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Subject[PATCH v3 06/10] video: add support of STM32 MIPI DSI controller driver
Date
Add the STM32 DSI controller driver that uses the Synopsys DesignWare
MIPI DSI host controller bridge.

Signed-off-by: yannick fertre <yannick.fertre@st.com>
---
drivers/video/stm32/Kconfig | 10 +
drivers/video/stm32/Makefile | 1 +
drivers/video/stm32/stm32_dsi.c | 426 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 437 insertions(+)
create mode 100644 drivers/video/stm32/stm32_dsi.c

diff --git a/drivers/video/stm32/Kconfig b/drivers/video/stm32/Kconfig
index 113a2bb..2ea6f18 100644
--- a/drivers/video/stm32/Kconfig
+++ b/drivers/video/stm32/Kconfig
@@ -15,6 +15,16 @@ menuconfig VIDEO_STM32
DSI. This option enables these supports which can be used on
devices which have RGB TFT or DSI display connected.

+config VIDEO_STM32_DSI
+ bool "Enable STM32 DSI video support"
+ depends on VIDEO_STM32
+ select VIDEO_MIPI_DSI
+ select VIDEO_BRIDGE
+ select VIDEO_DW_MIPI_DSI
+ help
+ This option enables support DSI internal bridge which can be used on
+ devices which have DSI display connected.
+
config VIDEO_STM32_MAX_XRES
int "Maximum horizontal resolution (for memory allocation purposes)"
depends on VIDEO_STM32
diff --git a/drivers/video/stm32/Makefile b/drivers/video/stm32/Makefile
index 372a2e1..f8c3ff7 100644
--- a/drivers/video/stm32/Makefile
+++ b/drivers/video/stm32/Makefile
@@ -8,3 +8,4 @@
#

obj-${CONFIG_VIDEO_STM32} = stm32_ltdc.o
+obj-${CONFIG_VIDEO_STM32_DSI} += stm32_dsi.o
diff --git a/drivers/video/stm32/stm32_dsi.c b/drivers/video/stm32/stm32_dsi.c
new file mode 100644
index 0000000..949db4f
--- /dev/null
+++ b/drivers/video/stm32/stm32_dsi.c
@@ -0,0 +1,426 @@
+/*
+ * Copyright (C) 2018 STMicroelectronics - All Rights Reserved
+ * Author(s): Philippe Cornu <philippe.cornu@st.com> for STMicroelectronics.
+ * Yannick Fertre <yannick.fertre@st.com> for STMicroelectronics.
+ *
+ * This driver is based on the mipi dsi driver from
+ * drivers/gpu/drm/stm/dw_mipi_dsi-stm.c (kernel linux).
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <dw_mipi_dsi.h>
+#include <mipi_display.h>
+#include <panel.h>
+#include <reset.h>
+#include <video.h>
+#include <video_bridge.h>
+#include <asm/io.h>
+#include <asm/arch/gpio.h>
+#include <dm/device-internal.h>
+#include <linux/iopoll.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
+
+/* Timeout for regulator on/off, pll lock/unlock & fifo empty */
+#define TIMEOUT_US 200000
+
+struct stm32_dsi_priv {
+ struct mipi_dsi_device device;
+ void __iomem *base;
+ struct udevice *panel;
+ u32 pllref_clk;
+ u32 hw_version;
+ int lane_min_kbps;
+ int lane_max_kbps;
+};
+
+static inline void dsi_write(struct stm32_dsi_priv *dsi, u32 reg, u32 val)
+{
+ writel(val, dsi->base + reg);
+}
+
+static inline u32 dsi_read(struct stm32_dsi_priv *dsi, u32 reg)
+{
+ return readl(dsi->base + reg);
+}
+
+static inline void dsi_set(struct stm32_dsi_priv *dsi, u32 reg, u32 mask)
+{
+ dsi_write(dsi, reg, dsi_read(dsi, reg) | mask);
+}
+
+static inline void dsi_clear(struct stm32_dsi_priv *dsi, u32 reg, u32 mask)
+{
+ dsi_write(dsi, reg, dsi_read(dsi, reg) & ~mask);
+}
+
+static inline void dsi_update_bits(struct stm32_dsi_priv *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(u32 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:
+ pr_err("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 stm32_dsi_priv *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 dsi_phy_init(void *priv_data)
+{
+ struct mipi_dsi_device *device = priv_data;
+ struct udevice *dev = device->dev;
+ struct stm32_dsi_priv *dsi = dev_get_priv(dev);
+ 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,
+ TIMEOUT_US);
+ if (ret) {
+ dev_err(dev, "!TIMEOUT! waiting REGU\n");
+ return ret;
+ }
+
+ /* 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,
+ TIMEOUT_US);
+ if (ret) {
+ dev_err(dev, "!TIMEOUT! waiting PLL\n");
+ return ret;
+ }
+
+ /* Enable the DSI wrapper */
+ dsi_set(dsi, DSI_WCR, WCR_DSIEN);
+
+ return 0;
+}
+
+static int dsi_get_lane_mbps(void *priv_data, struct display_timing *timings,
+ u32 lanes, u32 format, unsigned int *lane_mbps)
+{
+ struct mipi_dsi_device *device = priv_data;
+ struct udevice *dev = device->dev;
+ struct stm32_dsi_priv *dsi = dev_get_priv(dev);
+ 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 = dsi->pllref_clk / 1000;
+
+ /* Compute requested pll out */
+ bpp = mipi_dsi_pixel_format_to_bpp(format);
+ pll_out_khz = (timings->pixelclock.typ / 1000) * 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;
+ dev_warn(dev, "Warning max phy mbps is used\n");
+ }
+ if (pll_out_khz < dsi->lane_min_kbps) {
+ pll_out_khz = dsi->lane_min_kbps;
+ dev_warn(dev, "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) {
+ dev_err(dev, "Warning dsi_pll_get_params(): bad params\n");
+ return ret;
+ }
+
+ /* 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;
+
+ dev_info(dev, "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 = dsi_phy_init,
+ .get_lane_mbps = dsi_get_lane_mbps,
+};
+
+static int stm32_dsi_attach(struct udevice *dev)
+{
+ struct stm32_dsi_priv *priv = dev_get_priv(dev);
+ struct dw_mipi_dsi_plat_data *platdata = dev_get_platdata(dev);
+ struct mipi_dsi_device *device = &priv->device;
+ int ret;
+
+ platdata->max_data_lanes = 2;
+ platdata->phy_ops = &dw_mipi_dsi_stm_phy_ops;
+
+ ret = uclass_first_device(UCLASS_PANEL, &platdata->panel);
+ if (ret) {
+ dev_err(dev, "panel device error %d\n", ret);
+ return ret;
+ }
+
+ ret = dw_mipi_dsi_init_bridge(device);
+ if (ret) {
+ dev_err(dev, "failed to initialize mipi dsi host\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int stm32_dsi_set_backlight(struct udevice *dev, int percent)
+{
+ struct dw_mipi_dsi_plat_data *dplat = dev_get_platdata(dev);
+ struct stm32_dsi_priv *priv = dev_get_priv(dev);
+ struct mipi_dsi_device *device = &priv->device;
+ struct udevice *panel = dplat->panel;
+ struct mipi_dsi_panel_plat *mplat;
+ int ret;
+
+ mplat = dev_get_platdata(panel);
+ mplat->device = device;
+
+ ret = panel_enable_backlight(panel);
+ if (ret) {
+ dev_err(dev, "panel %s enable backlight error %d\n",
+ panel->name, ret);
+ return ret;
+ }
+
+ dw_mipi_dsi_bridge_enable(device);
+
+ return 0;
+}
+
+static int stm32_dsi_probe(struct udevice *dev)
+{
+ struct stm32_dsi_priv *priv = dev_get_priv(dev);
+ struct mipi_dsi_device *device = &priv->device;
+ struct reset_ctl rst;
+ struct clk clk;
+ int ret;
+
+ device->dev = dev;
+
+ priv->base = (void *)dev_read_addr(dev);
+ if ((fdt_addr_t)priv->base == FDT_ADDR_T_NONE) {
+ dev_err(dev, "dsi dt register address error\n");
+ return -EINVAL;
+ }
+
+ ret = clk_get_by_name(device->dev, "pclk", &clk);
+ if (ret) {
+ dev_err(dev, "peripheral clock get error %d\n", ret);
+ return -ENODEV;
+ }
+
+ ret = clk_enable(&clk);
+ if (ret) {
+ dev_err(dev, "peripheral clock enable error %d\n", ret);
+ return -ENODEV;
+ }
+
+ ret = clk_get_by_name(dev, "ref", &clk);
+ if (ret) {
+ dev_err(dev, "pll reference clock get error %d\n", ret);
+ return ret;
+ }
+
+ priv->pllref_clk = (unsigned int)clk_get_rate(&clk);
+
+ ret = reset_get_by_index(device->dev, 0, &rst);
+ if (ret) {
+ dev_err(dev, "missing dsi hardware reset\n");
+ return -ENODEV;
+ }
+
+ /* Reset */
+ reset_deassert(&rst);
+
+ return 0;
+}
+
+struct video_bridge_ops stm32_dsi_ops = {
+ .attach = stm32_dsi_attach,
+ .set_backlight = stm32_dsi_set_backlight,
+};
+
+static const struct udevice_id stm32_dsi_ids[] = {
+ { .compatible = "st,stm32-dsi"},
+ { }
+};
+
+U_BOOT_DRIVER(stm32_dsi) = {
+ .name = "stm32-display-dsi",
+ .id = UCLASS_VIDEO_BRIDGE,
+ .of_match = stm32_dsi_ids,
+ .bind = dm_scan_fdt_dev,
+ .probe = stm32_dsi_probe,
+ .ops = &stm32_dsi_ops,
+ .priv_auto_alloc_size = sizeof(struct stm32_dsi_priv),
+ .platdata_auto_alloc_size = sizeof(struct dw_mipi_dsi_plat_data),
+};
--
1.9.1
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