Re: [PATCH 07/14] drm/imx: dc: Add DPR channel support

On 09/19/2025, Frank Li wrote:

On Fri, Jul 04, 2025 at 05:03:54PM +0800, Liu Ying wrote:

quoted

Display Prefetch Resolve Channel(DPRC) is a part of a prefetch engine.
It fetches display data, transforms it to linear format and stores it
to DPRC's RTRAM.  PRG, as the other part of a prefetch engine, acts as
a gasket between the RTRAM controller and a FetchUnit.  Add a platform
driver to support the DPRC.

Signed-off-by: Liu Ying <victor.liu@nxp.com>
---
 drivers/gpu/drm/imx/dc/Kconfig   |   1 +
 drivers/gpu/drm/imx/dc/Makefile  |   6 +-
 drivers/gpu/drm/imx/dc/dc-dprc.c | 499 +++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/imx/dc/dc-dprc.h |  35 +++
 drivers/gpu/drm/imx/dc/dc-drv.c  |   1 +
 drivers/gpu/drm/imx/dc/dc-drv.h  |   1 +
 drivers/gpu/drm/imx/dc/dc-prg.c  |  12 +
 drivers/gpu/drm/imx/dc/dc-prg.h  |   4 +
 8 files changed, 556 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/imx/dc/Kconfig b/drivers/gpu/drm/imx/dc/Kconfig
index 415993207f2e3487f09602050fa9284fd0955cc7..507dc9a92d96be225cd9b10968a037dad286b327 100644
--- a/drivers/gpu/drm/imx/dc/Kconfig
+++ b/drivers/gpu/drm/imx/dc/Kconfig

...

quoted

+		return false;
+
+	if (!dc_prg_stride_supported(dprc->prg, prg_stride, baddr))
+		return false;
+
+	return true;
+}
+
+static int dc_dprc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct resource *res;
+	void __iomem *base;
+	struct dc_dprc *dprc;
+	int ret, wrap_irq;

If have new version, try keep reverse christmas tree order for nice look.

Ack.

quoted

+
+	dprc = devm_kzalloc(dev, sizeof(*dprc), GFP_KERNEL);
+	if (!dprc)
+		return -ENOMEM;
+
+	ret = imx_scu_get_handle(&dprc->ipc_handle);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to get SCU ipc handle\n");
+
+	base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	dprc->reg = devm_regmap_init_mmio(dev, base, &dc_dprc_regmap_config);
+	if (IS_ERR(dprc->reg))
+		return PTR_ERR(dprc->reg);
+
+	wrap_irq = platform_get_irq_byname(pdev, "dpr_wrap");
+	if (wrap_irq < 0)
+		return -ENODEV;
+
+	dprc->clk_apb = devm_clk_get(dev, "apb");
+	if (IS_ERR(dprc->clk_apb))
+		return dev_err_probe(dev, PTR_ERR(dprc->clk_apb),
+				     "failed to get APB clock\n");
+
+	dprc->clk_b = devm_clk_get(dev, "b");
+	if (IS_ERR(dprc->clk_b))
+		return dev_err_probe(dev, PTR_ERR(dprc->clk_b),
+				     "failed to get B clock\n");
+
+	dprc->clk_rtram = devm_clk_get(dev, "rtram");
+	if (IS_ERR(dprc->clk_rtram))
+		return dev_err_probe(dev, PTR_ERR(dprc->clk_rtram),
+				     "failed to get RTRAM clock\n");

use clk bulk API will simple clock handlers code, include suspend/resume
codes.

Ack.

Frank

quoted

+
+	ret = of_property_read_u32(np, "fsl,sc-resource", &dprc->sc_resource);
+	if (ret) {
+		dev_err(dev, "failed to get SC resource %d\n", ret);
+		return ret;
+	}
+
+	dprc->prg = dc_prg_lookup_by_phandle(dev, "fsl,prgs", 0);
+	if (!dprc->prg)
+		return dev_err_probe(dev, -EPROBE_DEFER,
+				     "failed to lookup PRG\n");
+
+	dc_prg_set_dprc(dprc->prg, dprc);
+
+	dprc->dev = dev;
+	spin_lock_init(&dprc->lock);
+
+	ret = devm_request_irq(dev, wrap_irq, dc_dprc_wrap_irq_handler,
+			       IRQF_SHARED, dev_name(dev), dprc);
+	if (ret < 0) {
+		dev_err(dev, "failed to request dpr_wrap IRQ(%d): %d\n",
+			wrap_irq, ret);
+		return ret;
+	}
+
+	dev_set_drvdata(dev, dprc);
+
+	ret = devm_pm_runtime_enable(dev);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to enable PM runtime\n");
+
+	return 0;
+}
+
+static int dc_dprc_runtime_suspend(struct device *dev)
+{
+	struct dc_dprc *dprc = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(dprc->clk_rtram);
+	clk_disable_unprepare(dprc->clk_b);
+	clk_disable_unprepare(dprc->clk_apb);
+
+	return 0;
+}
+
+static int dc_dprc_runtime_resume(struct device *dev)
+{
+	struct dc_dprc *dprc = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(dprc->clk_apb);
+	if (ret) {
+		dev_err(dev, "failed to enable APB clock: %d\n", ret);
+		goto err1;
+	}
+
+	ret = clk_prepare_enable(dprc->clk_b);
+	if (ret) {
+		dev_err(dev, "failed to enable B clock: %d\n", ret);
+		goto err2;
+	}
+
+	ret = clk_prepare_enable(dprc->clk_rtram);
+	if (ret) {
+		dev_err(dev, "failed to enable RTRAM clock: %d\n", ret);
+		goto err3;
+	}
+
+	dc_dprc_reset(dprc);
+
+	/* disable all control IRQs and enable all error IRQs */
+	guard(spinlock_irqsave)(&dprc->lock);
+	regmap_write(dprc->reg, IRQ_MASK, IRQ_CTRL_MASK);
+
+	return 0;
+err3:
+	clk_disable_unprepare(dprc->clk_b);
+err2:
+	clk_disable_unprepare(dprc->clk_apb);
+err1:
+	return ret;
+}
+
+static const struct dev_pm_ops dc_dprc_pm_ops = {
+	RUNTIME_PM_OPS(dc_dprc_runtime_suspend, dc_dprc_runtime_resume, NULL)
+};
+
+static const struct of_device_id dc_dprc_dt_ids[] = {
+	{ .compatible = "fsl,imx8qxp-dpr-channel", },
+	{ /* sentinel */ }
+};
+
+struct platform_driver dc_dprc_driver = {
+	.probe = dc_dprc_probe,
+	.driver = {
+		.name = "imx8-dc-dpr-channel",
+		.suppress_bind_attrs = true,
+		.of_match_table = dc_dprc_dt_ids,
+		.pm = pm_ptr(&dc_dprc_pm_ops),
+	},
+};

diff --git a/drivers/gpu/drm/imx/dc/dc-dprc.h b/drivers/gpu/drm/imx/dc/dc-dprc.h
new file mode 100644
index 0000000000000000000000000000000000000000..f977858b57fec2f19775a97dc0baf011ca177c0b
--- /dev/null
+++ b/drivers/gpu/drm/imx/dc/dc-dprc.h

@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2025 NXP
+ */
+
+#ifndef __DC_DPRC_H__
+#define __DC_DPRC_H__
+
+#include <linux/device.h>
+#include <linux/types.h>
+
+#include <drm/drm_fourcc.h>
+
+struct dc_dprc;
+
+void dc_dprc_configure(struct dc_dprc *dprc, unsigned int stream_id,
+		       unsigned int width, unsigned int height,
+		       unsigned int stride,
+		       const struct drm_format_info *format,
+		       dma_addr_t baddr, bool start);
+
+void dc_dprc_disable_repeat_en(struct dc_dprc *dprc);
+
+void dc_dprc_disable(struct dc_dprc *dprc);
+
+void dc_dprc_disable_at_boot(struct dc_dprc *dprc);
+
+bool dc_dprc_rtram_width_supported(struct dc_dprc *dprc, unsigned int width);
+
+bool dc_dprc_stride_supported(struct dc_dprc *dprc,
+			      unsigned int stride, unsigned int width,
+			      const struct drm_format_info *format,
+			      dma_addr_t baddr);
+
+#endif

diff --git a/drivers/gpu/drm/imx/dc/dc-drv.c b/drivers/gpu/drm/imx/dc/dc-drv.c
index 9bdcfc5aee976ef77bea6b3f6f3ac5f11249798f..17b9c4d0953d46be0a2cd276f06298d848fdcbdd 100644
--- a/drivers/gpu/drm/imx/dc/dc-drv.c
+++ b/drivers/gpu/drm/imx/dc/dc-drv.c

@@ -269,6 +269,7 @@ static struct platform_driver dc_driver = {
 static struct platform_driver * const dc_drivers[] = {
 	&dc_cf_driver,
 	&dc_de_driver,
+	&dc_dprc_driver,
 	&dc_ed_driver,
 	&dc_fg_driver,
 	&dc_fl_driver,

diff --git a/drivers/gpu/drm/imx/dc/dc-drv.h b/drivers/gpu/drm/imx/dc/dc-drv.h
index 557e7d90e4ea8ca2af59027b3152163cf7f9a618..93a8ce4e7c314770b64ccb631628b7e79648c791 100644
--- a/drivers/gpu/drm/imx/dc/dc-drv.h
+++ b/drivers/gpu/drm/imx/dc/dc-drv.h

@@ -74,6 +74,7 @@ int dc_plane_init(struct dc_drm_device *dc_drm, struct dc_plane *dc_plane);

 extern struct platform_driver dc_cf_driver;
 extern struct platform_driver dc_de_driver;
+extern struct platform_driver dc_dprc_driver;
 extern struct platform_driver dc_ed_driver;
 extern struct platform_driver dc_fg_driver;
 extern struct platform_driver dc_fl_driver;

diff --git a/drivers/gpu/drm/imx/dc/dc-prg.c b/drivers/gpu/drm/imx/dc/dc-prg.c
index 9a1a312c0aeebf47bcf50ffa77971aa3bb431a12..bb6c47133e90f9bc5eb3fb0e30c3f338ec82213b 100644
--- a/drivers/gpu/drm/imx/dc/dc-prg.c
+++ b/drivers/gpu/drm/imx/dc/dc-prg.c

@@ -19,6 +19,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>

+#include "dc-dprc.h"
 #include "dc-prg.h"

 #define SET			0x4

@@ -63,6 +64,7 @@ struct dc_prg {
 	struct list_head list;
 	struct clk *clk_apb;
 	struct clk *clk_rtram;
+	struct dc_dprc *dprc;
 };

 static DEFINE_MUTEX(dc_prg_list_mutex);

@@ -217,6 +219,16 @@ dc_prg_lookup_by_phandle(struct device *dev, const char *name, int index)
 	return NULL;
 }

+void dc_prg_set_dprc(struct dc_prg *prg, struct dc_dprc *dprc)
+{
+	prg->dprc = dprc;
+}
+
+struct dc_dprc *dc_prg_get_dprc(struct dc_prg *prg)
+{
+	return prg->dprc;
+}
+
 static int dc_prg_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;

diff --git a/drivers/gpu/drm/imx/dc/dc-prg.h b/drivers/gpu/drm/imx/dc/dc-prg.h
index 6fd9b050bfa12334720f83ff9ceaf337e3048a54..f29d154f7de597b9d20d5e71303049f6f8b022d6 100644
--- a/drivers/gpu/drm/imx/dc/dc-prg.h
+++ b/drivers/gpu/drm/imx/dc/dc-prg.h

@@ -32,4 +32,8 @@ bool dc_prg_stride_supported(struct dc_prg *prg,
 struct dc_prg *
 dc_prg_lookup_by_phandle(struct device *dev, const char *name, int index);

+void dc_prg_set_dprc(struct dc_prg *prg, struct dc_dprc *dprc);
+
+struct dc_dprc *dc_prg_get_dprc(struct dc_prg *prg);
+
 #endif

--

2.34.1

-- 
Regards,
Liu Ying