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1// SPDX-License-Identifier: GPL-2.0+2/*3 * R-Car Display Unit Color Management Module4 *5 * Copyright (C) 2019 Jacopo Mondi <jacopo+renesas@jmondi.org>6 */7 8#include <linux/io.h>9#include <linux/module.h>10#include <linux/of.h>11#include <linux/platform_device.h>12#include <linux/pm_runtime.h>13 14#include <drm/drm_color_mgmt.h>15 16#include "rcar_cmm.h"17 18#define CM2_LUT_CTRL 0x000019#define CM2_LUT_CTRL_LUT_EN BIT(0)20#define CM2_LUT_TBL_BASE 0x060021#define CM2_LUT_TBL(__i) (CM2_LUT_TBL_BASE + (__i) * 4)22 23struct rcar_cmm {24 void __iomem *base;25 26 /*27 * @lut: 1D-LUT state28 * @lut.enabled: 1D-LUT enabled flag29 */30 struct {31 bool enabled;32 } lut;33};34 35static inline int rcar_cmm_read(struct rcar_cmm *rcmm, u32 reg)36{37 return ioread32(rcmm->base + reg);38}39 40static inline void rcar_cmm_write(struct rcar_cmm *rcmm, u32 reg, u32 data)41{42 iowrite32(data, rcmm->base + reg);43}44 45/*46 * rcar_cmm_lut_write() - Scale the DRM LUT table entries to hardware precision47 * and write to the CMM registers48 * @rcmm: Pointer to the CMM device49 * @drm_lut: Pointer to the DRM LUT table50 */51static void rcar_cmm_lut_write(struct rcar_cmm *rcmm,52 const struct drm_color_lut *drm_lut)53{54 unsigned int i;55 56 for (i = 0; i < CM2_LUT_SIZE; ++i) {57 u32 entry = drm_color_lut_extract(drm_lut[i].red, 8) << 1658 | drm_color_lut_extract(drm_lut[i].green, 8) << 859 | drm_color_lut_extract(drm_lut[i].blue, 8);60 61 rcar_cmm_write(rcmm, CM2_LUT_TBL(i), entry);62 }63}64 65/*66 * rcar_cmm_setup() - Configure the CMM unit67 * @pdev: The platform device associated with the CMM instance68 * @config: The CMM unit configuration69 *70 * Configure the CMM unit with the given configuration. Currently enabling,71 * disabling and programming of the 1-D LUT unit is supported.72 *73 * As rcar_cmm_setup() accesses the CMM registers the unit should be powered74 * and its functional clock enabled. To guarantee this, before any call to75 * this function is made, the CMM unit has to be enabled by calling76 * rcar_cmm_enable() first.77 *78 * TODO: Add support for LUT double buffer operations to avoid updating the79 * LUT table entries while a frame is being displayed.80 */81int rcar_cmm_setup(struct platform_device *pdev,82 const struct rcar_cmm_config *config)83{84 struct rcar_cmm *rcmm = platform_get_drvdata(pdev);85 86 /* Disable LUT if no table is provided. */87 if (!config->lut.table) {88 if (rcmm->lut.enabled) {89 rcar_cmm_write(rcmm, CM2_LUT_CTRL, 0);90 rcmm->lut.enabled = false;91 }92 93 return 0;94 }95 96 /* Enable LUT and program the new gamma table values. */97 if (!rcmm->lut.enabled) {98 rcar_cmm_write(rcmm, CM2_LUT_CTRL, CM2_LUT_CTRL_LUT_EN);99 rcmm->lut.enabled = true;100 }101 102 rcar_cmm_lut_write(rcmm, config->lut.table);103 104 return 0;105}106EXPORT_SYMBOL_GPL(rcar_cmm_setup);107 108/*109 * rcar_cmm_enable() - Enable the CMM unit110 * @pdev: The platform device associated with the CMM instance111 *112 * When the output of the corresponding DU channel is routed to the CMM unit,113 * the unit shall be enabled before the DU channel is started, and remain114 * enabled until the channel is stopped. The CMM unit shall be disabled with115 * rcar_cmm_disable().116 *117 * Calls to rcar_cmm_enable() and rcar_cmm_disable() are not reference-counted.118 * It is an error to attempt to enable an already enabled CMM unit, or to119 * attempt to disable a disabled unit.120 */121int rcar_cmm_enable(struct platform_device *pdev)122{123 int ret;124 125 ret = pm_runtime_resume_and_get(&pdev->dev);126 if (ret < 0)127 return ret;128 129 return 0;130}131EXPORT_SYMBOL_GPL(rcar_cmm_enable);132 133/*134 * rcar_cmm_disable() - Disable the CMM unit135 * @pdev: The platform device associated with the CMM instance136 *137 * See rcar_cmm_enable() for usage information.138 *139 * Disabling the CMM unit disable all the internal processing blocks. The CMM140 * state shall thus be restored with rcar_cmm_setup() when re-enabling the CMM141 * unit after the next rcar_cmm_enable() call.142 */143void rcar_cmm_disable(struct platform_device *pdev)144{145 struct rcar_cmm *rcmm = platform_get_drvdata(pdev);146 147 rcar_cmm_write(rcmm, CM2_LUT_CTRL, 0);148 rcmm->lut.enabled = false;149 150 pm_runtime_put(&pdev->dev);151}152EXPORT_SYMBOL_GPL(rcar_cmm_disable);153 154/*155 * rcar_cmm_init() - Initialize the CMM unit156 * @pdev: The platform device associated with the CMM instance157 *158 * Return: 0 on success, -EPROBE_DEFER if the CMM is not available yet,159 * -ENODEV if the DRM_RCAR_CMM config option is disabled160 */161int rcar_cmm_init(struct platform_device *pdev)162{163 struct rcar_cmm *rcmm = platform_get_drvdata(pdev);164 165 if (!rcmm)166 return -EPROBE_DEFER;167 168 return 0;169}170EXPORT_SYMBOL_GPL(rcar_cmm_init);171 172static int rcar_cmm_probe(struct platform_device *pdev)173{174 struct rcar_cmm *rcmm;175 176 rcmm = devm_kzalloc(&pdev->dev, sizeof(*rcmm), GFP_KERNEL);177 if (!rcmm)178 return -ENOMEM;179 platform_set_drvdata(pdev, rcmm);180 181 rcmm->base = devm_platform_ioremap_resource(pdev, 0);182 if (IS_ERR(rcmm->base))183 return PTR_ERR(rcmm->base);184 185 pm_runtime_enable(&pdev->dev);186 187 return 0;188}189 190static void rcar_cmm_remove(struct platform_device *pdev)191{192 pm_runtime_disable(&pdev->dev);193}194 195static const struct of_device_id rcar_cmm_of_table[] = {196 { .compatible = "renesas,rcar-gen3-cmm", },197 { .compatible = "renesas,rcar-gen2-cmm", },198 { },199};200MODULE_DEVICE_TABLE(of, rcar_cmm_of_table);201 202static struct platform_driver rcar_cmm_platform_driver = {203 .probe = rcar_cmm_probe,204 .remove_new = rcar_cmm_remove,205 .driver = {206 .name = "rcar-cmm",207 .of_match_table = rcar_cmm_of_table,208 },209};210 211module_platform_driver(rcar_cmm_platform_driver);212 213MODULE_AUTHOR("Jacopo Mondi <jacopo+renesas@jmondi.org>");214MODULE_DESCRIPTION("Renesas R-Car CMM Driver");215MODULE_LICENSE("GPL v2");216