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1// SPDX-License-Identifier: GPL-2.02//3// Copyright (c) 2015 Samsung Electronics Co., Ltd.4// http://www.samsung.com/5//6// Exynos - SROM Controller support7// Author: Pankaj Dubey <pankaj.dubey@samsung.com>8 9#include <linux/io.h>10#include <linux/init.h>11#include <linux/of.h>12#include <linux/of_address.h>13#include <linux/of_platform.h>14#include <linux/platform_device.h>15#include <linux/slab.h>16 17#include "exynos-srom.h"18 19static const unsigned long exynos_srom_offsets[] = {20 /* SROM side */21 EXYNOS_SROM_BW,22 EXYNOS_SROM_BC0,23 EXYNOS_SROM_BC1,24 EXYNOS_SROM_BC2,25 EXYNOS_SROM_BC3,26};27 28/**29 * struct exynos_srom_reg_dump: register dump of SROM Controller registers.30 * @offset: srom register offset from the controller base address.31 * @value: the value of register under the offset.32 */33struct exynos_srom_reg_dump {34 u32 offset;35 u32 value;36};37 38/**39 * struct exynos_srom: platform data for exynos srom controller driver.40 * @dev: platform device pointer41 * @reg_base: srom base address42 * @reg_offset: exynos_srom_reg_dump pointer to hold offset and its value.43 */44struct exynos_srom {45 struct device *dev;46 void __iomem *reg_base;47 struct exynos_srom_reg_dump *reg_offset;48};49 50static struct exynos_srom_reg_dump *51exynos_srom_alloc_reg_dump(const unsigned long *rdump,52 unsigned long nr_rdump)53{54 struct exynos_srom_reg_dump *rd;55 unsigned int i;56 57 rd = kcalloc(nr_rdump, sizeof(*rd), GFP_KERNEL);58 if (!rd)59 return NULL;60 61 for (i = 0; i < nr_rdump; ++i)62 rd[i].offset = rdump[i];63 64 return rd;65}66 67static int exynos_srom_configure_bank(struct exynos_srom *srom,68 struct device_node *np)69{70 u32 bank, width, pmc = 0;71 u32 timing[6];72 u32 cs, bw;73 74 if (of_property_read_u32(np, "reg", &bank))75 return -EINVAL;76 if (of_property_read_u32(np, "reg-io-width", &width))77 width = 1;78 if (of_property_read_bool(np, "samsung,srom-page-mode"))79 pmc = 1 << EXYNOS_SROM_BCX__PMC__SHIFT;80 if (of_property_read_u32_array(np, "samsung,srom-timing", timing,81 ARRAY_SIZE(timing)))82 return -EINVAL;83 84 bank *= 4; /* Convert bank into shift/offset */85 86 cs = 1 << EXYNOS_SROM_BW__BYTEENABLE__SHIFT;87 if (width == 2)88 cs |= 1 << EXYNOS_SROM_BW__DATAWIDTH__SHIFT;89 90 bw = readl_relaxed(srom->reg_base + EXYNOS_SROM_BW);91 bw = (bw & ~(EXYNOS_SROM_BW__CS_MASK << bank)) | (cs << bank);92 writel_relaxed(bw, srom->reg_base + EXYNOS_SROM_BW);93 94 writel_relaxed(pmc | (timing[0] << EXYNOS_SROM_BCX__TACP__SHIFT) |95 (timing[1] << EXYNOS_SROM_BCX__TCAH__SHIFT) |96 (timing[2] << EXYNOS_SROM_BCX__TCOH__SHIFT) |97 (timing[3] << EXYNOS_SROM_BCX__TACC__SHIFT) |98 (timing[4] << EXYNOS_SROM_BCX__TCOS__SHIFT) |99 (timing[5] << EXYNOS_SROM_BCX__TACS__SHIFT),100 srom->reg_base + EXYNOS_SROM_BC0 + bank);101 102 return 0;103}104 105static int exynos_srom_probe(struct platform_device *pdev)106{107 struct device_node *np, *child;108 struct exynos_srom *srom;109 struct device *dev = &pdev->dev;110 bool bad_bank_config = false;111 112 np = dev->of_node;113 if (!np) {114 dev_err(&pdev->dev, "could not find device info\n");115 return -EINVAL;116 }117 118 srom = devm_kzalloc(&pdev->dev,119 sizeof(struct exynos_srom), GFP_KERNEL);120 if (!srom)121 return -ENOMEM;122 123 srom->dev = dev;124 srom->reg_base = of_iomap(np, 0);125 if (!srom->reg_base) {126 dev_err(&pdev->dev, "iomap of exynos srom controller failed\n");127 return -ENOMEM;128 }129 130 platform_set_drvdata(pdev, srom);131 132 srom->reg_offset = exynos_srom_alloc_reg_dump(exynos_srom_offsets,133 ARRAY_SIZE(exynos_srom_offsets));134 if (!srom->reg_offset) {135 iounmap(srom->reg_base);136 return -ENOMEM;137 }138 139 for_each_child_of_node(np, child) {140 if (exynos_srom_configure_bank(srom, child)) {141 dev_err(dev,142 "Could not decode bank configuration for %pOFn\n",143 child);144 bad_bank_config = true;145 }146 }147 148 /*149 * If any bank failed to configure, we still provide suspend/resume,150 * but do not probe child devices151 */152 if (bad_bank_config)153 return 0;154 155 return of_platform_populate(np, NULL, NULL, dev);156}157 158#ifdef CONFIG_PM_SLEEP159static void exynos_srom_save(void __iomem *base,160 struct exynos_srom_reg_dump *rd,161 unsigned int num_regs)162{163 for (; num_regs > 0; --num_regs, ++rd)164 rd->value = readl(base + rd->offset);165}166 167static void exynos_srom_restore(void __iomem *base,168 const struct exynos_srom_reg_dump *rd,169 unsigned int num_regs)170{171 for (; num_regs > 0; --num_regs, ++rd)172 writel(rd->value, base + rd->offset);173}174 175static int exynos_srom_suspend(struct device *dev)176{177 struct exynos_srom *srom = dev_get_drvdata(dev);178 179 exynos_srom_save(srom->reg_base, srom->reg_offset,180 ARRAY_SIZE(exynos_srom_offsets));181 return 0;182}183 184static int exynos_srom_resume(struct device *dev)185{186 struct exynos_srom *srom = dev_get_drvdata(dev);187 188 exynos_srom_restore(srom->reg_base, srom->reg_offset,189 ARRAY_SIZE(exynos_srom_offsets));190 return 0;191}192#endif193 194static const struct of_device_id of_exynos_srom_ids[] = {195 {196 .compatible = "samsung,exynos4210-srom",197 },198 {},199};200 201static SIMPLE_DEV_PM_OPS(exynos_srom_pm_ops, exynos_srom_suspend, exynos_srom_resume);202 203static struct platform_driver exynos_srom_driver = {204 .probe = exynos_srom_probe,205 .driver = {206 .name = "exynos-srom",207 .of_match_table = of_exynos_srom_ids,208 .pm = &exynos_srom_pm_ops,209 .suppress_bind_attrs = true,210 },211};212builtin_platform_driver(exynos_srom_driver);213