Messages in this thread Patch in this message | | | From | Pratyush Yadav <> | Subject | [PATCH v5 2/6] phy: cdns-dphy: Add Rx support | Date | Fri, 3 Sep 2021 00:25:39 +0530 |
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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 mode in which the DPHY has to be used is selected based on the compatible.
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
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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/cdns-dphy.c | 182 ++++++++++++++++++++++++++++++++ 1 file changed, 182 insertions(+)
diff --git a/drivers/phy/cadence/cdns-dphy.c b/drivers/phy/cadence/cdns-dphy.c index e2c2b27c6539..9a4c1c684e9a 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/bitfield.h> #include <linux/bitops.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; @@ -105,6 +132,20 @@ struct cdns_dphy { struct phy *phy; }; +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. */ +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_dsi_get_dphy_pll_cfg(struct cdns_dphy *dphy, struct cdns_dphy_cfg *cfg, struct phy_configure_opts_mipi_dphy *opts, @@ -360,6 +401,145 @@ static const struct cdns_dphy_info tx_ref_info = { .tx_ops = &tx_ref_dphy_ops, }; +static int cdns_dphy_rx_power_on(struct phy *phy) +{ + struct cdns_dphy *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 *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 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, + 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 *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 rx_ref_phy_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 const struct cdns_dphy_info rx_ref_info = { + .phy_ops = &rx_ref_phy_ops, +}; + static int cdns_dphy_probe(struct platform_device *pdev) { struct phy_provider *phy_provider; @@ -417,6 +597,7 @@ static int cdns_dphy_remove(struct platform_device *pdev) static const struct of_device_id cdns_dphy_of_match[] = { { .compatible = "cdns,dphy", .data = &tx_ref_info }, + { .compatible = "cdns,dphy-rx", .data = &rx_ref_info }, { /* sentinel */ }, }; MODULE_DEVICE_TABLE(of, cdns_dphy_of_match); @@ -432,5 +613,6 @@ static struct platform_driver cdns_dphy_platform_driver = { module_platform_driver(cdns_dphy_platform_driver); MODULE_AUTHOR("Maxime Ripard <maxime.ripard@bootlin.com>"); +MODULE_AUTHOR("Pratyush Yadav <p.yadav@ti.com>"); MODULE_DESCRIPTION("Cadence MIPI D-PHY Driver"); MODULE_LICENSE("GPL"); -- 2.33.0
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