drivers/mfd/atmel-hlcdc.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (C) 2014 Free Electrons
0004  * Copyright (C) 2014 Atmel
0005  *
0006  * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
0007  */
0008
0009 #include <linux/clk.h>
0010 #include <linux/iopoll.h>
0011 #include <linux/mfd/atmel-hlcdc.h>
0012 #include <linux/mfd/core.h>
0013 #include <linux/module.h>
0014 #include <linux/mod_devicetable.h>
0015 #include <linux/platform_device.h>
0016 #include <linux/regmap.h>
0017
0018 #define ATMEL_HLCDC_REG_MAX     (0x4000 - 0x4)
0019
0020 struct atmel_hlcdc_regmap {
0021     void __iomem *regs;
0022     struct device *dev;
0023 };
0024
0025 static const struct mfd_cell atmel_hlcdc_cells[] = {
0026     {
0027         .name = "atmel-hlcdc-pwm",
0028         .of_compatible = "atmel,hlcdc-pwm",
0029     },
0030     {
0031         .name = "atmel-hlcdc-dc",
0032         .of_compatible = "atmel,hlcdc-display-controller",
0033     },
0034 };
0035
0036 static int regmap_atmel_hlcdc_reg_write(void *context, unsigned int reg,
0037                     unsigned int val)
0038 {
0039     struct atmel_hlcdc_regmap *hregmap = context;
0040
0041     if (reg <= ATMEL_HLCDC_DIS) {
0042         u32 status;
0043         int ret;
0044
0045         ret = readl_poll_timeout_atomic(hregmap->regs + ATMEL_HLCDC_SR,
0046                         status,
0047                         !(status & ATMEL_HLCDC_SIP),
0048                         1, 100);
0049         if (ret) {
0050             dev_err(hregmap->dev,
0051                 "Timeout! Clock domain synchronization is in progress!\n");
0052             return ret;
0053         }
0054     }
0055
0056     writel(val, hregmap->regs + reg);
0057
0058     return 0;
0059 }
0060
0061 static int regmap_atmel_hlcdc_reg_read(void *context, unsigned int reg,
0062                        unsigned int *val)
0063 {
0064     struct atmel_hlcdc_regmap *hregmap = context;
0065
0066     *val = readl(hregmap->regs + reg);
0067
0068     return 0;
0069 }
0070
0071 static const struct regmap_config atmel_hlcdc_regmap_config = {
0072     .reg_bits = 32,
0073     .val_bits = 32,
0074     .reg_stride = 4,
0075     .max_register = ATMEL_HLCDC_REG_MAX,
0076     .reg_write = regmap_atmel_hlcdc_reg_write,
0077     .reg_read = regmap_atmel_hlcdc_reg_read,
0078     .fast_io = true,
0079 };
0080
0081 static int atmel_hlcdc_probe(struct platform_device *pdev)
0082 {
0083     struct atmel_hlcdc_regmap *hregmap;
0084     struct device *dev = &pdev->dev;
0085     struct atmel_hlcdc *hlcdc;
0086     struct resource *res;
0087
0088     hregmap = devm_kzalloc(dev, sizeof(*hregmap), GFP_KERNEL);
0089     if (!hregmap)
0090         return -ENOMEM;
0091
0092     hlcdc = devm_kzalloc(dev, sizeof(*hlcdc), GFP_KERNEL);
0093     if (!hlcdc)
0094         return -ENOMEM;
0095
0096     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
0097     hregmap->regs = devm_ioremap_resource(dev, res);
0098     if (IS_ERR(hregmap->regs))
0099         return PTR_ERR(hregmap->regs);
0100
0101     hregmap->dev = &pdev->dev;
0102
0103     hlcdc->irq = platform_get_irq(pdev, 0);
0104     if (hlcdc->irq < 0)
0105         return hlcdc->irq;
0106
0107     hlcdc->periph_clk = devm_clk_get(dev, "periph_clk");
0108     if (IS_ERR(hlcdc->periph_clk)) {
0109         dev_err(dev, "failed to get peripheral clock\n");
0110         return PTR_ERR(hlcdc->periph_clk);
0111     }
0112
0113     hlcdc->sys_clk = devm_clk_get(dev, "sys_clk");
0114     if (IS_ERR(hlcdc->sys_clk)) {
0115         dev_err(dev, "failed to get system clock\n");
0116         return PTR_ERR(hlcdc->sys_clk);
0117     }
0118
0119     hlcdc->slow_clk = devm_clk_get(dev, "slow_clk");
0120     if (IS_ERR(hlcdc->slow_clk)) {
0121         dev_err(dev, "failed to get slow clock\n");
0122         return PTR_ERR(hlcdc->slow_clk);
0123     }
0124
0125     hlcdc->regmap = devm_regmap_init(dev, NULL, hregmap,
0126                      &atmel_hlcdc_regmap_config);
0127     if (IS_ERR(hlcdc->regmap))
0128         return PTR_ERR(hlcdc->regmap);
0129
0130     dev_set_drvdata(dev, hlcdc);
0131
0132     return devm_mfd_add_devices(dev, -1, atmel_hlcdc_cells,
0133                     ARRAY_SIZE(atmel_hlcdc_cells),
0134                     NULL, 0, NULL);
0135 }
0136
0137 static const struct of_device_id atmel_hlcdc_match[] = {
0138     { .compatible = "atmel,at91sam9n12-hlcdc" },
0139     { .compatible = "atmel,at91sam9x5-hlcdc" },
0140     { .compatible = "atmel,sama5d2-hlcdc" },
0141     { .compatible = "atmel,sama5d3-hlcdc" },
0142     { .compatible = "atmel,sama5d4-hlcdc" },
0143     { .compatible = "microchip,sam9x60-hlcdc" },
0144     { /* sentinel */ },
0145 };
0146 MODULE_DEVICE_TABLE(of, atmel_hlcdc_match);
0147
0148 static struct platform_driver atmel_hlcdc_driver = {
0149     .probe = atmel_hlcdc_probe,
0150     .driver = {
0151         .name = "atmel-hlcdc",
0152         .of_match_table = atmel_hlcdc_match,
0153     },
0154 };
0155 module_platform_driver(atmel_hlcdc_driver);
0156
0157 MODULE_ALIAS("platform:atmel-hlcdc");
0158 MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
0159 MODULE_DESCRIPTION("Atmel HLCDC driver");
0160 MODULE_LICENSE("GPL v2");