diff options
Diffstat (limited to 'drivers/phy/cadence/cdns-dphy-rx.c')
| -rw-r--r-- | drivers/phy/cadence/cdns-dphy-rx.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/drivers/phy/cadence/cdns-dphy-rx.c b/drivers/phy/cadence/cdns-dphy-rx.c new file mode 100644 index 000000000..572c70089 --- /dev/null +++ b/drivers/phy/cadence/cdns-dphy-rx.c @@ -0,0 +1,255 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2022 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; + + /* 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, lanes = opts->mipi_dphy.lanes; + int band_ctrl, ret; + + /* Data lanes. Minimum one lane is mandatory. */ + if (lanes < DPHY_LANES_MIN || lanes > DPHY_LANES_MAX) + return -EINVAL; + + 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, 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: %ld\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: %ld\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 <p.yadav@ti.com>"); +MODULE_DESCRIPTION("Cadence D-PHY Rx Driver"); +MODULE_LICENSE("GPL"); |