diff options
Diffstat (limited to 'drivers/phy/cadence/cdns-dphy.c')
| -rw-r--r-- | drivers/phy/cadence/cdns-dphy.c | 391 |
1 files changed, 391 insertions, 0 deletions
diff --git a/drivers/phy/cadence/cdns-dphy.c b/drivers/phy/cadence/cdns-dphy.c new file mode 100644 index 000000000000..90c4e9b5aac8 --- /dev/null +++ b/drivers/phy/cadence/cdns-dphy.c @@ -0,0 +1,391 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright: 2017-2018 Cadence Design Systems, Inc. + */ + +#include <linux/bitops.h> +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/reset.h> + +#include <linux/phy/phy.h> +#include <linux/phy/phy-mipi-dphy.h> + +#define REG_WAKEUP_TIME_NS 800 +#define DPHY_PLL_RATE_HZ 108000000 + +/* DPHY registers */ +#define DPHY_PMA_CMN(reg) (reg) +#define DPHY_PMA_LCLK(reg) (0x100 + (reg)) +#define DPHY_PMA_LDATA(lane, reg) (0x200 + ((lane) * 0x100) + (reg)) +#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_CMN_SSM DPHY_PMA_CMN(0x20) +#define DPHY_CMN_SSM_EN BIT(0) +#define DPHY_CMN_TX_MODE_EN BIT(9) + +#define DPHY_CMN_PWM DPHY_PMA_CMN(0x40) +#define DPHY_CMN_PWM_DIV(x) ((x) << 20) +#define DPHY_CMN_PWM_LOW(x) ((x) << 10) +#define DPHY_CMN_PWM_HIGH(x) (x) + +#define DPHY_CMN_FBDIV DPHY_PMA_CMN(0x4c) +#define DPHY_CMN_FBDIV_VAL(low, high) (((high) << 11) | ((low) << 22)) +#define DPHY_CMN_FBDIV_FROM_REG (BIT(10) | BIT(21)) + +#define DPHY_CMN_OPIPDIV DPHY_PMA_CMN(0x50) +#define DPHY_CMN_IPDIV_FROM_REG BIT(0) +#define DPHY_CMN_IPDIV(x) ((x) << 1) +#define DPHY_CMN_OPDIV_FROM_REG BIT(6) +#define DPHY_CMN_OPDIV(x) ((x) << 7) + +#define DPHY_PSM_CFG DPHY_PCS(0x4) +#define DPHY_PSM_CFG_FROM_REG BIT(0) +#define DPHY_PSM_CLK_DIV(x) ((x) << 1) + +#define DSI_HBP_FRAME_OVERHEAD 12 +#define DSI_HSA_FRAME_OVERHEAD 14 +#define DSI_HFP_FRAME_OVERHEAD 6 +#define DSI_HSS_VSS_VSE_FRAME_OVERHEAD 4 +#define DSI_BLANKING_FRAME_OVERHEAD 6 +#define DSI_NULL_FRAME_OVERHEAD 6 +#define DSI_EOT_PKT_SIZE 4 + +struct cdns_dphy_cfg { + u8 pll_ipdiv; + u8 pll_opdiv; + u16 pll_fbdiv; + unsigned int nlanes; +}; + +enum cdns_dphy_clk_lane_cfg { + DPHY_CLK_CFG_LEFT_DRIVES_ALL = 0, + DPHY_CLK_CFG_LEFT_DRIVES_RIGHT = 1, + DPHY_CLK_CFG_LEFT_DRIVES_LEFT = 2, + DPHY_CLK_CFG_RIGHT_DRIVES_ALL = 3, +}; + +struct cdns_dphy; +struct cdns_dphy_ops { + int (*probe)(struct cdns_dphy *dphy); + void (*remove)(struct cdns_dphy *dphy); + void (*set_psm_div)(struct cdns_dphy *dphy, u8 div); + void (*set_clk_lane_cfg)(struct cdns_dphy *dphy, + enum cdns_dphy_clk_lane_cfg cfg); + void (*set_pll_cfg)(struct cdns_dphy *dphy, + const struct cdns_dphy_cfg *cfg); + unsigned long (*get_wakeup_time_ns)(struct cdns_dphy *dphy); +}; + +struct cdns_dphy { + struct cdns_dphy_cfg cfg; + void __iomem *regs; + struct clk *psm_clk; + struct clk *pll_ref_clk; + const struct cdns_dphy_ops *ops; + struct phy *phy; +}; + +static int cdns_dsi_get_dphy_pll_cfg(struct cdns_dphy *dphy, + struct cdns_dphy_cfg *cfg, + struct phy_configure_opts_mipi_dphy *opts, + unsigned int *dsi_hfp_ext) +{ + unsigned long pll_ref_hz = clk_get_rate(dphy->pll_ref_clk); + u64 dlane_bps; + + memset(cfg, 0, sizeof(*cfg)); + + if (pll_ref_hz < 9600000 || pll_ref_hz >= 150000000) + return -EINVAL; + else if (pll_ref_hz < 19200000) + cfg->pll_ipdiv = 1; + else if (pll_ref_hz < 38400000) + cfg->pll_ipdiv = 2; + else if (pll_ref_hz < 76800000) + cfg->pll_ipdiv = 4; + else + cfg->pll_ipdiv = 8; + + dlane_bps = opts->hs_clk_rate; + + if (dlane_bps > 2500000000UL || dlane_bps < 160000000UL) + return -EINVAL; + else if (dlane_bps >= 1250000000) + cfg->pll_opdiv = 1; + else if (dlane_bps >= 630000000) + cfg->pll_opdiv = 2; + else if (dlane_bps >= 320000000) + cfg->pll_opdiv = 4; + else if (dlane_bps >= 160000000) + cfg->pll_opdiv = 8; + + cfg->pll_fbdiv = DIV_ROUND_UP_ULL(dlane_bps * 2 * cfg->pll_opdiv * + cfg->pll_ipdiv, + pll_ref_hz); + + return 0; +} + +static int cdns_dphy_setup_psm(struct cdns_dphy *dphy) +{ + unsigned long psm_clk_hz = clk_get_rate(dphy->psm_clk); + unsigned long psm_div; + + if (!psm_clk_hz || psm_clk_hz > 100000000) + return -EINVAL; + + psm_div = DIV_ROUND_CLOSEST(psm_clk_hz, 1000000); + if (dphy->ops->set_psm_div) + dphy->ops->set_psm_div(dphy, psm_div); + + return 0; +} + +static void cdns_dphy_set_clk_lane_cfg(struct cdns_dphy *dphy, + enum cdns_dphy_clk_lane_cfg cfg) +{ + if (dphy->ops->set_clk_lane_cfg) + dphy->ops->set_clk_lane_cfg(dphy, cfg); +} + +static void cdns_dphy_set_pll_cfg(struct cdns_dphy *dphy, + const struct cdns_dphy_cfg *cfg) +{ + if (dphy->ops->set_pll_cfg) + dphy->ops->set_pll_cfg(dphy, cfg); +} + +static unsigned long cdns_dphy_get_wakeup_time_ns(struct cdns_dphy *dphy) +{ + return dphy->ops->get_wakeup_time_ns(dphy); +} + +static unsigned long cdns_dphy_ref_get_wakeup_time_ns(struct cdns_dphy *dphy) +{ + /* Default wakeup time is 800 ns (in a simulated environment). */ + return 800; +} + +static void cdns_dphy_ref_set_pll_cfg(struct cdns_dphy *dphy, + const struct cdns_dphy_cfg *cfg) +{ + u32 fbdiv_low, fbdiv_high; + + fbdiv_low = (cfg->pll_fbdiv / 4) - 2; + fbdiv_high = cfg->pll_fbdiv - fbdiv_low - 2; + + writel(DPHY_CMN_IPDIV_FROM_REG | DPHY_CMN_OPDIV_FROM_REG | + DPHY_CMN_IPDIV(cfg->pll_ipdiv) | + DPHY_CMN_OPDIV(cfg->pll_opdiv), + dphy->regs + DPHY_CMN_OPIPDIV); + writel(DPHY_CMN_FBDIV_FROM_REG | + DPHY_CMN_FBDIV_VAL(fbdiv_low, fbdiv_high), + dphy->regs + DPHY_CMN_FBDIV); + writel(DPHY_CMN_PWM_HIGH(6) | DPHY_CMN_PWM_LOW(0x101) | + DPHY_CMN_PWM_DIV(0x8), + dphy->regs + DPHY_CMN_PWM); +} + +static void cdns_dphy_ref_set_psm_div(struct cdns_dphy *dphy, u8 div) +{ + writel(DPHY_PSM_CFG_FROM_REG | DPHY_PSM_CLK_DIV(div), + dphy->regs + DPHY_PSM_CFG); +} + +/* + * 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 + * to wire things in the SoC. + */ +static const struct cdns_dphy_ops ref_dphy_ops = { + .get_wakeup_time_ns = cdns_dphy_ref_get_wakeup_time_ns, + .set_pll_cfg = cdns_dphy_ref_set_pll_cfg, + .set_psm_div = cdns_dphy_ref_set_psm_div, +}; + +static int cdns_dphy_config_from_opts(struct phy *phy, + struct phy_configure_opts_mipi_dphy *opts, + struct cdns_dphy_cfg *cfg) +{ + struct cdns_dphy *dphy = phy_get_drvdata(phy); + unsigned int dsi_hfp_ext = 0; + int ret; + + ret = phy_mipi_dphy_config_validate(opts); + if (ret) + return ret; + + ret = cdns_dsi_get_dphy_pll_cfg(dphy, cfg, + opts, &dsi_hfp_ext); + if (ret) + return ret; + + opts->wakeup = cdns_dphy_get_wakeup_time_ns(dphy) / 1000; + + return 0; +} + +static int cdns_dphy_validate(struct phy *phy, enum phy_mode mode, int submode, + union phy_configure_opts *opts) +{ + struct cdns_dphy_cfg cfg = { 0 }; + + if (mode != PHY_MODE_MIPI_DPHY) + return -EINVAL; + + return cdns_dphy_config_from_opts(phy, &opts->mipi_dphy, &cfg); +} + +static int cdns_dphy_configure(struct phy *phy, union phy_configure_opts *opts) +{ + struct cdns_dphy *dphy = phy_get_drvdata(phy); + struct cdns_dphy_cfg cfg = { 0 }; + int ret; + + ret = cdns_dphy_config_from_opts(phy, &opts->mipi_dphy, &cfg); + if (ret) + return ret; + + /* + * Configure the internal PSM clk divider so that the DPHY has a + * 1MHz clk (or something close). + */ + ret = cdns_dphy_setup_psm(dphy); + if (ret) + return ret; + + /* + * Configure attach clk lanes to data lanes: the DPHY has 2 clk lanes + * and 8 data lanes, each clk lane can be attache different set of + * data lanes. The 2 groups are named 'left' and 'right', so here we + * just say that we want the 'left' clk lane to drive the 'left' data + * lanes. + */ + cdns_dphy_set_clk_lane_cfg(dphy, DPHY_CLK_CFG_LEFT_DRIVES_LEFT); + + /* + * Configure the DPHY PLL that will be used to generate the TX byte + * clk. + */ + cdns_dphy_set_pll_cfg(dphy, &cfg); + + return 0; +} + +static int cdns_dphy_power_on(struct phy *phy) +{ + struct cdns_dphy *dphy = phy_get_drvdata(phy); + + clk_prepare_enable(dphy->psm_clk); + clk_prepare_enable(dphy->pll_ref_clk); + + /* Start TX state machine. */ + writel(DPHY_CMN_SSM_EN | DPHY_CMN_TX_MODE_EN, + dphy->regs + DPHY_CMN_SSM); + + return 0; +} + +static int cdns_dphy_power_off(struct phy *phy) +{ + struct cdns_dphy *dphy = phy_get_drvdata(phy); + + clk_disable_unprepare(dphy->pll_ref_clk); + clk_disable_unprepare(dphy->psm_clk); + + 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, +}; + +static int cdns_dphy_probe(struct platform_device *pdev) +{ + struct phy_provider *phy_provider; + struct cdns_dphy *dphy; + struct resource *res; + int ret; + + dphy = devm_kzalloc(&pdev->dev, sizeof(*dphy), GFP_KERNEL); + if (!dphy) + return -ENOMEM; + dev_set_drvdata(&pdev->dev, dphy); + + dphy->ops = of_device_get_match_data(&pdev->dev); + if (!dphy->ops) + return -EINVAL; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + dphy->regs = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(dphy->regs)) + return PTR_ERR(dphy->regs); + + dphy->psm_clk = devm_clk_get(&pdev->dev, "psm"); + if (IS_ERR(dphy->psm_clk)) + return PTR_ERR(dphy->psm_clk); + + dphy->pll_ref_clk = devm_clk_get(&pdev->dev, "pll_ref"); + if (IS_ERR(dphy->pll_ref_clk)) + return PTR_ERR(dphy->pll_ref_clk); + + if (dphy->ops->probe) { + ret = dphy->ops->probe(dphy); + if (ret) + return ret; + } + + dphy->phy = devm_phy_create(&pdev->dev, NULL, &cdns_dphy_ops); + if (IS_ERR(dphy->phy)) { + dev_err(&pdev->dev, "failed to create PHY\n"); + if (dphy->ops->remove) + dphy->ops->remove(dphy); + return PTR_ERR(dphy->phy); + } + + phy_set_drvdata(dphy->phy, dphy); + phy_provider = devm_of_phy_provider_register(&pdev->dev, + of_phy_simple_xlate); + + return PTR_ERR_OR_ZERO(phy_provider); +} + +static int cdns_dphy_remove(struct platform_device *pdev) +{ + struct cdns_dphy *dphy = dev_get_drvdata(&pdev->dev); + + if (dphy->ops->remove) + dphy->ops->remove(dphy); + + return 0; +} + +static const struct of_device_id cdns_dphy_of_match[] = { + { .compatible = "cdns,dphy", .data = &ref_dphy_ops }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, cdns_dphy_of_match); + +static struct platform_driver cdns_dphy_platform_driver = { + .probe = cdns_dphy_probe, + .remove = cdns_dphy_remove, + .driver = { + .name = "cdns-mipi-dphy", + .of_match_table = cdns_dphy_of_match, + }, +}; +module_platform_driver(cdns_dphy_platform_driver); + +MODULE_AUTHOR("Maxime Ripard <maxime.ripard@bootlin.com>"); +MODULE_DESCRIPTION("Cadence MIPI D-PHY Driver"); +MODULE_LICENSE("GPL"); |