lkml.org 
[lkml]   [2018]   [Mar]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH v2 06/10] video: add support of STM32 MIPI DSI controller driver
Date
Hi yannick

On 03/02/2018 04:44 PM, yannick fertre wrote:
> 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 | 427 ++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 438 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..3e26433
> --- /dev/null
> +++ b/drivers/video/stm32/stm32_dsi.c
> @@ -0,0 +1,427 @@
> +/*
> + * 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 <asm/io.h>
> +#include <asm/arch/gpio.h>
> +#include <common.h>
> +#include <clk.h>
> +#include <dm.h>
> +#include <dm/device-internal.h>
> +#include <mipi_display.h>
> +#include <dw_mipi_dsi.h>
> +#include <linux/iopoll.h>
> +#include <panel.h>
> +#include <reset.h>
> +#include <video.h>
> +#include <video_bridge.h>
> +
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +#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 stm32_dsi_priv *dsi = dev_get_priv(device->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) {
> + pr_err("!TIMEOUT! waiting REGU\n");

dev_err()

> + 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) {
> + pr_err("!TIMEOUT! waiting PLL\n");

dev_err()

> + 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 stm32_dsi_priv *dsi = dev_get_priv(device->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;
> + pr_warn("Warning max phy mbps is used\n");
> + }
> + if (pll_out_khz < dsi->lane_min_kbps) {
> + pll_out_khz = dsi->lane_min_kbps;
> + pr_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) {
> + pr_warn("Warning dsi_pll_get_params(): bad params\n");

dev_warn() or dev_err() ?

> + 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;
> +
> + pr_info("pll_in %ukHz pll_out %ukHz lane_mbps %uMHz\n",
> + pll_in_khz, pll_out_khz, *lane_mbps);

is it useful to print this each time ? or is it for debug purpose ? in
this case use debug()

> +
> + 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) {
> + pr_err("%s: panel device error %d\n", __func__, ret);

dev_err()

> + return ret;
> + }
> +
> + ret = dw_mipi_dsi_init_bridge(device);
> + if (ret) {
> + pr_err("Failed to initialize mipi dsi host\n");

ditto

> + 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) {
> + pr_err("%s: panel %s enable backlight error %d\n",
> + __func__, panel->name, ret);

ditto

> + 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) {
> + pr_err("%s: dsi dt register address error\n", __func__);

ditto

> + return -EINVAL;
> + }
> +
> + ret = clk_get_by_name(device->dev, "pclk", &clk);
> + if (ret) {
> + pr_err("%s: peripheral clock get error %d\n", __func__, ret);

ditto

> + return -ENODEV;
> + }
> +
> + ret = clk_enable(&clk);
> + if (ret) {
> + pr_err("%s: peripheral clock enable error %d\n", __func__, ret);

ditto

> + return -ENODEV;
> + }
> +
> + ret = clk_get_by_name(dev, "ref", &clk);
> + if (ret) {
> + pr_err("%s: pll reference clock get error %d\n", __func__, ret);

ditto

> + return ret;
> + }
> +
> + priv->pllref_clk = (unsigned int)clk_get_rate(&clk);
> +
> + ret = reset_get_by_index(device->dev, 0, &rst);
> + if (ret) {
> + pr_err("%s: missing dsi hardware reset\n", __func__);

ditto

> + 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),
> +};
>
\
 
 \ /
  Last update: 2018-03-13 09:58    [W:0.157 / U:2.336 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site