @@ static const struct cdns_dphy_ops tx_ref_dphy_ops = {
*/
static const struct cdns_dphy_driver_data ref_dphy_ops = {
.tx = &tx_ref_dphy_ops,
+ .rx = &rx_ref_dphy_ops,
};

static int cdns_dphy_validate(struct phy *phy, enum phy_mode mode, int submode,
@@ -483,5 +656,6 @@ static struct platform_driver cdns_dphy_platform_driver = {
module_platform_driver(cdns_dphy_platform_driver);

MODULE_AUTHOR("Maxime Ripard <[email protected]>");
+MODULE_AUTHOR("Pratyush Yadav <[email protected]>");
MODULE_DESCRIPTION("Cadence MIPI D-PHY Driver");
MODULE_LICENSE("GPL");
--
2.30.0

2021-06-24 18:44:15

by Pratyush Yadav

[permalink] [raw]
Subject: [PATCH v3 6/7] phy: dt-bindings: cdns,dphy: make clocks optional

The clocks are not used by the DPHY when used in Rx mode so make them
optional.

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

---

Changes in v3:
- Add Rob's Ack.

Changes in v2:
- Re-order subject prefixes.

Documentation/devicetree/bindings/phy/cdns,dphy.yaml | 2 --
1 file changed, 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/phy/cdns,dphy.yaml b/Documentation/devicetree/bindings/phy/cdns,dphy.yaml
index b90a58773bf2..3bb5be05e825 100644
--- a/Documentation/devicetree/bindings/phy/cdns,dphy.yaml
+++ b/Documentation/devicetree/bindings/phy/cdns,dphy.yaml
@@ -33,8 +33,6 @@ properties:
required:
- compatible
- reg
- - clocks
- - clock-names
- "#phy-cells"

additionalProperties: false
--
2.30.0

2021-08-06 16:55:04

by Vinod Koul

[permalink] [raw]
Subject: Re: [PATCH v3 4/7] phy: cdns-dphy: Add Rx support

On 25-06-21, 00:11, Pratyush Yadav wrote:
> The Cadence DPHY can be used to receive image data over the CSI-2
> protocol. Add support for Rx mode. The programming sequence differs from
> the Tx mode so it is added as a separate set of hooks to isolate the two
> paths.
>
> The PHY is in Tx mode by default and it needs to be set in Rx mode by
> setting the submode to PHY_MIPI_DPHY_SUBMODE_RX in the set_mode()
> callback.
>
> Signed-off-by: Pratyush Yadav <[email protected]>
>
> ---
>
> 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/cdns-dphy.c | 174 ++++++++++++++++++++++++++++++++
> 1 file changed, 174 insertions(+)
>
> diff --git a/drivers/phy/cadence/cdns-dphy.c b/drivers/phy/cadence/cdns-dphy.c
> index 7d5f7b333893..7534ec957dc5 100644
> --- a/drivers/phy/cadence/cdns-dphy.c
> +++ b/drivers/phy/cadence/cdns-dphy.c
> @@ -1,11 +1,14 @@
> // SPDX-License-Identifier: GPL-2.0+
> /*
> * Copyright: 2017-2018 Cadence Design Systems, Inc.
> + * Copyright (C) 2021 Texas Instruments Incorporated - https://www.ti.com/
> */
>
> #include <linux/bitops.h>
> +#include <linux/bitfield.h>
> #include <linux/clk.h>
> #include <linux/io.h>
> +#include <linux/iopoll.h>
> #include <linux/module.h>
> #include <linux/of_address.h>
> #include <linux/of_device.h>
> @@ -25,10 +28,14 @@
> #define DPHY_PMA_RCLK(reg) (0x600 + (reg))
> #define DPHY_PMA_RDATA(lane, reg) (0x700 + ((lane) * 0x100) + (reg))
> #define DPHY_PCS(reg) (0xb00 + (reg))
> +#define DPHY_ISO(reg) (0xc00 + (reg))
>
> #define DPHY_CMN_SSM DPHY_PMA_CMN(0x20)
> #define DPHY_CMN_SSM_EN BIT(0)
> +#define DPHY_CMN_RX_BANDGAP_TIMER_MASK GENMASK(8, 1)
> #define DPHY_CMN_TX_MODE_EN BIT(9)
> +#define DPHY_CMN_RX_MODE_EN BIT(10)
> +#define DPHY_CMN_RX_BANDGAP_TIMER 0x14
>
> #define DPHY_CMN_PWM DPHY_PMA_CMN(0x40)
> #define DPHY_CMN_PWM_DIV(x) ((x) << 20)
> @@ -45,10 +52,27 @@
> #define DPHY_CMN_OPDIV_FROM_REG BIT(6)
> #define DPHY_CMN_OPDIV(x) ((x) << 7)
>
> +#define DPHY_BAND_CFG DPHY_PCS(0x0)
> +#define DPHY_BAND_CFG_LEFT_BAND GENMASK(4, 0)
> +#define DPHY_BAND_CFG_RIGHT_BAND GENMASK(9, 5)
> +
> #define DPHY_PSM_CFG DPHY_PCS(0x4)
> #define DPHY_PSM_CFG_FROM_REG BIT(0)
> #define DPHY_PSM_CLK_DIV(x) ((x) << 1)
>
> +#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 DSI_HBP_FRAME_OVERHEAD 12
> #define DSI_HSA_FRAME_OVERHEAD 14
> #define DSI_HFP_FRAME_OVERHEAD 6
> @@ -57,6 +81,9 @@
> #define DSI_NULL_FRAME_OVERHEAD 6
> #define DSI_EOT_PKT_SIZE 4
>
> +#define DPHY_LANES_MIN 1
> +#define DPHY_LANES_MAX 4
> +
> struct cdns_dphy_cfg {
> u8 pll_ipdiv;
> u8 pll_opdiv;
> @@ -103,6 +130,22 @@ struct cdns_dphy_driver_data {
> const struct cdns_dphy_ops *rx;
> };
>
> +struct cdns_dphy_rx_band {
> + unsigned int min_rate;
> + unsigned int max_rate;
> +};
> +
> +/* Order of bands is important since the index is the band number. */
> +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}
> +};
> +
> +int num_bands = ARRAY_SIZE(bands);
> +
> static int cdns_dsi_get_dphy_pll_cfg(struct cdns_dphy *dphy,
> struct cdns_dphy_cfg *cfg,
> struct phy_configure_opts_mipi_dphy *opts,
> @@ -312,6 +355,135 @@ static const struct cdns_dphy_ops tx_ref_dphy_ops = {
> .set_psm_div = cdns_dphy_ref_set_psm_div,
> };
>
> +static int cdns_dphy_rx_power_on(struct cdns_dphy *dphy)
> +{
> + /* 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 cdns_dphy *dphy)
> +{
> + 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;
> + int 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 || rate >= bands[num_bands - 1].max_rate)
> + return -EOPNOTSUPP;
> +
> + for (i = 0; i < num_bands; i++) {
> + if (rate >= bands[i].min_rate && rate < bands[i].max_rate)
> + return i;
> + }
> +
> + /* Unreachable. */
> + WARN(1, "Reached unreachable code.");
> + return -EINVAL;
> +}
> +
> +static 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);

this looks wrong, val is not initialized, so what/when is condition to
be met..?
--
~Vinod

2021-08-11 17:40:56

by Pratyush Yadav

[permalink] [raw]
Subject: Re: [PATCH v3 4/7] phy: cdns-dphy: Add Rx support

On 06/08/21 04:45PM, Vinod Koul wrote:
> On 25-06-21, 00:11, Pratyush Yadav wrote:
> > The Cadence DPHY can be used to receive image data over the CSI-2
> > protocol. Add support for Rx mode. The programming sequence differs from
> > the Tx mode so it is added as a separate set of hooks to isolate the two
> > paths.
> >
> > The PHY is in Tx mode by default and it needs to be set in Rx mode by
> > setting the submode to PHY_MIPI_DPHY_SUBMODE_RX in the set_mode()
> > callback.
> >
> > Signed-off-by: Pratyush Yadav <[email protected]>
> >
> > ---
> >
> > 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/cdns-dphy.c | 174 ++++++++++++++++++++++++++++++++
> > 1 file changed, 174 insertions(+)
> >
> > diff --git a/drivers/phy/cadence/cdns-dphy.c b/drivers/phy/cadence/cdns-dphy.c
> > index 7d5f7b333893..7534ec957dc5 100644
> > --- a/drivers/phy/cadence/cdns-dphy.c
> > +++ b/drivers/phy/cadence/cdns-dphy.c
> > @@ -1,11 +1,14 @@
> > // SPDX-License-Identifier: GPL-2.0+
> > /*
> > * Copyright: 2017-2018 Cadence Design Systems, Inc.
> > + * Copyright (C) 2021 Texas Instruments Incorporated - https://www.ti.com/
> > */
> >
> > #include <linux/bitops.h>
> > +#include <linux/bitfield.h>
> > #include <linux/clk.h>
> > #include <linux/io.h>
> > +#include <linux/iopoll.h>
> > #include <linux/module.h>
> > #include <linux/of_address.h>
> > #include <linux/of_device.h>
> > @@ -25,10 +28,14 @@
> > #define DPHY_PMA_RCLK(reg) (0x600 + (reg))
> > #define DPHY_PMA_RDATA(lane, reg) (0x700 + ((lane) * 0x100) + (reg))
> > #define DPHY_PCS(reg) (0xb00 + (reg))
> > +#define DPHY_ISO(reg) (0xc00 + (reg))
> >
> > #define DPHY_CMN_SSM DPHY_PMA_CMN(0x20)
> > #define DPHY_CMN_SSM_EN BIT(0)
> > +#define DPHY_CMN_RX_BANDGAP_TIMER_MASK GENMASK(8, 1)
> > #define DPHY_CMN_TX_MODE_EN BIT(9)
> > +#define DPHY_CMN_RX_MODE_EN BIT(10)
> > +#define DPHY_CMN_RX_BANDGAP_TIMER 0x14
> >
> > #define DPHY_CMN_PWM DPHY_PMA_CMN(0x40)
> > #define DPHY_CMN_PWM_DIV(x) ((x) << 20)
> > @@ -45,10 +52,27 @@
> > #define DPHY_CMN_OPDIV_FROM_REG BIT(6)
> > #define DPHY_CMN_OPDIV(x) ((x) << 7)
> >
> > +#define DPHY_BAND_CFG DPHY_PCS(0x0)
> > +#define DPHY_BAND_CFG_LEFT_BAND GENMASK(4, 0)
> > +#define DPHY_BAND_CFG_RIGHT_BAND GENMASK(9, 5)
> > +
> > #define DPHY_PSM_CFG DPHY_PCS(0x4)
> > #define DPHY_PSM_CFG_FROM_REG BIT(0)
> > #define DPHY_PSM_CLK_DIV(x) ((x) << 1)
> >
> > +#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 DSI_HBP_FRAME_OVERHEAD 12
> > #define DSI_HSA_FRAME_OVERHEAD 14
> > #define DSI_HFP_FRAME_OVERHEAD 6
> > @@ -57,6 +81,9 @@
> > #define DSI_NULL_FRAME_OVERHEAD 6
> > #define DSI_EOT_PKT_SIZE 4
> >
> > +#define DPHY_LANES_MIN 1
> > +#define DPHY_LANES_MAX 4
> > +
> > struct cdns_dphy_cfg {
> > u8 pll_ipdiv;
> > u8 pll_opdiv;
> > @@ -103,6 +130,22 @@ struct cdns_dphy_driver_data {
> > const struct cdns_dphy_ops *rx;
> > };
> >
> > +struct cdns_dphy_rx_band {
> > + unsigned int min_rate;
> > + unsigned int max_rate;
> > +};
> > +
> > +/* Order of bands is important since the index is the band number. */
> > +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}
> > +};
> > +
> > +int num_bands = ARRAY_SIZE(bands);
> > +
> > static int cdns_dsi_get_dphy_pll_cfg(struct cdns_dphy *dphy,
> > struct cdns_dphy_cfg *cfg,
> > struct phy_configure_opts_mipi_dphy *opts,
> > @@ -312,6 +355,135 @@ static const struct cdns_dphy_ops tx_ref_dphy_ops = {
> > .set_psm_div = cdns_dphy_ref_set_psm_div,
> > };
> >
> > +static int cdns_dphy_rx_power_on(struct cdns_dphy *dphy)
> > +{
> > + /* 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 cdns_dphy *dphy)
> > +{
> > + 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;
> > + int 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 || rate >= bands[num_bands - 1].max_rate)
> > + return -EOPNOTSUPP;
> > +
> > + for (i = 0; i < num_bands; i++) {
> > + if (rate >= bands[i].min_rate && rate < bands[i].max_rate)
> > + return i;
> > + }
> > +
> > + /* Unreachable. */
> > + WARN(1, "Reached unreachable code.");
> > + return -EINVAL;
> > +}
> > +
> > +static 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);
>
> this looks wrong, val is not initialized, so what/when is condition to
> be met..?

The readl_relaxed_poll_timeout() macro puts the value returned by
readl() into val. That value is then used for testing the condition. See
read_poll_timeout() in iopoll.h to see what the macro eventually expands
to.

> --
> ~Vinod

--
Regards,
Pratyush Yadav
Texas Instruments Inc.