drm/komeda: Add komeda_crtc_prepare/unprepare

These two function will be used by komeda_crtc_enable/disable to do some
prepartion works when enable/disable a crtc. like enable a crtc:
  1. Adjust display operation mode.
  2. Enable/prepare needed clk.

v2: Rebase

Signed-off-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>

drivers/gpu/drm/arm/display/komeda/d71/d71_dev.c

@@ -243,6 +243,37 @@ static int d71_disable_irq(struct komeda_dev *mdev)
 	return 0;
 }
 
+static int to_d71_opmode(int core_mode)
+{
+	switch (core_mode) {
+	case KOMEDA_MODE_DISP0:
+		return DO0_ACTIVE_MODE;
+	case KOMEDA_MODE_DISP1:
+		return DO1_ACTIVE_MODE;
+	case KOMEDA_MODE_DUAL_DISP:
+		return DO01_ACTIVE_MODE;
+	case KOMEDA_MODE_INACTIVE:
+		return INACTIVE_MODE;
+	default:
+		WARN(1, "Unknown operation mode");
+		return INACTIVE_MODE;
+	}
+}
+
+static int d71_change_opmode(struct komeda_dev *mdev, int new_mode)
+{
+	struct d71_dev *d71 = mdev->chip_data;
+	u32 opmode = to_d71_opmode(new_mode);
+	int ret;
+
+	malidp_write32_mask(d71->gcu_addr, BLK_CONTROL, 0x7, opmode);
+
+	ret = dp_wait_cond(((malidp_read32(d71->gcu_addr, BLK_CONTROL) & 0x7) == opmode),
+			   100, 1000, 10000);
+
+	return ret > 0 ? 0 : -ETIMEDOUT;
+}
+
 static void d71_flush(struct komeda_dev *mdev,
 		      int master_pipe, u32 active_pipes)
 {
@@ -469,6 +500,7 @@ static struct komeda_dev_funcs d71_chip_funcs = {
 	.irq_handler	= d71_irq_handler,
 	.enable_irq	= d71_enable_irq,
 	.disable_irq	= d71_disable_irq,
+	.change_opmode	= d71_change_opmode,
 	.flush		= d71_flush,
 };
 

drivers/gpu/drm/arm/display/komeda/komeda_crtc.c

@@ -44,6 +44,110 @@ komeda_crtc_atomic_check(struct drm_crtc *crtc,
 	return 0;
 }
 
+u32 komeda_calc_mclk(struct komeda_crtc_state *kcrtc_st)
+{
+	unsigned long mclk = kcrtc_st->base.adjusted_mode.clock * 1000;
+
+	return mclk;
+}
+
+/* For active a crtc, mainly need two parts of preparation
+ * 1. adjust display operation mode.
+ * 2. enable needed clk
+ */
+int
+komeda_crtc_prepare(struct komeda_crtc *kcrtc)
+{
+	struct komeda_dev *mdev = kcrtc->base.dev->dev_private;
+	struct komeda_pipeline *master = kcrtc->master;
+	struct komeda_crtc_state *kcrtc_st = to_kcrtc_st(kcrtc->base.state);
+	unsigned long pxlclk_rate = kcrtc_st->base.adjusted_mode.clock * 1000;
+	u32 new_mode;
+	int err;
+
+	mutex_lock(&mdev->lock);
+
+	new_mode = mdev->dpmode | BIT(master->id);
+	if (WARN_ON(new_mode == mdev->dpmode)) {
+		err = 0;
+		goto unlock;
+	}
+
+	err = mdev->funcs->change_opmode(mdev, new_mode);
+	if (err) {
+		DRM_ERROR("failed to change opmode: 0x%x -> 0x%x.\n,",
+			  mdev->dpmode, new_mode);
+		goto unlock;
+	}
+
+	mdev->dpmode = new_mode;
+	/* Only need to enable mclk on single display mode, but no need to
+	 * enable mclk it on dual display mode, since the dual mode always
+	 * switch from single display mode, the mclk already enabled, no need
+	 * to enable it again.
+	 */
+	if (new_mode != KOMEDA_MODE_DUAL_DISP) {
+		err = clk_set_rate(mdev->mclk, komeda_calc_mclk(kcrtc_st));
+		if (err)
+			DRM_ERROR("failed to set mclk.\n");
+		err = clk_prepare_enable(mdev->mclk);
+		if (err)
+			DRM_ERROR("failed to enable mclk.\n");
+	}
+
+	err = clk_prepare_enable(master->aclk);
+	if (err)
+		DRM_ERROR("failed to enable axi clk for pipe%d.\n", master->id);
+	err = clk_set_rate(master->pxlclk, pxlclk_rate);
+	if (err)
+		DRM_ERROR("failed to set pxlclk for pipe%d\n", master->id);
+	err = clk_prepare_enable(master->pxlclk);
+	if (err)
+		DRM_ERROR("failed to enable pxl clk for pipe%d.\n", master->id);
+
+unlock:
+	mutex_unlock(&mdev->lock);
+
+	return err;
+}
+
+int
+komeda_crtc_unprepare(struct komeda_crtc *kcrtc)
+{
+	struct komeda_dev *mdev = kcrtc->base.dev->dev_private;
+	struct komeda_pipeline *master = kcrtc->master;
+	u32 new_mode;
+	int err;
+
+	mutex_lock(&mdev->lock);
+
+	new_mode = mdev->dpmode & (~BIT(master->id));
+
+	if (WARN_ON(new_mode == mdev->dpmode)) {
+		err = 0;
+		goto unlock;
+	}
+
+	err = mdev->funcs->change_opmode(mdev, new_mode);
+	if (err) {
+		DRM_ERROR("failed to change opmode: 0x%x -> 0x%x.\n,",
+			  mdev->dpmode, new_mode);
+		goto unlock;
+	}
+
+	mdev->dpmode = new_mode;
+
+	clk_disable_unprepare(master->pxlclk);
+	clk_disable_unprepare(master->aclk);
+	if (new_mode == KOMEDA_MODE_INACTIVE)
+		clk_disable_unprepare(mdev->mclk);
+
+unlock:
+	mutex_unlock(&mdev->lock);
+
+	return err;
+}
+
 void komeda_crtc_handle_event(struct komeda_crtc   *kcrtc,
 			      struct komeda_events *evts)
 {

drivers/gpu/drm/arm/display/komeda/komeda_dev.c

@@ -151,6 +151,8 @@ struct komeda_dev *komeda_dev_create(struct device *dev)
 	if (!mdev)
 		return ERR_PTR(-ENOMEM);
 
+	mutex_init(&mdev->lock);
+
 	mdev->dev = dev;
 	mdev->reg_base = devm_ioremap_resource(dev, io_res);
 	if (IS_ERR(mdev->reg_base)) {

drivers/gpu/drm/arm/display/komeda/komeda_dev.h

@@ -106,11 +106,34 @@ struct komeda_dev_funcs {
 
 	/** @dump_register: Optional, dump registers to seq_file */
 	void (*dump_register)(struct komeda_dev *mdev, struct seq_file *seq);
+	/**
+	 * @change_opmode:
+	 *
+	 * Notify HW to switch to a new display operation mode.
+	 */
+	int (*change_opmode)(struct komeda_dev *mdev, int new_mode);
 	/** @flush: Notify the HW to flush or kickoff the update */
 	void (*flush)(struct komeda_dev *mdev,
 		      int master_pipe, u32 active_pipes);
 };
 
+/**
+ * DISPLAY_MODE describes how many display been enabled, and which will be
+ * passed to CHIP by &komeda_dev_funcs->change_opmode(), then CHIP can do the
+ * pipeline resources assignment according to this usage hint.
+ * -   KOMEDA_MODE_DISP0: Only one display enabled, pipeline-0 work as master.
+ * -   KOMEDA_MODE_DISP1: Only one display enabled, pipeline-0 work as master.
+ * -   KOMEDA_MODE_DUAL_DISP: Dual display mode, both display has been enabled.
+ * And D71 supports assign two pipelines to one single display on mode
+ * KOMEDA_MODE_DISP0/DISP1
+ */
+enum {
+	KOMEDA_MODE_INACTIVE	= 0,
+	KOMEDA_MODE_DISP0	= BIT(0),
+	KOMEDA_MODE_DISP1	= BIT(1),
+	KOMEDA_MODE_DUAL_DISP	= KOMEDA_MODE_DISP0 | KOMEDA_MODE_DISP1,
+};
+
 /**
  * struct komeda_dev
  *
@@ -133,6 +156,9 @@ struct komeda_dev {
 	/** @irq: irq number */
 	int irq;
 
+	struct mutex lock; /* used to protect dpmode */
+	u32 dpmode; /* current display mode */
+
 	int n_pipelines;
 	struct komeda_pipeline *pipelines[KOMEDA_MAX_PIPELINES];