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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (C) 2016 Imagination Technologies4 * Author: Paul Burton <paul.burton@mips.com>5 */6 7#include <linux/kernel.h>8#include <linux/io.h>9#include <linux/mfd/syscon.h>10#include <linux/module.h>11#include <linux/of.h>12#include <linux/platform_device.h>13#include <linux/property.h>14#include <linux/regmap.h>15#include <linux/slab.h>16 17#include "line-display.h"18 19struct img_ascii_lcd_ctx;20 21/**22 * struct img_ascii_lcd_config - Configuration information about an LCD model23 * @num_chars: the number of characters the LCD can display24 * @external_regmap: true if registers are in a system controller, else false25 * @ops: character line display operations26 */27struct img_ascii_lcd_config {28 unsigned int num_chars;29 bool external_regmap;30 const struct linedisp_ops ops;31};32 33/**34 * struct img_ascii_lcd_ctx - Private data structure35 * @linedisp: line display structure36 * @base: the base address of the LCD registers37 * @regmap: the regmap through which LCD registers are accessed38 * @offset: the offset within regmap to the start of the LCD registers39 * @cfg: pointer to the LCD model configuration40 */41struct img_ascii_lcd_ctx {42 struct linedisp linedisp;43 union {44 void __iomem *base;45 struct regmap *regmap;46 };47 u32 offset;48 const struct img_ascii_lcd_config *cfg;49};50 51/*52 * MIPS Boston development board53 */54 55static void boston_update(struct linedisp *linedisp)56{57 struct img_ascii_lcd_ctx *ctx =58 container_of(linedisp, struct img_ascii_lcd_ctx, linedisp);59 ulong val;60 61#if BITS_PER_LONG == 6462 val = *((u64 *)&linedisp->buf[0]);63 __raw_writeq(val, ctx->base);64#elif BITS_PER_LONG == 3265 val = *((u32 *)&linedisp->buf[0]);66 __raw_writel(val, ctx->base);67 val = *((u32 *)&linedisp->buf[4]);68 __raw_writel(val, ctx->base + 4);69#else70# error Not 32 or 64 bit71#endif72}73 74static struct img_ascii_lcd_config boston_config = {75 .num_chars = 8,76 .ops = {77 .update = boston_update,78 },79};80 81/*82 * MIPS Malta development board83 */84 85static void malta_update(struct linedisp *linedisp)86{87 struct img_ascii_lcd_ctx *ctx =88 container_of(linedisp, struct img_ascii_lcd_ctx, linedisp);89 unsigned int i;90 int err = 0;91 92 for (i = 0; i < linedisp->num_chars; i++) {93 err = regmap_write(ctx->regmap,94 ctx->offset + (i * 8), linedisp->buf[i]);95 if (err)96 break;97 }98 99 if (unlikely(err))100 pr_err_ratelimited("Failed to update LCD display: %d\n", err);101}102 103static struct img_ascii_lcd_config malta_config = {104 .num_chars = 8,105 .external_regmap = true,106 .ops = {107 .update = malta_update,108 },109};110 111/*112 * MIPS SEAD3 development board113 */114 115enum {116 SEAD3_REG_LCD_CTRL = 0x00,117#define SEAD3_REG_LCD_CTRL_SETDRAM BIT(7)118 SEAD3_REG_LCD_DATA = 0x08,119 SEAD3_REG_CPLD_STATUS = 0x10,120#define SEAD3_REG_CPLD_STATUS_BUSY BIT(0)121 SEAD3_REG_CPLD_DATA = 0x18,122#define SEAD3_REG_CPLD_DATA_BUSY BIT(7)123};124 125static int sead3_wait_sm_idle(struct img_ascii_lcd_ctx *ctx)126{127 unsigned int status;128 int err;129 130 do {131 err = regmap_read(ctx->regmap,132 ctx->offset + SEAD3_REG_CPLD_STATUS,133 &status);134 if (err)135 return err;136 } while (status & SEAD3_REG_CPLD_STATUS_BUSY);137 138 return 0;139 140}141 142static int sead3_wait_lcd_idle(struct img_ascii_lcd_ctx *ctx)143{144 unsigned int cpld_data;145 int err;146 147 err = sead3_wait_sm_idle(ctx);148 if (err)149 return err;150 151 do {152 err = regmap_read(ctx->regmap,153 ctx->offset + SEAD3_REG_LCD_CTRL,154 &cpld_data);155 if (err)156 return err;157 158 err = sead3_wait_sm_idle(ctx);159 if (err)160 return err;161 162 err = regmap_read(ctx->regmap,163 ctx->offset + SEAD3_REG_CPLD_DATA,164 &cpld_data);165 if (err)166 return err;167 } while (cpld_data & SEAD3_REG_CPLD_DATA_BUSY);168 169 return 0;170}171 172static void sead3_update(struct linedisp *linedisp)173{174 struct img_ascii_lcd_ctx *ctx =175 container_of(linedisp, struct img_ascii_lcd_ctx, linedisp);176 unsigned int i;177 int err = 0;178 179 for (i = 0; i < linedisp->num_chars; i++) {180 err = sead3_wait_lcd_idle(ctx);181 if (err)182 break;183 184 err = regmap_write(ctx->regmap,185 ctx->offset + SEAD3_REG_LCD_CTRL,186 SEAD3_REG_LCD_CTRL_SETDRAM | i);187 if (err)188 break;189 190 err = sead3_wait_lcd_idle(ctx);191 if (err)192 break;193 194 err = regmap_write(ctx->regmap,195 ctx->offset + SEAD3_REG_LCD_DATA,196 linedisp->buf[i]);197 if (err)198 break;199 }200 201 if (unlikely(err))202 pr_err_ratelimited("Failed to update LCD display: %d\n", err);203}204 205static struct img_ascii_lcd_config sead3_config = {206 .num_chars = 16,207 .external_regmap = true,208 .ops = {209 .update = sead3_update,210 },211};212 213static const struct of_device_id img_ascii_lcd_matches[] = {214 { .compatible = "img,boston-lcd", .data = &boston_config },215 { .compatible = "mti,malta-lcd", .data = &malta_config },216 { .compatible = "mti,sead3-lcd", .data = &sead3_config },217 { /* sentinel */ }218};219MODULE_DEVICE_TABLE(of, img_ascii_lcd_matches);220 221/**222 * img_ascii_lcd_probe() - probe an LCD display device223 * @pdev: the LCD platform device224 *225 * Probe an LCD display device, ensuring that we have the required resources in226 * order to access the LCD & setting up private data as well as sysfs files.227 *228 * Return: 0 on success, else -ERRNO229 */230static int img_ascii_lcd_probe(struct platform_device *pdev)231{232 struct device *dev = &pdev->dev;233 const struct img_ascii_lcd_config *cfg = device_get_match_data(dev);234 struct img_ascii_lcd_ctx *ctx;235 int err;236 237 ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);238 if (!ctx)239 return -ENOMEM;240 241 if (cfg->external_regmap) {242 ctx->regmap = syscon_node_to_regmap(dev->parent->of_node);243 if (IS_ERR(ctx->regmap))244 return PTR_ERR(ctx->regmap);245 246 if (of_property_read_u32(dev->of_node, "offset", &ctx->offset))247 return -EINVAL;248 } else {249 ctx->base = devm_platform_ioremap_resource(pdev, 0);250 if (IS_ERR(ctx->base))251 return PTR_ERR(ctx->base);252 }253 254 err = linedisp_register(&ctx->linedisp, dev, cfg->num_chars, &cfg->ops);255 if (err)256 return err;257 258 /* for backwards compatibility */259 err = compat_only_sysfs_link_entry_to_kobj(&dev->kobj,260 &ctx->linedisp.dev.kobj,261 "message", NULL);262 if (err)263 goto err_unregister;264 265 platform_set_drvdata(pdev, ctx);266 return 0;267 268err_unregister:269 linedisp_unregister(&ctx->linedisp);270 return err;271}272 273/**274 * img_ascii_lcd_remove() - remove an LCD display device275 * @pdev: the LCD platform device276 *277 * Remove an LCD display device, freeing private resources & ensuring that the278 * driver stops using the LCD display registers.279 */280static void img_ascii_lcd_remove(struct platform_device *pdev)281{282 struct img_ascii_lcd_ctx *ctx = platform_get_drvdata(pdev);283 284 sysfs_remove_link(&pdev->dev.kobj, "message");285 linedisp_unregister(&ctx->linedisp);286}287 288static struct platform_driver img_ascii_lcd_driver = {289 .driver = {290 .name = "img-ascii-lcd",291 .of_match_table = img_ascii_lcd_matches,292 },293 .probe = img_ascii_lcd_probe,294 .remove_new = img_ascii_lcd_remove,295};296module_platform_driver(img_ascii_lcd_driver);297 298MODULE_DESCRIPTION("Imagination Technologies ASCII LCD Display");299MODULE_AUTHOR("Paul Burton <paul.burton@mips.com>");300MODULE_LICENSE("GPL");301MODULE_IMPORT_NS(LINEDISP);302