blob: c578095b09a53e89cc5777da7bcd800eac25ac03 [file] [log] [blame]
// 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/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <drm/drm_color_mgmt.h>
#include "rcar_cmm.h"
#define CM2_LUT_CTRL 0x0000
#define CM2_LUT_CTRL_LUT_EN BIT(0)
#define CM2_LUT_TBL_BASE 0x0600
#define CM2_LUT_TBL(__i) (CM2_LUT_TBL_BASE + (__i) * 4)
struct rcar_cmm {
void __iomem *base;
/*
* @lut: 1D-LUT state
* @lut.enabled: 1D-LUT enabled flag
*/
struct {
bool enabled;
} 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);
}
/*
* rcar_cmm_lut_write() - Scale the DRM LUT table entries to hardware precision
* and write to the CMM registers
* @rcmm: Pointer to the CMM device
* @drm_lut: Pointer to the DRM LUT table
*/
static void rcar_cmm_lut_write(struct rcar_cmm *rcmm,
const struct drm_color_lut *drm_lut)
{
unsigned int i;
for (i = 0; i < CM2_LUT_SIZE; ++i) {
u32 entry = drm_color_lut_extract(drm_lut[i].red, 8) << 16
| drm_color_lut_extract(drm_lut[i].green, 8) << 8
| drm_color_lut_extract(drm_lut[i].blue, 8);
rcar_cmm_write(rcmm, CM2_LUT_TBL(i), entry);
}
}
/*
* rcar_cmm_setup() - Configure the CMM unit
* @pdev: The platform device associated with the CMM instance
* @config: The CMM unit configuration
*
* Configure the CMM unit with the given configuration. Currently enabling,
* disabling and programming of the 1-D LUT unit is supported.
*
* As rcar_cmm_setup() accesses the CMM registers the unit should be powered
* and its functional clock enabled. To guarantee this, before any call to
* this function is made, the CMM unit has to be enabled by calling
* rcar_cmm_enable() first.
*
* TODO: Add support for LUT double buffer operations to avoid updating the
* LUT table entries while a frame is being displayed.
*/
int rcar_cmm_setup(struct platform_device *pdev,
const struct rcar_cmm_config *config)
{
struct rcar_cmm *rcmm = platform_get_drvdata(pdev);
/* Disable LUT if no table is provided. */
if (!config->lut.table) {
if (rcmm->lut.enabled) {
rcar_cmm_write(rcmm, CM2_LUT_CTRL, 0);
rcmm->lut.enabled = false;
}
return 0;
}
/* Enable LUT and program the new gamma table values. */
if (!rcmm->lut.enabled) {
rcar_cmm_write(rcmm, CM2_LUT_CTRL, CM2_LUT_CTRL_LUT_EN);
rcmm->lut.enabled = true;
}
rcar_cmm_lut_write(rcmm, config->lut.table);
return 0;
}
EXPORT_SYMBOL_GPL(rcar_cmm_setup);
/*
* rcar_cmm_enable() - Enable the CMM unit
* @pdev: The platform device associated with the CMM instance
*
* When the output of the corresponding DU channel is routed to the CMM unit,
* the unit shall be enabled before the DU channel is started, and remain
* enabled until the channel is stopped. The CMM unit shall be disabled with
* rcar_cmm_disable().
*
* Calls to rcar_cmm_enable() and rcar_cmm_disable() are not reference-counted.
* It is an error to attempt to enable an already enabled CMM unit, or to
* attempt to disable a disabled unit.
*/
int rcar_cmm_enable(struct platform_device *pdev)
{
int ret;
ret = pm_runtime_get_sync(&pdev->dev);
if (ret < 0)
return ret;
return 0;
}
EXPORT_SYMBOL_GPL(rcar_cmm_enable);
/*
* rcar_cmm_disable() - Disable the CMM unit
* @pdev: The platform device associated with the CMM instance
*
* See rcar_cmm_enable() for usage information.
*
* Disabling the CMM unit disable all the internal processing blocks. The CMM
* state shall thus be restored with rcar_cmm_setup() when re-enabling the CMM
* unit after the next rcar_cmm_enable() call.
*/
void rcar_cmm_disable(struct platform_device *pdev)
{
struct rcar_cmm *rcmm = platform_get_drvdata(pdev);
rcar_cmm_write(rcmm, CM2_LUT_CTRL, 0);
rcmm->lut.enabled = false;
pm_runtime_put(&pdev->dev);
}
EXPORT_SYMBOL_GPL(rcar_cmm_disable);
/*
* rcar_cmm_init() - Initialize the CMM unit
* @pdev: The platform device associated with the CMM instance
*
* Return: 0 on success, -EPROBE_DEFER if the CMM is not available yet,
* -ENODEV if the DRM_RCAR_CMM config option is disabled
*/
int rcar_cmm_init(struct platform_device *pdev)
{
struct rcar_cmm *rcmm = platform_get_drvdata(pdev);
if (!rcmm)
return -EPROBE_DEFER;
return 0;
}
EXPORT_SYMBOL_GPL(rcar_cmm_init);
static int rcar_cmm_probe(struct platform_device *pdev)
{
struct rcar_cmm *rcmm;
rcmm = devm_kzalloc(&pdev->dev, sizeof(*rcmm), GFP_KERNEL);
if (!rcmm)
return -ENOMEM;
platform_set_drvdata(pdev, rcmm);
rcmm->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(rcmm->base))
return PTR_ERR(rcmm->base);
pm_runtime_enable(&pdev->dev);
return 0;
}
static int rcar_cmm_remove(struct platform_device *pdev)
{
pm_runtime_disable(&pdev->dev);
return 0;
}
static const struct of_device_id rcar_cmm_of_table[] = {
{ .compatible = "renesas,rcar-gen3-cmm", },
{ .compatible = "renesas,rcar-gen2-cmm", },
{ },
};
MODULE_DEVICE_TABLE(of, rcar_cmm_of_table);
static struct platform_driver rcar_cmm_platform_driver = {
.probe = rcar_cmm_probe,
.remove = rcar_cmm_remove,
.driver = {
.name = "rcar-cmm",
.of_match_table = rcar_cmm_of_table,
},
};
module_platform_driver(rcar_cmm_platform_driver);
MODULE_AUTHOR("Jacopo Mondi <jacopo+renesas@jmondi.org>");
MODULE_DESCRIPTION("Renesas R-Car CMM Driver");
MODULE_LICENSE("GPL v2");