Hi Jacopo,
Now that I've read the whole series, here are a few comments.
On Fri, Jun 07, 2019 at 02:35:40PM +0300, Laurent Pinchart wrote:
Hi Jacopo,
Thank you for the patch.
On Thu, Jun 06, 2019 at 04:22:14PM +0200, Jacopo Mondi wrote:
Add a driver for the R-Car Display Unit Color Correction Module.
Each DU output channel is provided with a CMM unit to perform image enhancement and color correction.
I would say "On most Gen3 SoCs, each DU ..." as V3* SoCs have no CMM.
Add support for CMM through a driver that supports configuration of the 1-dimensional LUT table. More advanced CMM feature could be implemented on top of this basic one.
s/could be/will be/ ? :-)
Signed-off-by: Jacopo Mondi jacopo+renesas@jmondi.org
drivers/gpu/drm/rcar-du/Kconfig | 7 + drivers/gpu/drm/rcar-du/Makefile | 1 + drivers/gpu/drm/rcar-du/rcar_cmm.c | 197 +++++++++++++++++++++++++++++ drivers/gpu/drm/rcar-du/rcar_cmm.h | 38 ++++++ 4 files changed, 243 insertions(+) create mode 100644 drivers/gpu/drm/rcar-du/rcar_cmm.c create mode 100644 drivers/gpu/drm/rcar-du/rcar_cmm.h
diff --git a/drivers/gpu/drm/rcar-du/Kconfig b/drivers/gpu/drm/rcar-du/Kconfig index 1529849e217e..539d232790d1 100644 --- a/drivers/gpu/drm/rcar-du/Kconfig +++ b/drivers/gpu/drm/rcar-du/Kconfig @@ -13,6 +13,13 @@ config DRM_RCAR_DU Choose this option if you have an R-Car chipset. If M is selected the module will be called rcar-du-drm.
+config DRM_RCAR_CMM
- bool "R-Car DU Color Management Module (CMM) Support"
- depends on DRM && OF
- depends on DRM_RCAR_DU
- help
Enable support for R-Car Color Management Module (CMM).config DRM_RCAR_DW_HDMI tristate "R-Car DU Gen3 HDMI Encoder Support" depends on DRM && OF diff --git a/drivers/gpu/drm/rcar-du/Makefile b/drivers/gpu/drm/rcar-du/Makefile index 6c2ed9c46467..4d1187ccc3e5 100644 --- a/drivers/gpu/drm/rcar-du/Makefile +++ b/drivers/gpu/drm/rcar-du/Makefile @@ -15,6 +15,7 @@ rcar-du-drm-$(CONFIG_DRM_RCAR_LVDS) += rcar_du_of.o \ rcar-du-drm-$(CONFIG_DRM_RCAR_VSP) += rcar_du_vsp.o rcar-du-drm-$(CONFIG_DRM_RCAR_WRITEBACK) += rcar_du_writeback.o
+obj-$(CONFIG_DRM_RCAR_CMM) += rcar_cmm.o obj-$(CONFIG_DRM_RCAR_DU) += rcar-du-drm.o obj-$(CONFIG_DRM_RCAR_DW_HDMI) += rcar_dw_hdmi.o obj-$(CONFIG_DRM_RCAR_LVDS) += rcar_lvds.o diff --git a/drivers/gpu/drm/rcar-du/rcar_cmm.c b/drivers/gpu/drm/rcar-du/rcar_cmm.c new file mode 100644 index 000000000000..5d9d917b91f4 --- /dev/null +++ b/drivers/gpu/drm/rcar-du/rcar_cmm.c @@ -0,0 +1,197 @@ +// SPDX-License-Identifier: GPL-2.0 +/*
- rcar_cmm.c -- R-Car Display Unit Color Management Module
- Copyright (C) 2019 Jacopo Mondi jacopo+renesas@jmondi.org
- */
+#include <linux/clk.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h>
+#include <drm/drm_atomic.h>
+#include "rcar_cmm.h"
+#define CM2_LUT_CTRL 0x00
I would write all register addresses with 3 (or 4) digits.
+#define CM2_LUT_CTRL_EN BIT(0) +#define CM2_LUT_TBLA 0x600
I would define this as
#define CM2_LUT_TBLA(n) (0x600 + (n) * 4)
+struct rcar_cmm {
- struct clk *clk;
- void __iomem *base;
- bool enabled;
- /* LUT table scratch buffer. */
- struct {
bool restore;unsigned int size;uint32_t table[CMM_GAMMA_LUT_SIZE];- } lut;
+};
+static inline int rcar_cmm_read(struct rcar_cmm *rcmm, u32 reg) +{
- return ioread32(rcmm->base + reg);
+}
+static inline void rcar_cmm_write(struct rcar_cmm *rcmm, u32 reg, u32 data) +{
- iowrite32(data, rcmm->base + reg);
+}
+int rcar_cmm_setup(struct platform_device *pdev, struct rcar_cmm_config *config)
Please document the functions exposed to the DU driver. It's hard to understand the setup vs. enable/disable split by just reading this driver.
+{
- struct rcar_cmm *rcmm = platform_get_drvdata(pdev);
- unsigned int i;
- if (config->lut.size > CMM_GAMMA_LUT_SIZE)
return -EINVAL;- /*
* As cmm_setup is called by atomic commit tail helper, it might be* called before the enabling the CRTC (which calls cmm_enable()).** Store the LUT table entries in the scratch buffer to be later* programmed at enable time.*/
I think we'll be able to simplify this once Kieran's DU group handling patches land. Let's see which series gets merged first :-)
- if (!rcmm->enabled) {
if (!config->lut.enable)return 0;for (i = 0; i < config->lut.size; ++i) {struct drm_color_lut *lut = &config->lut.table[i];rcmm->lut.table[i] = (lut->red & 0xff) << 16 |(lut->green & 0xff) << 8 |(lut->blue & 0xff);}rcmm->lut.restore = true;rcmm->lut.size = config->lut.size;return 0;- }
- if (rcar_cmm_read(rcmm, CM2_LUT_CTRL) & CM2_LUT_CTRL_EN &&
!config->lut.enable) {rcar_cmm_write(rcmm, CM2_LUT_CTRL, 0);return 0;- }
- /* Enable LUT and program the new gamma table values. */
- rcar_cmm_write(rcmm, CM2_LUT_CTRL, CM2_LUT_CTRL_EN);
Shouldn't you write the LUT contents before enabling it (same below) ?
- for (i = 0; i < config->lut.size; ++i) {
struct drm_color_lut *lut = &config->lut.table[i];u32 val = (lut->red & 0xff) << 16 | (lut->green & 0xff) << 8 |(lut->blue & 0xff);Do you need to recompute the value, can't you use rcmm->lut.table ?
rcar_cmm_write(rcmm, CM2_LUT_TBLA + i * 4, val);- }
- return 0;
+}
You need to export this and the next two functions.
+int rcar_cmm_enable(struct platform_device *pdev) +{
- struct rcar_cmm *rcmm = platform_get_drvdata(pdev);
What if this function gets called before the CMM is probed ? I think you need an equivalent to vsp1_du_init() to handle this.
- unsigned int i;
- int ret;
- if (rcmm->enabled)
return 0;Can this happen without a bug in the caller ? If it can, and assuming the caller balances the enable and disable calls, you will have unbalanced clk_prepare_enable() and clk_disable_unprepare() calls.
- ret = clk_prepare_enable(rcmm->clk);
- if (ret)
return ret;Could you use pm_runtime_get_sync() instead ?
- /* Apply the LUT table values saved at cmm_setup time. */
- if (rcmm->lut.restore) {
rcar_cmm_write(rcmm, CM2_LUT_CTRL, CM2_LUT_CTRL_EN);for (i = 0; i < rcmm->lut.size; ++i)rcar_cmm_write(rcmm, CM2_LUT_TBLA + i * 4,rcmm->lut.table[i]);rcmm->lut.restore = false;rcmm->lut.size = 0;- }
I would move this code to a separate function called by both rcar_cmm_setup() and rcar_cmm_enable().
- rcmm->enabled = true;
- return 0;
+}
+void rcar_cmm_disable(struct platform_device *pdev) +{
- struct rcar_cmm *rcmm = platform_get_drvdata(pdev);
- rcar_cmm_write(rcmm, CM2_LUT_CTRL, 0);
- clk_disable_unprepare(rcmm->clk);
- rcmm->lut.restore = false;
- rcmm->lut.size = 0;
- rcmm->enabled = false;
+}
+static int rcar_cmm_probe(struct platform_device *pdev) +{
- struct rcar_cmm *rcmm;
- struct resource *res;
- resource_size_t size;
- rcmm = devm_kzalloc(&pdev->dev, sizeof(*rcmm), GFP_KERNEL);
- if (!rcmm)
return -ENOMEM;- platform_set_drvdata(pdev, rcmm);
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- size = resource_size(res);
- if (!devm_request_mem_region(&pdev->dev, res->start, size,
dev_name(&pdev->dev))) {dev_err(&pdev->dev,"can't request region for resource %pR\n", res);return -EBUSY;- }
- rcmm->base = devm_ioremap_nocache(&pdev->dev, res->start, size);
- if (IS_ERR(rcmm->base))
return PTR_ERR(rcmm->base);Anything wrong with devm_ioremap_resource() ?
- rcmm->clk = devm_clk_get(&pdev->dev, NULL);
- if (IS_ERR(rcmm->clk)) {
dev_err(&pdev->dev, "Failed to get CMM clock");return PTR_ERR(rcmm->clk);- }
- rcmm->lut.restore = false;
- rcmm->lut.size = 0;
- rcmm->enabled = false;
As you allocate memory with kzalloc() you could skip this.
- return 0;
+}
+static const struct of_device_id rcar_cmm_of_table[] = {
- { .compatible = "renesas,cmm-gen3" },
- { .compatible = "renesas,cmm-gen2" },
- { },
+};
+MODULE_DEVICE_TABLE(of, rcar_cmm_of_table);
+static struct platform_driver rcar_cmm_platform_driver = {
- .probe = rcar_cmm_probe,
- .driver = {
.name = "rcar-cmm",.of_match_table = rcar_cmm_of_table,- },
No need for suspend/resume support ? The DU driver should disable/enable the CMM in its suspend/resume paths, so this should be fine, but won't the LUT contents be lost and need to be restored ?
+};
+module_platform_driver(rcar_cmm_platform_driver);
+MODULE_AUTHOR("Jacopo Mondi <jacopo+renesas@jmondi.org");
Missing >.
+MODULE_DESCRIPTION("Renesas R-Car CMM Driver"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/gpu/drm/rcar-du/rcar_cmm.h b/drivers/gpu/drm/rcar-du/rcar_cmm.h new file mode 100644 index 000000000000..da61a145dc5c --- /dev/null +++ b/drivers/gpu/drm/rcar-du/rcar_cmm.h @@ -0,0 +1,38 @@ +/* SPDX-License-Identifier: GPL-2.0+ */
The .c and .h file licenses don't match.
+/*
- rcar_cmm.h -- R-Car Display Unit Color Management Module
- Copyright (C) 2019 Jacopo Mondi jacopo+renesas@jmondi.org
- */
+#ifndef __RCAR_CMM_H__ +#define __RCAR_CMM_H__
+#include <linux/platform_device.h>
You can forward-declare struct platform_device instead.
+#define CMM_GAMMA_LUT_SIZE 256
+struct drm_color_lut;
+/**
- struct rcar_cmm_config - CMM configuration
- @lut: 1D-LUT configuration
- @lut.enable: 1D-LUT enable flag
- @lut.table: 1D-LUT table entries.
- @lut.size 1D-LUT number of entries. Max is 256
The last line is missing a colon.
- */
+struct rcar_cmm_config {
- struct {
bool enable;struct drm_color_lut *table;unsigned int size;- } lut;
+};
+int rcar_cmm_enable(struct platform_device *);
As the OF API looks up a struct device from a device_node, should we use struct device here ?
+void rcar_cmm_disable(struct platform_device *);
I find headers more readable when function arguments are named. In this case the types probably provide enough information, but good luck trying to read a function such as
int foo(int, int, bool);
+int rcar_cmm_setup(struct platform_device *, struct rcar_cmm_config *);
Can the second argument be const ?
+#endif /* __RCAR_CMM_H__ */
-- Regards,
Laurent Pinchart