drm/kmb: Add support for KeemBay Display

This is a basic KMS atomic modesetting display driver for KeemBay family of
SOCs. Driver has no 2D or 3D graphics. It calls into the ADV bridge
driver at the connector level.

Single CRTC with LCD controller->mipi DSI->ADV bridge

Only 1080p resolution and single plane is supported at this time.

v2: moved extern to .h, removed license text
    use drm_dev_init, upclassed dev_private, removed HAVE_IRQ.(Sam)

v3: Squashed all 59 commits to one

v4: review changes from Sam Ravnborg
	renamed dev_p to kmb
	moved clocks under kmb_clock, consolidated clk initializations
	use drmm functions
	use DRM_GEM_CMA_DRIVER_OPS_VMAP

v5: corrected spellings
v6: corrected checkpatch warnings
v7: review changes Sam Ravnborg and Thomas Zimmerman
	removed kmb_crtc.h kmb_crtc_cleanup (Thomas)
	renamed mode_set, kmb_load, inlined unload (Thomas)
	moved remaining logging to drm_*(Thomas)
	re-orged driver initialization (Thomas)
	moved plane_status to drm_private (Sam)
	removed unnecessary logs and defines and ifdef codes (Sam)
	call helper_check in plane_atomic_check (Sam)
	renamed set to get for bpp and format functions(Sam)
	use drm helper functions for reset, duplicate/destroy state instead
	of kmb functions (Sam)
	removed kmb_priv from kmb_plane and removed kmb_plane_state (Sam)
v8: get clk_pll0 from display node in dt
v9: moved csc_coef_lcd to plane.c (Daniel Vetter)
    call drm_atomic_helper_shutdown in remove (Daniel V)
    use drm_crtc_handle_vblank (Daniel V)
    renamed kmb_dsi_hw_init to kmb_dsi_mode_set (Daniel V)
    complimentary changes to device tree changes (Rob)
v10: call drm_crtc_arm_vblank_event in atomic_flush (Daniel V)
     moved global vars to kmb_private and added locks (Daniel V)
     changes in driver to accommodate changes in DT to separate DSI
     entries (Sam R)
     review changes to separate mipi DSI (Sam R)
v11: review changes to separate msscam (Neil A,Sam R)
v12: fixed warnings Reported-by: kernel test robot <lkp@intel.com>

Signed-off-by: Anitha Chrisanthus <anitha.chrisanthus@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1604538931-26726-6-git-send-email-anitha.chrisanthus@intel.com

drivers/gpu/drm/kmb/kmb_crtc.c

@@ -0,0 +1,214 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright © 2018-2020 Intel Corporation
+ */
+
+#include <linux/clk.h>
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_print.h>
+#include <drm/drm_vblank.h>
+#include <drm/drm_modeset_helper_vtables.h>
+
+#include "kmb_drv.h"
+#include "kmb_dsi.h"
+#include "kmb_plane.h"
+#include "kmb_regs.h"
+
+struct kmb_crtc_timing {
+	u32 vfront_porch;
+	u32 vback_porch;
+	u32 vsync_len;
+	u32 hfront_porch;
+	u32 hback_porch;
+	u32 hsync_len;
+};
+
+static int kmb_crtc_enable_vblank(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct kmb_drm_private *kmb = to_kmb(dev);
+
+	/* Clear interrupt */
+	kmb_write_lcd(kmb, LCD_INT_CLEAR, LCD_INT_VERT_COMP);
+	/* Set which interval to generate vertical interrupt */
+	kmb_write_lcd(kmb, LCD_VSTATUS_COMPARE,
+		      LCD_VSTATUS_COMPARE_VSYNC);
+	/* Enable vertical interrupt */
+	kmb_set_bitmask_lcd(kmb, LCD_INT_ENABLE,
+			    LCD_INT_VERT_COMP);
+	return 0;
+}
+
+static void kmb_crtc_disable_vblank(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct kmb_drm_private *kmb = to_kmb(dev);
+
+	/* Clear interrupt */
+	kmb_write_lcd(kmb, LCD_INT_CLEAR, LCD_INT_VERT_COMP);
+	/* Disable vertical interrupt */
+	kmb_clr_bitmask_lcd(kmb, LCD_INT_ENABLE,
+			    LCD_INT_VERT_COMP);
+}
+
+static const struct drm_crtc_funcs kmb_crtc_funcs = {
+	.destroy = drm_crtc_cleanup,
+	.set_config = drm_atomic_helper_set_config,
+	.page_flip = drm_atomic_helper_page_flip,
+	.reset = drm_atomic_helper_crtc_reset,
+	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
+	.enable_vblank = kmb_crtc_enable_vblank,
+	.disable_vblank = kmb_crtc_disable_vblank,
+};
+
+static void kmb_crtc_set_mode(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_display_mode *m = &crtc->state->adjusted_mode;
+	struct kmb_crtc_timing vm;
+	struct kmb_drm_private *kmb = to_kmb(dev);
+	unsigned int val = 0;
+
+	/* Initialize mipi */
+	kmb_dsi_mode_set(kmb->kmb_dsi, m, kmb->sys_clk_mhz);
+	drm_info(dev,
+		 "vfp= %d vbp= %d vsyc_len=%d hfp=%d hbp=%d hsync_len=%d\n",
+		 m->crtc_vsync_start - m->crtc_vdisplay,
+		 m->crtc_vtotal - m->crtc_vsync_end,
+		 m->crtc_vsync_end - m->crtc_vsync_start,
+		 m->crtc_hsync_start - m->crtc_hdisplay,
+		 m->crtc_htotal - m->crtc_hsync_end,
+		 m->crtc_hsync_end - m->crtc_hsync_start);
+	val = kmb_read_lcd(kmb, LCD_INT_ENABLE);
+	kmb_clr_bitmask_lcd(kmb, LCD_INT_ENABLE, val);
+	kmb_set_bitmask_lcd(kmb, LCD_INT_CLEAR, ~0x0);
+	vm.vfront_porch = 2;
+	vm.vback_porch = 2;
+	vm.vsync_len = 8;
+	vm.hfront_porch = 0;
+	vm.hback_porch = 0;
+	vm.hsync_len = 28;
+
+	drm_dbg(dev, "%s : %dactive height= %d vbp=%d vfp=%d vsync-w=%d h-active=%d h-bp=%d h-fp=%d hysnc-l=%d",
+		__func__, __LINE__,
+			m->crtc_vdisplay, vm.vback_porch, vm.vfront_porch,
+			vm.vsync_len, m->crtc_hdisplay, vm.hback_porch,
+			vm.hfront_porch, vm.hsync_len);
+	kmb_write_lcd(kmb, LCD_V_ACTIVEHEIGHT,
+		      m->crtc_vdisplay - 1);
+	kmb_write_lcd(kmb, LCD_V_BACKPORCH, vm.vback_porch);
+	kmb_write_lcd(kmb, LCD_V_FRONTPORCH, vm.vfront_porch);
+	kmb_write_lcd(kmb, LCD_VSYNC_WIDTH, vm.vsync_len - 1);
+	kmb_write_lcd(kmb, LCD_H_ACTIVEWIDTH,
+		      m->crtc_hdisplay - 1);
+	kmb_write_lcd(kmb, LCD_H_BACKPORCH, vm.hback_porch);
+	kmb_write_lcd(kmb, LCD_H_FRONTPORCH, vm.hfront_porch);
+	kmb_write_lcd(kmb, LCD_HSYNC_WIDTH, vm.hsync_len - 1);
+	/* This is hardcoded as 0 in the Myriadx code */
+	kmb_write_lcd(kmb, LCD_VSYNC_START, 0);
+	kmb_write_lcd(kmb, LCD_VSYNC_END, 0);
+	/* Back ground color */
+	kmb_write_lcd(kmb, LCD_BG_COLOUR_LS, 0x4);
+	if (m->flags == DRM_MODE_FLAG_INTERLACE) {
+		kmb_write_lcd(kmb,
+			      LCD_VSYNC_WIDTH_EVEN, vm.vsync_len - 1);
+		kmb_write_lcd(kmb,
+			      LCD_V_BACKPORCH_EVEN, vm.vback_porch);
+		kmb_write_lcd(kmb,
+			      LCD_V_FRONTPORCH_EVEN, vm.vfront_porch);
+		kmb_write_lcd(kmb, LCD_V_ACTIVEHEIGHT_EVEN,
+			      m->crtc_vdisplay - 1);
+		/* This is hardcoded as 10 in the Myriadx code */
+		kmb_write_lcd(kmb, LCD_VSYNC_START_EVEN, 10);
+		kmb_write_lcd(kmb, LCD_VSYNC_END_EVEN, 10);
+	}
+	kmb_write_lcd(kmb, LCD_TIMING_GEN_TRIG, 1);
+	kmb_set_bitmask_lcd(kmb, LCD_CONTROL, LCD_CTRL_ENABLE);
+	kmb_set_bitmask_lcd(kmb, LCD_INT_ENABLE, val);
+}
+
+static void kmb_crtc_atomic_enable(struct drm_crtc *crtc,
+				   struct drm_atomic_state *state)
+{
+	struct kmb_drm_private *kmb = crtc_to_kmb_priv(crtc);
+
+	clk_prepare_enable(kmb->kmb_clk.clk_lcd);
+	kmb_crtc_set_mode(crtc);
+	drm_crtc_vblank_on(crtc);
+}
+
+static void kmb_crtc_atomic_disable(struct drm_crtc *crtc,
+				    struct drm_atomic_state *state)
+{
+	struct kmb_drm_private *kmb = crtc_to_kmb_priv(crtc);
+	struct drm_crtc_state *old_state = drm_atomic_get_old_crtc_state(state, crtc);
+
+	/* due to hw limitations, planes need to be off when crtc is off */
+	drm_atomic_helper_disable_planes_on_crtc(old_state, false);
+
+	drm_crtc_vblank_off(crtc);
+	clk_disable_unprepare(kmb->kmb_clk.clk_lcd);
+}
+
+static void kmb_crtc_atomic_begin(struct drm_crtc *crtc,
+				  struct drm_atomic_state *state)
+{
+	struct drm_device *dev = crtc->dev;
+	struct kmb_drm_private *kmb = to_kmb(dev);
+
+	kmb_clr_bitmask_lcd(kmb, LCD_INT_ENABLE,
+			    LCD_INT_VERT_COMP);
+}
+
+static void kmb_crtc_atomic_flush(struct drm_crtc *crtc,
+				  struct drm_atomic_state *state)
+{
+	struct drm_device *dev = crtc->dev;
+	struct kmb_drm_private *kmb = to_kmb(dev);
+
+	kmb_set_bitmask_lcd(kmb, LCD_INT_ENABLE,
+			    LCD_INT_VERT_COMP);
+
+	spin_lock_irq(&crtc->dev->event_lock);
+	if (crtc->state->event) {
+		if (drm_crtc_vblank_get(crtc) == 0)
+			drm_crtc_arm_vblank_event(crtc, crtc->state->event);
+		else
+			drm_crtc_send_vblank_event(crtc, crtc->state->event);
+	}
+	crtc->state->event = NULL;
+	spin_unlock_irq(&crtc->dev->event_lock);
+}
+
+static const struct drm_crtc_helper_funcs kmb_crtc_helper_funcs = {
+	.atomic_begin = kmb_crtc_atomic_begin,
+	.atomic_enable = kmb_crtc_atomic_enable,
+	.atomic_disable = kmb_crtc_atomic_disable,
+	.atomic_flush = kmb_crtc_atomic_flush,
+};
+
+int kmb_setup_crtc(struct drm_device *drm)
+{
+	struct kmb_drm_private *kmb = to_kmb(drm);
+	struct kmb_plane *primary;
+	int ret;
+
+	primary = kmb_plane_init(drm);
+	if (IS_ERR(primary))
+		return PTR_ERR(primary);
+
+	ret = drm_crtc_init_with_planes(drm, &kmb->crtc, &primary->base_plane,
+					NULL, &kmb_crtc_funcs, NULL);
+	if (ret) {
+		kmb_plane_destroy(&primary->base_plane);
+		return ret;
+	}
+
+	drm_crtc_helper_add(&kmb->crtc, &kmb_crtc_helper_funcs);
+	return 0;
+}