| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (C) STMicroelectronics SA 2017 |
| * |
| * Authors: Philippe Cornu <philippe.cornu@st.com> |
| * Yannick Fertre <yannick.fertre@st.com> |
| */ |
| |
| #include <linux/clk.h> |
| #include <linux/iopoll.h> |
| #include <linux/module.h> |
| #include <drm/drmP.h> |
| #include <drm/drm_mipi_dsi.h> |
| #include <drm/bridge/dw_mipi_dsi.h> |
| #include <video/mipi_display.h> |
| |
| #define HWVER_130 0x31333000 /* IP version 1.30 */ |
| #define HWVER_131 0x31333100 /* IP version 1.31 */ |
| |
| /* DSI digital registers & bit definitions */ |
| #define DSI_VERSION 0x00 |
| #define VERSION GENMASK(31, 8) |
| |
| /* DSI wrapper registers & bit definitions */ |
| /* Note: registers are named as in the Reference Manual */ |
| #define DSI_WCFGR 0x0400 /* Wrapper ConFiGuration Reg */ |
| #define WCFGR_DSIM BIT(0) /* DSI Mode */ |
| #define WCFGR_COLMUX GENMASK(3, 1) /* COLor MUltipleXing */ |
| |
| #define DSI_WCR 0x0404 /* Wrapper Control Reg */ |
| #define WCR_DSIEN BIT(3) /* DSI ENable */ |
| |
| #define DSI_WISR 0x040C /* Wrapper Interrupt and Status Reg */ |
| #define WISR_PLLLS BIT(8) /* PLL Lock Status */ |
| #define WISR_RRS BIT(12) /* Regulator Ready Status */ |
| |
| #define DSI_WPCR0 0x0418 /* Wrapper Phy Conf Reg 0 */ |
| #define WPCR0_UIX4 GENMASK(5, 0) /* Unit Interval X 4 */ |
| #define WPCR0_TDDL BIT(16) /* Turn Disable Data Lanes */ |
| |
| #define DSI_WRPCR 0x0430 /* Wrapper Regulator & Pll Ctrl Reg */ |
| #define WRPCR_PLLEN BIT(0) /* PLL ENable */ |
| #define WRPCR_NDIV GENMASK(8, 2) /* pll loop DIVision Factor */ |
| #define WRPCR_IDF GENMASK(14, 11) /* pll Input Division Factor */ |
| #define WRPCR_ODF GENMASK(17, 16) /* pll Output Division Factor */ |
| #define WRPCR_REGEN BIT(24) /* REGulator ENable */ |
| #define WRPCR_BGREN BIT(28) /* BandGap Reference ENable */ |
| #define IDF_MIN 1 |
| #define IDF_MAX 7 |
| #define NDIV_MIN 10 |
| #define NDIV_MAX 125 |
| #define ODF_MIN 1 |
| #define ODF_MAX 8 |
| |
| /* dsi color format coding according to the datasheet */ |
| enum dsi_color { |
| DSI_RGB565_CONF1, |
| DSI_RGB565_CONF2, |
| DSI_RGB565_CONF3, |
| DSI_RGB666_CONF1, |
| DSI_RGB666_CONF2, |
| DSI_RGB888, |
| }; |
| |
| #define LANE_MIN_KBPS 31250 |
| #define LANE_MAX_KBPS 500000 |
| |
| /* Sleep & timeout for regulator on/off, pll lock/unlock & fifo empty */ |
| #define SLEEP_US 1000 |
| #define TIMEOUT_US 200000 |
| |
| struct dw_mipi_dsi_stm { |
| void __iomem *base; |
| struct clk *pllref_clk; |
| struct dw_mipi_dsi *dsi; |
| u32 hw_version; |
| int lane_min_kbps; |
| int lane_max_kbps; |
| }; |
| |
| static inline void dsi_write(struct dw_mipi_dsi_stm *dsi, u32 reg, u32 val) |
| { |
| writel(val, dsi->base + reg); |
| } |
| |
| static inline u32 dsi_read(struct dw_mipi_dsi_stm *dsi, u32 reg) |
| { |
| return readl(dsi->base + reg); |
| } |
| |
| static inline void dsi_set(struct dw_mipi_dsi_stm *dsi, u32 reg, u32 mask) |
| { |
| dsi_write(dsi, reg, dsi_read(dsi, reg) | mask); |
| } |
| |
| static inline void dsi_clear(struct dw_mipi_dsi_stm *dsi, u32 reg, u32 mask) |
| { |
| dsi_write(dsi, reg, dsi_read(dsi, reg) & ~mask); |
| } |
| |
| static inline void dsi_update_bits(struct dw_mipi_dsi_stm *dsi, u32 reg, |
| u32 mask, u32 val) |
| { |
| dsi_write(dsi, reg, (dsi_read(dsi, reg) & ~mask) | val); |
| } |
| |
| static enum dsi_color dsi_color_from_mipi(enum mipi_dsi_pixel_format fmt) |
| { |
| switch (fmt) { |
| case MIPI_DSI_FMT_RGB888: |
| return DSI_RGB888; |
| case MIPI_DSI_FMT_RGB666: |
| return DSI_RGB666_CONF2; |
| case MIPI_DSI_FMT_RGB666_PACKED: |
| return DSI_RGB666_CONF1; |
| case MIPI_DSI_FMT_RGB565: |
| return DSI_RGB565_CONF1; |
| default: |
| DRM_DEBUG_DRIVER("MIPI color invalid, so we use rgb888\n"); |
| } |
| return DSI_RGB888; |
| } |
| |
| static int dsi_pll_get_clkout_khz(int clkin_khz, int idf, int ndiv, int odf) |
| { |
| int divisor = idf * odf; |
| |
| /* prevent from division by 0 */ |
| if (!divisor) |
| return 0; |
| |
| return DIV_ROUND_CLOSEST(clkin_khz * ndiv, divisor); |
| } |
| |
| static int dsi_pll_get_params(struct dw_mipi_dsi_stm *dsi, |
| int clkin_khz, int clkout_khz, |
| int *idf, int *ndiv, int *odf) |
| { |
| int i, o, n, n_min, n_max; |
| int fvco_min, fvco_max, delta, best_delta; /* all in khz */ |
| |
| /* Early checks preventing division by 0 & odd results */ |
| if (clkin_khz <= 0 || clkout_khz <= 0) |
| return -EINVAL; |
| |
| fvco_min = dsi->lane_min_kbps * 2 * ODF_MAX; |
| fvco_max = dsi->lane_max_kbps * 2 * ODF_MIN; |
| |
| best_delta = 1000000; /* big started value (1000000khz) */ |
| |
| for (i = IDF_MIN; i <= IDF_MAX; i++) { |
| /* Compute ndiv range according to Fvco */ |
| n_min = ((fvco_min * i) / (2 * clkin_khz)) + 1; |
| n_max = (fvco_max * i) / (2 * clkin_khz); |
| |
| /* No need to continue idf loop if we reach ndiv max */ |
| if (n_min >= NDIV_MAX) |
| break; |
| |
| /* Clamp ndiv to valid values */ |
| if (n_min < NDIV_MIN) |
| n_min = NDIV_MIN; |
| if (n_max > NDIV_MAX) |
| n_max = NDIV_MAX; |
| |
| for (o = ODF_MIN; o <= ODF_MAX; o *= 2) { |
| n = DIV_ROUND_CLOSEST(i * o * clkout_khz, clkin_khz); |
| /* Check ndiv according to vco range */ |
| if (n < n_min || n > n_max) |
| continue; |
| /* Check if new delta is better & saves parameters */ |
| delta = dsi_pll_get_clkout_khz(clkin_khz, i, n, o) - |
| clkout_khz; |
| if (delta < 0) |
| delta = -delta; |
| if (delta < best_delta) { |
| *idf = i; |
| *ndiv = n; |
| *odf = o; |
| best_delta = delta; |
| } |
| /* fast return in case of "perfect result" */ |
| if (!delta) |
| return 0; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int dw_mipi_dsi_phy_init(void *priv_data) |
| { |
| struct dw_mipi_dsi_stm *dsi = priv_data; |
| u32 val; |
| int ret; |
| |
| /* Enable the regulator */ |
| dsi_set(dsi, DSI_WRPCR, WRPCR_REGEN | WRPCR_BGREN); |
| ret = readl_poll_timeout(dsi->base + DSI_WISR, val, val & WISR_RRS, |
| SLEEP_US, TIMEOUT_US); |
| if (ret) |
| DRM_DEBUG_DRIVER("!TIMEOUT! waiting REGU, let's continue\n"); |
| |
| /* Enable the DSI PLL & wait for its lock */ |
| dsi_set(dsi, DSI_WRPCR, WRPCR_PLLEN); |
| ret = readl_poll_timeout(dsi->base + DSI_WISR, val, val & WISR_PLLLS, |
| SLEEP_US, TIMEOUT_US); |
| if (ret) |
| DRM_DEBUG_DRIVER("!TIMEOUT! waiting PLL, let's continue\n"); |
| |
| /* Enable the DSI wrapper */ |
| dsi_set(dsi, DSI_WCR, WCR_DSIEN); |
| |
| return 0; |
| } |
| |
| static int |
| dw_mipi_dsi_get_lane_mbps(void *priv_data, struct drm_display_mode *mode, |
| unsigned long mode_flags, u32 lanes, u32 format, |
| unsigned int *lane_mbps) |
| { |
| struct dw_mipi_dsi_stm *dsi = priv_data; |
| unsigned int idf, ndiv, odf, pll_in_khz, pll_out_khz; |
| int ret, bpp; |
| u32 val; |
| |
| /* Update lane capabilities according to hw version */ |
| dsi->hw_version = dsi_read(dsi, DSI_VERSION) & VERSION; |
| dsi->lane_min_kbps = LANE_MIN_KBPS; |
| dsi->lane_max_kbps = LANE_MAX_KBPS; |
| if (dsi->hw_version == HWVER_131) { |
| dsi->lane_min_kbps *= 2; |
| dsi->lane_max_kbps *= 2; |
| } |
| |
| pll_in_khz = (unsigned int)(clk_get_rate(dsi->pllref_clk) / 1000); |
| |
| /* Compute requested pll out */ |
| bpp = mipi_dsi_pixel_format_to_bpp(format); |
| pll_out_khz = mode->clock * bpp / lanes; |
| /* Add 20% to pll out to be higher than pixel bw (burst mode only) */ |
| pll_out_khz = (pll_out_khz * 12) / 10; |
| if (pll_out_khz > dsi->lane_max_kbps) { |
| pll_out_khz = dsi->lane_max_kbps; |
| DRM_WARN("Warning max phy mbps is used\n"); |
| } |
| if (pll_out_khz < dsi->lane_min_kbps) { |
| pll_out_khz = dsi->lane_min_kbps; |
| DRM_WARN("Warning min phy mbps is used\n"); |
| } |
| |
| /* Compute best pll parameters */ |
| idf = 0; |
| ndiv = 0; |
| odf = 0; |
| ret = dsi_pll_get_params(dsi, pll_in_khz, pll_out_khz, |
| &idf, &ndiv, &odf); |
| if (ret) |
| DRM_WARN("Warning dsi_pll_get_params(): bad params\n"); |
| |
| /* Get the adjusted pll out value */ |
| pll_out_khz = dsi_pll_get_clkout_khz(pll_in_khz, idf, ndiv, odf); |
| |
| /* Set the PLL division factors */ |
| dsi_update_bits(dsi, DSI_WRPCR, WRPCR_NDIV | WRPCR_IDF | WRPCR_ODF, |
| (ndiv << 2) | (idf << 11) | ((ffs(odf) - 1) << 16)); |
| |
| /* Compute uix4 & set the bit period in high-speed mode */ |
| val = 4000000 / pll_out_khz; |
| dsi_update_bits(dsi, DSI_WPCR0, WPCR0_UIX4, val); |
| |
| /* Select video mode by resetting DSIM bit */ |
| dsi_clear(dsi, DSI_WCFGR, WCFGR_DSIM); |
| |
| /* Select the color coding */ |
| dsi_update_bits(dsi, DSI_WCFGR, WCFGR_COLMUX, |
| dsi_color_from_mipi(format) << 1); |
| |
| *lane_mbps = pll_out_khz / 1000; |
| |
| DRM_DEBUG_DRIVER("pll_in %ukHz pll_out %ukHz lane_mbps %uMHz\n", |
| pll_in_khz, pll_out_khz, *lane_mbps); |
| |
| return 0; |
| } |
| |
| static const struct dw_mipi_dsi_phy_ops dw_mipi_dsi_stm_phy_ops = { |
| .init = dw_mipi_dsi_phy_init, |
| .get_lane_mbps = dw_mipi_dsi_get_lane_mbps, |
| }; |
| |
| static struct dw_mipi_dsi_plat_data dw_mipi_dsi_stm_plat_data = { |
| .max_data_lanes = 2, |
| .phy_ops = &dw_mipi_dsi_stm_phy_ops, |
| }; |
| |
| static const struct of_device_id dw_mipi_dsi_stm_dt_ids[] = { |
| { .compatible = "st,stm32-dsi", .data = &dw_mipi_dsi_stm_plat_data, }, |
| { }, |
| }; |
| MODULE_DEVICE_TABLE(of, dw_mipi_dsi_stm_dt_ids); |
| |
| static int dw_mipi_dsi_stm_probe(struct platform_device *pdev) |
| { |
| struct device *dev = &pdev->dev; |
| struct dw_mipi_dsi_stm *dsi; |
| struct resource *res; |
| int ret; |
| |
| dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL); |
| if (!dsi) |
| return -ENOMEM; |
| |
| res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| dsi->base = devm_ioremap_resource(dev, res); |
| if (IS_ERR(dsi->base)) { |
| DRM_ERROR("Unable to get dsi registers\n"); |
| return PTR_ERR(dsi->base); |
| } |
| |
| dsi->pllref_clk = devm_clk_get(dev, "ref"); |
| if (IS_ERR(dsi->pllref_clk)) { |
| ret = PTR_ERR(dsi->pllref_clk); |
| dev_err(dev, "Unable to get pll reference clock: %d\n", ret); |
| return ret; |
| } |
| |
| ret = clk_prepare_enable(dsi->pllref_clk); |
| if (ret) { |
| dev_err(dev, "%s: Failed to enable pllref_clk\n", __func__); |
| return ret; |
| } |
| |
| dw_mipi_dsi_stm_plat_data.base = dsi->base; |
| dw_mipi_dsi_stm_plat_data.priv_data = dsi; |
| |
| platform_set_drvdata(pdev, dsi); |
| |
| dsi->dsi = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data); |
| if (IS_ERR(dsi->dsi)) { |
| DRM_ERROR("Failed to initialize mipi dsi host\n"); |
| clk_disable_unprepare(dsi->pllref_clk); |
| return PTR_ERR(dsi->dsi); |
| } |
| |
| return 0; |
| } |
| |
| static int dw_mipi_dsi_stm_remove(struct platform_device *pdev) |
| { |
| struct dw_mipi_dsi_stm *dsi = platform_get_drvdata(pdev); |
| |
| clk_disable_unprepare(dsi->pllref_clk); |
| dw_mipi_dsi_remove(dsi->dsi); |
| |
| return 0; |
| } |
| |
| static struct platform_driver dw_mipi_dsi_stm_driver = { |
| .probe = dw_mipi_dsi_stm_probe, |
| .remove = dw_mipi_dsi_stm_remove, |
| .driver = { |
| .of_match_table = dw_mipi_dsi_stm_dt_ids, |
| .name = "stm32-display-dsi", |
| }, |
| }; |
| |
| module_platform_driver(dw_mipi_dsi_stm_driver); |
| |
| MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>"); |
| MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>"); |
| MODULE_DESCRIPTION("STMicroelectronics DW MIPI DSI host controller driver"); |
| MODULE_LICENSE("GPL v2"); |