Add the STM32 DSI host driver that uses the Synopsys DesignWare MIPI DSI DRM bridge.
Signed-off-by: Philippe CORNU philippe.cornu@st.com Reviewed-by: Neil Armstrong narmstrong@baylibre.com --- drivers/gpu/drm/stm/Kconfig | 7 + drivers/gpu/drm/stm/Makefile | 2 + drivers/gpu/drm/stm/dw_mipi_dsi-stm.c | 352 ++++++++++++++++++++++++++++++++++ 3 files changed, 361 insertions(+) create mode 100644 drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
diff --git a/drivers/gpu/drm/stm/Kconfig b/drivers/gpu/drm/stm/Kconfig index 4b88223..f9462bc 100644 --- a/drivers/gpu/drm/stm/Kconfig +++ b/drivers/gpu/drm/stm/Kconfig @@ -14,3 +14,10 @@ config DRM_STM STMicroelectronics STM32 MCUs. To compile this driver as a module, choose M here: the module will be called stm-drm. + +config DRM_STM_DSI + tristate "STMicroelectronics specific extensions for Synopsys MIPI DSI" + depends on DRM_STM + select DRM_DW_MIPI_DSI + help + Choose this option for MIPI DSI support on STMicroelectronics SoC. diff --git a/drivers/gpu/drm/stm/Makefile b/drivers/gpu/drm/stm/Makefile index a09ecf4..d883adc 100644 --- a/drivers/gpu/drm/stm/Makefile +++ b/drivers/gpu/drm/stm/Makefile @@ -2,4 +2,6 @@ stm-drm-y := \ drv.o \ ltdc.o
+obj-$(CONFIG_DRM_STM_DSI) += dw_mipi_dsi-stm.o + obj-$(CONFIG_DRM_STM) += stm-drm.o diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c new file mode 100644 index 0000000..16ae00e --- /dev/null +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c @@ -0,0 +1,352 @@ +/* + * Copyright (C) STMicroelectronics SA 2017 + * + * Authors: Philippe Cornu philippe.cornu@st.com + * Yannick Fertre yannick.fertre@st.com + * + * License terms: GNU General Public License (GPL), version 2 + */ + +#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> + +/* DSI wrapper register & 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; +}; + +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) +{ + /* prevent from division by 0 */ + if (idf * odf) + return DIV_ROUND_CLOSEST(clkin_khz * ndiv, idf * odf); + + return 0; +} + +static int dsi_pll_get_params(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 = LANE_MIN_KBPS * 2 * ODF_MAX; + fvco_max = 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; + + 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 > LANE_MAX_KBPS) { + pll_out_khz = LANE_MAX_KBPS; + DRM_WARN("Warning max phy mbps is used\n"); + } + if (pll_out_khz < LANE_MIN_KBPS) { + pll_out_khz = 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(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 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); + if (!res) { + DRM_ERROR("Unable to get resource\n"); + return -ENODEV; + } + + 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; + + ret = dw_mipi_dsi_probe(pdev, &dw_mipi_dsi_stm_plat_data); + if (ret) { + DRM_ERROR("Failed to initialize mipi dsi host\n"); + clk_disable_unprepare(dsi->pllref_clk); + } + + return ret; +} + +static int dw_mipi_dsi_stm_remove(struct platform_device *pdev) +{ + struct dw_mipi_dsi_stm *dsi = dw_mipi_dsi_stm_plat_data.priv_data; + + clk_disable_unprepare(dsi->pllref_clk); + dw_mipi_dsi_remove(pdev); + + 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 = "dw_mipi_dsi-stm", + }, +}; + +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");