drm/msm/mdp5: Add MDSS top level driver

SoCs that contain MDP5 have a top level wrapper called MDSS that manages
clocks, power and irq for the sub-blocks within it.

Currently, the MDSS portions are stuffed into the MDP5 driver. This makes
it hard to represent the DT bindings in the correct way. We create a top
level MDSS helper that handles these parts. This is essentially moving out
some of the mdp5_kms irq code and MDSS register space and keeping it as a
separate entity. We haven't given any clocks to the top level MDSS yet,
but a AHB clock would be added in the future to access registers.

One thing to note is that the resources allocated by this helper are
tied to the top level platform_device (the one that allocates the
drm_device struct too). This device would be the parent to MDSS
sub-blocks like MDP5, DSI, eDP etc.

Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/Makefile

@@ -35,6 +35,7 @@ msm-y := \
 	mdp/mdp5/mdp5_crtc.o \
 	mdp/mdp5/mdp5_encoder.o \
 	mdp/mdp5/mdp5_irq.o \
+	mdp/mdp5/mdp5_mdss.o \
 	mdp/mdp5/mdp5_kms.o \
 	mdp/mdp5/mdp5_plane.o \
 	mdp/mdp5/mdp5_smp.o \

drivers/gpu/drm/msm/mdp/mdp5/mdp5_mdss.c

@@ -0,0 +1,223 @@
+/*
+ * Copyright (c) 2016, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/irqdomain.h>
+#include <linux/irq.h>
+
+#include "msm_drv.h"
+#include "mdp5_kms.h"
+
+/*
+ * If needed, this can become more specific: something like struct mdp5_mdss,
+ * which contains a 'struct msm_mdss base' member.
+ */
+struct msm_mdss {
+	struct drm_device *dev;
+
+	void __iomem *mmio, *vbif;
+
+	struct regulator *vdd;
+
+	struct {
+		volatile unsigned long enabled_mask;
+		struct irq_domain *domain;
+	} irqcontroller;
+};
+
+static inline void mdss_write(struct msm_mdss *mdss, u32 reg, u32 data)
+{
+	msm_writel(data, mdss->mmio + reg);
+}
+
+static inline u32 mdss_read(struct msm_mdss *mdss, u32 reg)
+{
+	return msm_readl(mdss->mmio + reg);
+}
+
+static irqreturn_t mdss_irq(int irq, void *arg)
+{
+	struct msm_mdss *mdss = arg;
+	u32 intr;
+
+	intr = mdss_read(mdss, REG_MDSS_HW_INTR_STATUS);
+
+	VERB("intr=%08x", intr);
+
+	while (intr) {
+		irq_hw_number_t hwirq = fls(intr) - 1;
+
+		generic_handle_irq(irq_find_mapping(
+				mdss->irqcontroller.domain, hwirq));
+		intr &= ~(1 << hwirq);
+	}
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * interrupt-controller implementation, so sub-blocks (MDP/HDMI/eDP/DSI/etc)
+ * can register to get their irq's delivered
+ */
+
+#define VALID_IRQS  (MDSS_HW_INTR_STATUS_INTR_MDP | \
+		MDSS_HW_INTR_STATUS_INTR_DSI0 | \
+		MDSS_HW_INTR_STATUS_INTR_DSI1 | \
+		MDSS_HW_INTR_STATUS_INTR_HDMI | \
+		MDSS_HW_INTR_STATUS_INTR_EDP)
+
+static void mdss_hw_mask_irq(struct irq_data *irqd)
+{
+	struct msm_mdss *mdss = irq_data_get_irq_chip_data(irqd);
+
+	smp_mb__before_atomic();
+	clear_bit(irqd->hwirq, &mdss->irqcontroller.enabled_mask);
+	smp_mb__after_atomic();
+}
+
+static void mdss_hw_unmask_irq(struct irq_data *irqd)
+{
+	struct msm_mdss *mdss = irq_data_get_irq_chip_data(irqd);
+
+	smp_mb__before_atomic();
+	set_bit(irqd->hwirq, &mdss->irqcontroller.enabled_mask);
+	smp_mb__after_atomic();
+}
+
+static struct irq_chip mdss_hw_irq_chip = {
+	.name		= "mdss",
+	.irq_mask	= mdss_hw_mask_irq,
+	.irq_unmask	= mdss_hw_unmask_irq,
+};
+
+static int mdss_hw_irqdomain_map(struct irq_domain *d, unsigned int irq,
+				 irq_hw_number_t hwirq)
+{
+	struct msm_mdss *mdss = d->host_data;
+
+	if (!(VALID_IRQS & (1 << hwirq)))
+		return -EPERM;
+
+	irq_set_chip_and_handler(irq, &mdss_hw_irq_chip, handle_level_irq);
+	irq_set_chip_data(irq, mdss);
+
+	return 0;
+}
+
+static struct irq_domain_ops mdss_hw_irqdomain_ops = {
+	.map = mdss_hw_irqdomain_map,
+	.xlate = irq_domain_xlate_onecell,
+};
+
+
+static int mdss_irq_domain_init(struct msm_mdss *mdss)
+{
+	struct device *dev = mdss->dev->dev;
+	struct irq_domain *d;
+
+	d = irq_domain_add_linear(dev->of_node, 32, &mdss_hw_irqdomain_ops,
+				  mdss);
+	if (!d) {
+		dev_err(dev, "mdss irq domain add failed\n");
+		return -ENXIO;
+	}
+
+	mdss->irqcontroller.enabled_mask = 0;
+	mdss->irqcontroller.domain = d;
+
+	return 0;
+}
+
+void msm_mdss_destroy(struct drm_device *dev)
+{
+	struct msm_drm_private *priv = dev->dev_private;
+	struct msm_mdss *mdss = priv->mdss;
+
+	if (!mdss)
+		return;
+
+	irq_domain_remove(mdss->irqcontroller.domain);
+	mdss->irqcontroller.domain = NULL;
+
+	regulator_disable(mdss->vdd);
+}
+
+int msm_mdss_init(struct drm_device *dev)
+{
+	struct platform_device *pdev = dev->platformdev;
+	struct msm_drm_private *priv = dev->dev_private;
+	struct msm_mdss *mdss;
+	int ret;
+
+	DBG("");
+
+	if (!of_device_is_compatible(dev->dev->of_node, "qcom,mdss"))
+		return 0;
+
+	mdss = devm_kzalloc(dev->dev, sizeof(*mdss), GFP_KERNEL);
+	if (!mdss) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	mdss->dev = dev;
+
+	mdss->mmio = msm_ioremap(pdev, "mdss_phys", "MDSS");
+	if (IS_ERR(mdss->mmio)) {
+		ret = PTR_ERR(mdss->mmio);
+		goto fail;
+	}
+
+	mdss->vbif = msm_ioremap(pdev, "vbif_phys", "VBIF");
+	if (IS_ERR(mdss->vbif)) {
+		ret = PTR_ERR(mdss->vbif);
+		goto fail;
+	}
+
+	/* Regulator to enable GDSCs in downstream kernels */
+	mdss->vdd = devm_regulator_get(dev->dev, "vdd");
+	if (IS_ERR(mdss->vdd)) {
+		ret = PTR_ERR(mdss->vdd);
+		goto fail;
+	}
+
+	ret = regulator_enable(mdss->vdd);
+	if (ret) {
+		dev_err(dev->dev, "failed to enable regulator vdd: %d\n",
+			ret);
+		goto fail;
+	}
+
+	ret = devm_request_irq(dev->dev, platform_get_irq(pdev, 0),
+			       mdss_irq, 0, "mdss_isr", mdss);
+	if (ret) {
+		dev_err(dev->dev, "failed to init irq: %d\n", ret);
+		goto fail_irq;
+	}
+
+	ret = mdss_irq_domain_init(mdss);
+	if (ret) {
+		dev_err(dev->dev, "failed to init sub-block irqs: %d\n", ret);
+		goto fail_irq;
+	}
+
+	priv->mdss = mdss;
+
+	return 0;
+fail_irq:
+	regulator_disable(mdss->vdd);
+fail:
+	return ret;
+}

drivers/gpu/drm/msm/msm_drv.h

@@ -46,6 +46,7 @@
 struct msm_kms;
 struct msm_gpu;
 struct msm_mmu;
+struct msm_mdss;
 struct msm_rd_state;
 struct msm_perf_state;
 struct msm_gem_submit;
@@ -82,6 +83,9 @@ struct msm_drm_private {
 	/* subordinate devices, if present: */
 	struct platform_device *gpu_pdev;
 
+	/* top level MDSS wrapper device (for MDP5 only) */
+	struct msm_mdss *mdss;
+
 	/* possibly this should be in the kms component, but it is
 	 * shared by both mdp4 and mdp5..
 	 */

drivers/gpu/drm/msm/msm_kms.h

@@ -73,5 +73,7 @@ static inline void msm_kms_init(struct msm_kms *kms,
 
 struct msm_kms *mdp4_kms_init(struct drm_device *dev);
 struct msm_kms *mdp5_kms_init(struct drm_device *dev);
+int msm_mdss_init(struct drm_device *dev);
+void msm_mdss_destroy(struct drm_device *dev);
 
 #endif /* __MSM_KMS_H__ */