From: Marian Cichy <[email protected]>

Add support for the LCD Controller found on i.MX21, i.MX25 and i.MX27

Note there is already a fb driver for this hardware in the tree that is
supposed to be superseded by this one.

Signed-off-by: Uwe Kleine-König <[email protected]>
---
 drivers/gpu/drm/imx/Kconfig                 |   9 +
 drivers/gpu/drm/imx/Makefile                |   2 +
 drivers/gpu/drm/imx/imx21-lcdc/imx21-lcdc.c | 631 ++++++++++++++++++++
 3 files changed, 642 insertions(+)
 create mode 100644 drivers/gpu/drm/imx/imx21-lcdc/imx21-lcdc.c

diff --git a/drivers/gpu/drm/imx/Kconfig b/drivers/gpu/drm/imx/Kconfig
index bb9738c7c825..62b24ea1bbe0 100644
--- a/drivers/gpu/drm/imx/Kconfig
+++ b/drivers/gpu/drm/imx/Kconfig
@@ -42,3 +42,12 @@ config DRM_IMX_HDMI
          Choose this if you want to use HDMI on i.MX6.
 
 source "drivers/gpu/drm/imx/dcss/Kconfig"
+
+config DRM_IMX21_LCDC
+       tristate "Freescale i.MX LCDC displays"
+       depends on DRM && (ARCH_MXC || ARCH_MULTIPLATFORM || COMPILE_TEST)
+       select DRM_GEM_CMA_HELPER
+       select DRM_KMS_HELPER
+       help
+         This driver is for the Liquid Crystal Display Controller (LCDC) found
+         on Freescale i.MX21, i.MX25 and i.MX27.
diff --git a/drivers/gpu/drm/imx/Makefile b/drivers/gpu/drm/imx/Makefile
index b644deffe948..25685230f4f7 100644
--- a/drivers/gpu/drm/imx/Makefile
+++ b/drivers/gpu/drm/imx/Makefile
@@ -10,3 +10,5 @@ obj-$(CONFIG_DRM_IMX_LDB) += imx-ldb.o
 
 obj-$(CONFIG_DRM_IMX_HDMI) += dw_hdmi-imx.o
 obj-$(CONFIG_DRM_IMX_DCSS) += dcss/
+
+obj-$(CONFIG_DRM_IMX21_LCDC) += imx21-lcdc/
diff --git a/drivers/gpu/drm/imx/imx21-lcdc/imx21-lcdc.c 
b/drivers/gpu/drm/imx/imx21-lcdc/imx21-lcdc.c
new file mode 100644
index 000000000000..37e75f728293
--- /dev/null
+++ b/drivers/gpu/drm/imx/imx21-lcdc/imx21-lcdc.c
@@ -0,0 +1,631 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// SPDX-FileCopyrightText: 2020 Marian Cichy <[email protected]>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_gem_atomic_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_of.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_probe_helper.h>
+#include <drm/drm_simple_kms_helper.h>
+#include <drm/drm_vblank.h>
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+
+/* LCDC Screen Start Address Register */
+#define IMX21LCDC_LSSAR                0x0000
+
+/* LCDC Size Register */
+#define IMX21LCDC_LSR          0x0004
+#define   IMX21LCDC_LSR_XMAX           GENMASK(25, 20) /* Screen width (in 
pixels) divided by 16. */
+#define   IMX21LCDC_LSR_YMAX           GENMASK(9, 0)
+
+/* LCDC Virtual Page Width Register */
+#define IMX21LCDC_LVPWR                0x0008
+
+/* LCDC Cursor Position Register */
+#define IMX21LCDC_LCPR         0x000c
+#define   IMX21LCDC_LCPR_CC            GENMASK(31, 30) /* Cursor Control */
+
+/* LCDC Cursor Width Height and Blink Register*/
+#define IMX21LCDC_LCWHB                0x0010
+
+/* LCDC Color Cursor Mapping Register */
+#define IMX21LCDC_LCCMR                0x0014
+
+/* LCDC Panel Configuration Register */
+#define IMX21LCDC_LPCR         0x0018
+#define   IMX21LCDC_LPCR_PCD           GENMASK(5, 0)
+#define   IMX21LCDC_LPCR_SHARP         BIT(6)
+#define   IMX21LCDC_LPCR_SCLKSEL       BIT(7)
+#define   IMX21LCDC_LPCR_ACD           GENMASK(14, 8)
+#define   IMX21LCDC_LPCR_ACDSEL                BIT(15)
+#define   IMX21LCDC_LPCR_REV_VS                BIT(16)
+#define   IMX21LCDC_LPCR_SWAP_SEL      BIT(17)
+#define   IMX21LCDC_LPCR_END_SEL       BIT(18)
+#define   IMX21LCDC_LPCR_SCLKIDLE      BIT(19)
+#define   IMX21LCDC_LPCR_OEPOL         BIT(20)
+#define   IMX21LCDC_LPCR_CLKPOL                BIT(21)
+#define   IMX21LCDC_LPCR_LPPOL         BIT(22)
+#define   IMX21LCDC_LPCR_FLMPOL                BIT(23)
+#define   IMX21LCDC_LPCR_PIXPOL                BIT(24)
+#define   IMX21LCDC_LPCR_BPIX          GENMASK(27, 25)
+#define   IMX21LCDC_LPCR_PBSIZ         GENMASK(29, 28)
+#define   IMX21LCDC_LPCR_COLOR         BIT(30)
+#define   IMX21LCDC_LPCR_TFT           BIT(31)
+
+/* LCDC Horizontal Configuration Register */
+#define IMX21LCDC_LHCR         0x001c
+#define   IMX21LCDC_LHCR_H_WIDTH       GENMASK(31, 26)
+#define   IMX21LCDC_LHCR_H_BPORCH      GENMASK(7, 0)
+#define   IMX21LCDC_LHCR_H_FPORCH      GENMASK(15, 8)
+
+/* LCDC Vertical Configuration Register */
+#define IMX21LCDC_LVCR         0x0020
+#define   IMX21LCDC_LVCR_V_WIDTH       GENMASK(31, 26)
+#define   IMX21LCDC_LVCR_V_BPORCH      GENMASK(7, 0)
+#define   IMX21LCDC_LVCR_V_FPORCH      GENMASK(15, 8)
+
+/* LCDC Panning Offset Register */
+#define IMX21LCDC_LPOR         0x0024
+
+/* LCDC Sharp Configuration Register */
+#define IMX21LCDC_LSCR         0x0028
+
+/* LCDC PWM Contrast Control Register */
+#define IMX21LCDC_LPCCR                0x002c
+
+/* LCDC DMA Control Register */
+#define IMX21LCDC_LDCR         0x0030
+
+/* LCDC Refresh Mode Control Register */
+#define IMX21LCDC_LRMCR                0x0034
+
+/* LCDC Interrupt Configuration Register */
+#define IMX21LCDC_LICR         0x0038
+
+/* LCDC Interrupt Enable Register */
+#define IMX21LCDC_LIER         0x003c
+#define   IMX21LCDC_LIER_EOF           BIT(1)
+
+/* LCDC Interrupt Status Register */
+#define IMX21LCDC_LISR         0x0040
+#define   IMX21LCDC_LISR_EOF           BIT(1)
+
+/* LCDC Graphic Window Start Address Register */
+#define IMX21LCDC_LGWSAR       0x0050
+
+/* LCDC Graph Window Size Register */
+#define IMX21LCDC_LGWSR                0x0054
+
+/* LCDC Graphic Window Virtual Page Width Register */
+#define IMX21LCDC_LGWVPWR      0x0058
+
+/* LCDC Graphic Window Panning Offset Register */
+#define IMX21LCDC_LGWPOR       0x005c
+
+/* LCDC Graphic Window Position Register */
+#define IMX21LCDC_LGWPR                0x0060
+
+/* LCDC Graphic Window Control Register */
+#define IMX21LCDC_LGWCR                0x0064
+
+/* LCDC Graphic Window DMA Control Register */
+#define IMX21LCDC_LGWDCR       0x0068
+
+/* LCDC AUS Mode Control Register */
+#define IMX21LCDC_LAUSCR       0x0080
+
+/* LCDC AUS Mode Cursor Control Register */
+#define IMX21LCDC_LAUSCCR      0x0084
+
+/* Background Lookup Table */
+#define IMX21LCDC_BGLUT                0x0800
+
+/* Graphic Window Lookup Table */
+#define IMX21LCDC_GWLUT                0x0c00
+
+#define BPP_RGB565 0x05
+
+#define LCDC_MIN_XRES 64
+#define LCDC_MIN_YRES 64
+
+#define LCDC_MAX_XRES 1024
+#define LCDC_MAX_YRES 1024
+
+struct imx_lcdc {
+       struct drm_device drm;
+       struct drm_simple_display_pipe pipe;
+       const struct drm_display_mode *mode;
+       struct drm_connector connector;
+       struct drm_panel *panel;
+       struct drm_bridge *bridge;
+       void __iomem *base;
+
+       struct clk *clk_ipg;
+       struct clk *clk_ahb;
+       struct clk *clk_per;
+};
+
+static const u32 imx_lcdc_formats[] = {
+       DRM_FORMAT_RGB565,
+};
+
+static inline struct imx_lcdc *drm_to_lcdc(struct drm_device *drm)
+{
+       return container_of(drm, struct imx_lcdc, drm);
+}
+
+static unsigned int imx_lcdc_get_format(unsigned int drm_format)
+{
+       unsigned int bpp;
+
+       switch (drm_format) {
+       default:
+               DRM_WARN("Format not supported - fallback to RGB565\n");
+               fallthrough;
+       case DRM_FORMAT_RGB565:
+               bpp = BPP_RGB565;
+               break;
+       }
+
+       return bpp;
+}
+
+static int imx_lcdc_connector_get_modes(struct drm_connector *connector)
+{
+       struct imx_lcdc *lcdc = drm_to_lcdc(connector->dev);
+
+       if (lcdc->panel)
+               return drm_panel_get_modes(lcdc->panel, connector);
+
+       return 0;
+}
+
+static const struct drm_connector_helper_funcs imx_lcdc_connector_hfuncs = {
+       .get_modes = imx_lcdc_connector_get_modes,
+};
+
+static const struct drm_connector_funcs imx_lcdc_connector_funcs = {
+       .reset = drm_atomic_helper_connector_reset,
+       .fill_modes = drm_helper_probe_single_connector_modes,
+       .destroy = drm_connector_cleanup,
+       .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+       .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static void imx_lcdc_update_hw_registers(struct drm_simple_display_pipe *pipe,
+                                        struct drm_plane_state *old_state,
+                                        bool mode_set)
+{
+       struct drm_crtc *crtc = &pipe->crtc;
+       struct drm_plane_state *new_state = pipe->plane.state;
+       struct drm_framebuffer *fb = new_state->fb;
+       struct imx_lcdc *lcdc = drm_to_lcdc(pipe->crtc.dev);
+       unsigned int bpp = imx_lcdc_get_format(fb->format->format);
+       unsigned int lvcr; /* LVCR-Register value */
+       unsigned int lhcr; /* LHCR-Register value */
+       unsigned int framesize;
+       dma_addr_t addr = drm_fb_cma_get_gem_addr(fb, new_state, 0);
+
+       /* The LSSAR register specifies the LCD screen start address (SSA). */
+       writel(addr, lcdc->base + IMX21LCDC_LSSAR);
+
+       if (!mode_set)
+               return;
+
+       /* Disable PER clock to make register write possible */
+       if (old_state && old_state->crtc && old_state->crtc->enabled)
+               clk_disable_unprepare(lcdc->clk_per);
+
+       /* Framesize */
+       framesize = FIELD_PREP(IMX21LCDC_LSR_XMAX, crtc->mode.hdisplay / 16);
+       framesize |= FIELD_PREP(IMX21LCDC_LSR_YMAX, crtc->mode.vdisplay);
+       writel(framesize, lcdc->base + IMX21LCDC_LSR);
+
+       /* HSYNC */
+       lhcr = FIELD_PREP(IMX21LCDC_LHCR_H_FPORCH, crtc->mode.hsync_start - 
crtc->mode.hdisplay - 1);
+       lhcr |= FIELD_PREP(IMX21LCDC_LHCR_H_WIDTH, crtc->mode.hsync_end - 
crtc->mode.hsync_start - 1);
+       lhcr |= FIELD_PREP(IMX21LCDC_LHCR_H_BPORCH, crtc->mode.htotal - 
crtc->mode.hsync_end - 3);
+       writel(lhcr, lcdc->base + IMX21LCDC_LHCR);
+
+       /* VSYNC */
+       lvcr = FIELD_PREP(IMX21LCDC_LVCR_V_FPORCH, crtc->mode.vsync_start - 
crtc->mode.vdisplay);
+       lvcr |= FIELD_PREP(IMX21LCDC_LVCR_V_WIDTH, crtc->mode.vsync_end - 
crtc->mode.vsync_start);
+       lvcr |= FIELD_PREP(IMX21LCDC_LVCR_V_BPORCH, crtc->mode.vtotal - 
crtc->mode.vsync_end);
+       writel(lvcr, lcdc->base + IMX21LCDC_LVCR);
+
+       writel(readl(lcdc->base + IMX21LCDC_LPCR) | 
FIELD_PREP(IMX21LCDC_LPCR_BPIX, bpp),
+              lcdc->base + IMX21LCDC_LPCR);
+
+       /* Virtual Page Width */
+       writel(new_state->fb->pitches[0] / 4, lcdc->base + IMX21LCDC_LVPWR);
+
+       /* Enable PER clock */
+       if (new_state->crtc->enabled)
+               clk_prepare_enable(lcdc->clk_per);
+}
+
+static void imx_lcdc_pipe_enable(struct drm_simple_display_pipe *pipe,
+                                struct drm_crtc_state *crtc_state,
+                                struct drm_plane_state *plane_state)
+{
+       int ret;
+       int clk_div;
+       int bpp;
+       struct imx_lcdc *lcdc = drm_to_lcdc(pipe->crtc.dev);
+       struct drm_display_mode *mode = &pipe->crtc.mode;
+       struct drm_display_info *disp_info = &pipe->connector->display_info;
+       const int hsync_pol = (mode->flags & DRM_MODE_FLAG_PHSYNC) ? 0 : 1;
+       const int vsync_pol = (mode->flags & DRM_MODE_FLAG_PVSYNC) ? 0 : 1;
+       const int data_enable_pol =
+               (disp_info->bus_flags & DRM_BUS_FLAG_DE_HIGH) ? 0 : 1;
+       const int clk_pol =
+               (disp_info->bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE) ? 0 
: 1;
+
+       drm_panel_prepare(lcdc->panel);
+
+       clk_div = DIV_ROUND_CLOSEST_ULL(clk_get_rate(lcdc->clk_per),
+                                       mode->clock * 1000);
+       bpp = imx_lcdc_get_format(plane_state->fb->format->format);
+
+       writel(FIELD_PREP(IMX21LCDC_LPCR_PCD, clk_div - 1) |
+              FIELD_PREP(IMX21LCDC_LPCR_LPPOL, hsync_pol) |
+              FIELD_PREP(IMX21LCDC_LPCR_FLMPOL, vsync_pol) |
+              FIELD_PREP(IMX21LCDC_LPCR_OEPOL, data_enable_pol) |
+              FIELD_PREP(IMX21LCDC_LPCR_TFT, 1) |
+              FIELD_PREP(IMX21LCDC_LPCR_COLOR, 1) |
+              FIELD_PREP(IMX21LCDC_LPCR_PBSIZ, 3) |
+              FIELD_PREP(IMX21LCDC_LPCR_BPIX, bpp) |
+              FIELD_PREP(IMX21LCDC_LPCR_SCLKSEL, 1) |
+              FIELD_PREP(IMX21LCDC_LPCR_PIXPOL, 0) |
+              FIELD_PREP(IMX21LCDC_LPCR_CLKPOL, clk_pol),
+              lcdc->base + IMX21LCDC_LPCR);
+
+       /* 0px panning offset */
+       writel(0x0, lcdc->base + IMX21LCDC_LPOR);
+
+       /* disable hardware cursor */
+       writel(readl(lcdc->base + IMX21LCDC_LCPR) & ~IMX21LCDC_LCPR_CC,
+              lcdc->base + IMX21LCDC_LCPR);
+
+       ret = clk_prepare_enable(lcdc->clk_ipg);
+       if (ret) {
+               dev_err(pipe->crtc.dev->dev, "Cannot enable ipg clock: %pe\n", 
ERR_PTR(ret));
+               return;
+       }
+       ret = clk_prepare_enable(lcdc->clk_ahb);
+       if (ret) {
+               dev_err(pipe->crtc.dev->dev, "Cannot enable ahb clock: %pe\n", 
ERR_PTR(ret));
+               clk_disable_unprepare(lcdc->clk_ipg);
+               return;
+       }
+
+       imx_lcdc_update_hw_registers(pipe, NULL, true);
+       drm_panel_enable(lcdc->panel);
+
+       /* Enable VBLANK Interrupt */
+       writel(IMX21LCDC_LIER_EOF, lcdc->base + IMX21LCDC_LIER);
+}
+
+static void imx_lcdc_pipe_disable(struct drm_simple_display_pipe *pipe)
+{
+       struct imx_lcdc *lcdc = drm_to_lcdc(pipe->crtc.dev);
+       struct drm_panel *panel = lcdc->panel;
+       struct drm_crtc *crtc = &lcdc->pipe.crtc;
+       struct drm_pending_vblank_event *event;
+
+       drm_panel_disable(panel);
+
+       clk_disable_unprepare(lcdc->clk_ahb);
+       clk_disable_unprepare(lcdc->clk_ipg);
+
+       if (pipe->crtc.enabled)
+               clk_disable_unprepare(lcdc->clk_per);
+
+       drm_panel_unprepare(panel);
+
+       spin_lock_irq(&lcdc->drm.event_lock);
+       event = crtc->state->event;
+       if (event) {
+               crtc->state->event = NULL;
+               drm_crtc_send_vblank_event(crtc, event);
+       }
+       spin_unlock_irq(&lcdc->drm.event_lock);
+
+       /* Disable VBLANK Interrupt */
+       writel(0, lcdc->base + IMX21LCDC_LIER);
+}
+
+static int imx_lcdc_pipe_check(struct drm_simple_display_pipe *pipe,
+                              struct drm_plane_state *plane_state,
+                              struct drm_crtc_state *crtc_state)
+{
+       const struct drm_display_mode *mode = &crtc_state->mode;
+
+       if ((mode->hdisplay < LCDC_MIN_XRES || mode->hdisplay > LCDC_MAX_XRES) 
||
+           (mode->vdisplay < LCDC_MIN_YRES || mode->vdisplay > LCDC_MAX_YRES) 
||
+           (mode->hdisplay % 16)) {
+               DRM_ERROR("unsupported display mode (%u x %u)\n",
+                         mode->hdisplay, mode->vdisplay);
+               return -EINVAL;
+       }
+
+       if (!FIELD_FIT(IMX21LCDC_LHCR_H_FPORCH, mode->hsync_start - 
mode->hdisplay - 1) ||
+           !FIELD_FIT(IMX21LCDC_LHCR_H_WIDTH, mode->hsync_end - 
mode->hsync_start - 1) ||
+           !FIELD_FIT(IMX21LCDC_LHCR_H_BPORCH, mode->htotal - mode->hsync_end 
- 3)) {
+               DRM_ERROR("invalid HSYNC setting (htotal = %hu, hsync_start = 
%hu, hsync_end = %hu, hdisplay = %hu)\n",
+                         mode->htotal, mode->hsync_start, mode->hsync_end, 
mode->hdisplay);
+               return -EINVAL;
+       }
+       if (!FIELD_FIT(IMX21LCDC_LVCR_V_FPORCH, mode->vsync_start - 
mode->vdisplay) ||
+           !FIELD_FIT(IMX21LCDC_LVCR_V_WIDTH, mode->vsync_end - 
mode->vsync_start) ||
+           !FIELD_FIT(IMX21LCDC_LVCR_V_BPORCH, mode->vtotal - 
mode->vsync_end)) {
+               DRM_ERROR("invalid VSYNC setting (vtotal = %hu, vsync_start = 
%hu, vsync_end = %hu, vdisplay = %hu)\n",
+                         mode->vtotal, mode->vsync_start, mode->vsync_end, 
mode->vdisplay);
+               return -EINVAL;
+
+       }
+
+       if (plane_state->fb->pitches[0] % 4) {
+               DRM_ERROR("invalid pitches setting (%hu)\n", 
plane_state->fb->pitches[0]);
+               return -EINVAL;
+       }
+
+       crtc_state->mode_changed =
+               crtc_state->mode.hdisplay != pipe->crtc.state->mode.hdisplay ||
+               crtc_state->mode.vdisplay != pipe->crtc.state->mode.vdisplay ||
+               plane_state->fb->pitches[0] != 
pipe->plane.state->fb->pitches[0];
+
+       return 0;
+}
+
+static void imx_lcdc_pipe_update(struct drm_simple_display_pipe *pipe,
+                                struct drm_plane_state *old_state)
+{
+       struct drm_crtc *crtc = &pipe->crtc;
+       struct drm_pending_vblank_event *event = crtc->state->event;
+       struct drm_plane_state *new_state = pipe->plane.state;
+       struct drm_framebuffer *fb = new_state->fb;
+       struct drm_framebuffer *old_fb = old_state->fb;
+       struct drm_crtc *old_crtc = old_state->crtc;
+       bool mode_changed = false;
+
+       if (old_fb && old_fb->format != fb->format)
+               mode_changed = true;
+       else if (old_crtc != crtc)
+               mode_changed = true;
+       else if (crtc->state->mode_changed)
+               mode_changed = true;
+
+       imx_lcdc_update_hw_registers(pipe, old_state, mode_changed);
+
+       if (event) {
+               crtc->state->event = NULL;
+
+               spin_lock_irq(&crtc->dev->event_lock);
+
+               if (crtc->state->active && drm_crtc_vblank_get(crtc) == 0)
+                       drm_crtc_arm_vblank_event(crtc, event);
+               else
+                       drm_crtc_send_vblank_event(crtc, event);
+
+               spin_unlock_irq(&crtc->dev->event_lock);
+       }
+}
+
+static const struct drm_simple_display_pipe_funcs imx_lcdc_pipe_funcs = {
+       .enable = imx_lcdc_pipe_enable,
+       .disable = imx_lcdc_pipe_disable,
+       .check = imx_lcdc_pipe_check,
+       .update = imx_lcdc_pipe_update,
+       .prepare_fb = drm_gem_simple_display_pipe_prepare_fb,
+};
+
+static const struct drm_mode_config_funcs imx_lcdc_mode_config_funcs = {
+       .fb_create = drm_gem_fb_create_with_dirty,
+       .atomic_check = drm_atomic_helper_check,
+       .atomic_commit = drm_atomic_helper_commit,
+};
+
+static const struct drm_mode_config_helper_funcs imx_lcdc_mode_config_helpers 
= {
+       .atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,
+};
+
+DEFINE_DRM_GEM_CMA_FOPS(imx_lcdc_drm_fops);
+
+static struct drm_driver imx_lcdc_drm_driver = {
+       .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
+       .fops = &imx_lcdc_drm_fops,
+       DRM_GEM_CMA_DRIVER_OPS_VMAP,
+       .name = "imx-lcdc",
+       .desc = "i.MX LCDC driver",
+       .date = "20200716",
+};
+
+static const struct of_device_id imx_lcdc_of_dev_id[] = {
+       { .compatible = "fsl,imx21-lcdc", },
+       { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx_lcdc_of_dev_id);
+
+static irqreturn_t irq_handler(int irq, void *arg)
+{
+       struct imx_lcdc *lcdc = (struct imx_lcdc *)arg;
+       struct drm_crtc *crtc = &lcdc->pipe.crtc;
+       unsigned int status;
+
+       status = readl(lcdc->base + IMX21LCDC_LISR);
+
+       if (status & IMX21LCDC_LISR_EOF) {
+               drm_crtc_handle_vblank(crtc);
+               return IRQ_HANDLED;
+       }
+
+       return IRQ_NONE;
+}
+
+static int imx_lcdc_probe(struct platform_device *pdev)
+{
+       struct imx_lcdc *lcdc;
+       struct drm_device *drm;
+       int irq;
+       int ret;
+       struct device *dev = &pdev->dev;
+
+       lcdc = devm_drm_dev_alloc(&pdev->dev, &imx_lcdc_drm_driver,
+                                 struct imx_lcdc, drm);
+       if (!lcdc)
+               return -ENOMEM;
+
+       drm = &lcdc->drm;
+
+       lcdc->base = devm_platform_ioremap_resource(pdev, 0);
+       if (IS_ERR(lcdc->base))
+               return PTR_ERR(lcdc->base);
+
+       /* Panel */
+       ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, &lcdc->panel, 
&lcdc->bridge);
+       if (ret)
+               return dev_err_probe(dev, ret, "Failed to find panel or 
bridge\n");
+
+       /* Get Clocks */
+       lcdc->clk_ipg = devm_clk_get(dev, "ipg");
+       if (IS_ERR(lcdc->clk_ipg))
+               return dev_err_probe(dev, PTR_ERR(lcdc->clk_ipg), "Failed to 
get ipg clk\n");
+
+       lcdc->clk_ahb = devm_clk_get(dev, "ahb");
+       if (IS_ERR(lcdc->clk_ahb))
+               return dev_err_probe(dev, PTR_ERR(lcdc->clk_ipg), "Failed to 
get ahb clk\n");
+
+       lcdc->clk_per = devm_clk_get(dev, "per");
+       if (IS_ERR(lcdc->clk_per))
+               return dev_err_probe(dev, PTR_ERR(lcdc->clk_ipg), "Failed to 
get ahb clk\n");
+
+       ret = dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32));
+       if (ret)
+               return dev_err_probe(drm->dev, ret, "Failed to set DMA 
Mask.\n");
+
+       /* Modeset init */
+       ret = drmm_mode_config_init(drm);
+       if (ret)
+               return dev_err_probe(drm->dev, ret, "Failed to initialized mode 
setting.\n");
+
+       /* CRTC, Plane, Encoder */
+       ret = drm_simple_display_pipe_init(drm, &lcdc->pipe, 
&imx_lcdc_pipe_funcs, imx_lcdc_formats,
+                                          ARRAY_SIZE(imx_lcdc_formats), NULL, 
&lcdc->connector);
+       if (ret < 0)
+               return dev_err_probe(drm->dev, ret, "Cannot setup simple 
display pipe\n");
+
+       ret = drm_vblank_init(drm, drm->mode_config.num_crtc);
+       if (ret < 0)
+               return dev_err_probe(drm->dev, ret, "Failed to initialize 
vblank\n");
+
+       if (lcdc->bridge) {
+               ret = drm_simple_display_pipe_attach_bridge(&lcdc->pipe,
+                                                           lcdc->bridge);
+               if (ret)
+                       return dev_err_probe(drm->dev, ret, "Cannot connect 
bridge\n");
+       }
+
+       /* Connector */
+       drm_connector_helper_add(&lcdc->connector, &imx_lcdc_connector_hfuncs);
+       drm_connector_init(drm, &lcdc->connector, &imx_lcdc_connector_funcs,
+                          DRM_MODE_CONNECTOR_DPI);
+
+       /*
+        * The LCDC controller does not have an enable bit. The
+        * controller starts directly when the clocks are enabled.
+        * If the clocks are enabled when the controller is not yet
+        * programmed with proper register values (enabled at the
+        * bootloader, for example) then it just goes into some undefined
+        * state.
+        * To avoid this issue, let's enable and disable LCDC IPG,
+        * PER and AHB clock so that we force some kind of 'reset'
+        * to the LCDC block.
+        */
+
+       ret = clk_prepare_enable(lcdc->clk_ipg);
+       if (ret)
+               return dev_err_probe(dev, ret, "Cannot enable ipg clock\n");
+       clk_disable_unprepare(lcdc->clk_ipg);
+
+       ret = clk_prepare_enable(lcdc->clk_per);
+       if (ret)
+               return dev_err_probe(dev, ret, "Cannot enable per clock\n");
+       clk_disable_unprepare(lcdc->clk_per);
+
+       ret = clk_prepare_enable(lcdc->clk_ahb);
+       if (ret)
+               return dev_err_probe(dev, ret, "Cannot enable ahb clock\n");
+       clk_disable_unprepare(lcdc->clk_ahb);
+
+       drm->mode_config.min_width = LCDC_MIN_XRES;
+       drm->mode_config.max_width = LCDC_MAX_XRES;
+       drm->mode_config.min_height = LCDC_MIN_YRES;
+       drm->mode_config.max_height = LCDC_MAX_YRES;
+       drm->mode_config.preferred_depth = 16;
+       drm->mode_config.funcs = &imx_lcdc_mode_config_funcs;
+       drm->mode_config.helper_private = &imx_lcdc_mode_config_helpers;
+
+       drm_mode_config_reset(drm);
+
+       irq = platform_get_irq(pdev, 0);
+       if (irq < 0) {
+               ret = irq;
+               return ret;
+       }
+
+       ret = devm_request_irq(dev, irq, irq_handler, 0, "imx-lcdc", lcdc);
+       if (ret < 0)
+               return dev_err_probe(drm->dev, ret, "Failed to install IRQ 
handler\n");
+
+       platform_set_drvdata(pdev, drm);
+
+       ret = drm_dev_register(&lcdc->drm, 0);
+       if (ret)
+               return dev_err_probe(dev, ret, "Cannot register device\n");
+
+       drm_fbdev_generic_setup(drm, 0);
+
+       return 0;
+}
+
+static int imx_lcdc_remove(struct platform_device *pdev)
+{
+       struct imx_lcdc *lcdc = drm_to_lcdc(platform_get_drvdata(pdev));
+
+       drm_dev_unregister(&lcdc->drm);
+       drm_atomic_helper_shutdown(&lcdc->drm);
+
+       return 0;
+}
+
+static void imx_lcdc_shutdown(struct platform_device *pdev)
+{
+       drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
+}
+
+static struct platform_driver imx_lcdc_driver = {
+       .driver = {
+               .name = "imx-lcdc",
+               .of_match_table = imx_lcdc_of_dev_id,
+       },
+       .probe = imx_lcdc_probe,
+       .remove = imx_lcdc_remove,
+       .shutdown = imx_lcdc_shutdown,
+};
+module_platform_driver(imx_lcdc_driver);
+
+MODULE_AUTHOR("Marian Cichy <[email protected]>");
+MODULE_DESCRIPTION("Freescale i.MX LCDC driver");
+MODULE_LICENSE("GPL");
-- 
2.34.1

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