drivers/mfd/mxs-lradc.c

   1 /*
   2  * Freescale MXS Low Resolution Analog-to-Digital Converter driver
   3  *
   4  * Copyright (c) 2012 DENX Software Engineering, GmbH.
   5  * Copyright (c) 2017 Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
   6  *
   7  * Authors:
   8  *  Marek Vasut <marex@denx.de>
   9  *  Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  19  * GNU General Public License for more details.
  20  */
  21
  22 #include <linux/clk.h>
  23 #include <linux/device.h>
  24 #include <linux/mfd/core.h>
  25 #include <linux/mfd/mxs-lradc.h>
  26 #include <linux/module.h>
  27 #include <linux/of.h>
  28 #include <linux/of_device.h>
  29 #include <linux/platform_device.h>
  30 #include <linux/slab.h>
  31
  32 #define ADC_CELL                0
  33 #define TSC_CELL                1
  34 #define RES_MEM                 0
  35
  36 enum mx23_lradc_irqs {
  37         MX23_LRADC_TS_IRQ = 0,
  38         MX23_LRADC_CH0_IRQ,
  39         MX23_LRADC_CH1_IRQ,
  40         MX23_LRADC_CH2_IRQ,
  41         MX23_LRADC_CH3_IRQ,
  42         MX23_LRADC_CH4_IRQ,
  43         MX23_LRADC_CH5_IRQ,
  44         MX23_LRADC_CH6_IRQ,
  45         MX23_LRADC_CH7_IRQ,
  46 };
  47
  48 enum mx28_lradc_irqs {
  49         MX28_LRADC_TS_IRQ = 0,
  50         MX28_LRADC_TRESH0_IRQ,
  51         MX28_LRADC_TRESH1_IRQ,
  52         MX28_LRADC_CH0_IRQ,
  53         MX28_LRADC_CH1_IRQ,
  54         MX28_LRADC_CH2_IRQ,
  55         MX28_LRADC_CH3_IRQ,
  56         MX28_LRADC_CH4_IRQ,
  57         MX28_LRADC_CH5_IRQ,
  58         MX28_LRADC_CH6_IRQ,
  59         MX28_LRADC_CH7_IRQ,
  60         MX28_LRADC_BUTTON0_IRQ,
  61         MX28_LRADC_BUTTON1_IRQ,
  62 };
  63
  64 static struct resource mx23_adc_resources[] = {
  65         DEFINE_RES_MEM(0x0, 0x0),
  66         DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH0_IRQ, "mxs-lradc-channel0"),
  67         DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH1_IRQ, "mxs-lradc-channel1"),
  68         DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH2_IRQ, "mxs-lradc-channel2"),
  69         DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH3_IRQ, "mxs-lradc-channel3"),
  70         DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH4_IRQ, "mxs-lradc-channel4"),
  71         DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH5_IRQ, "mxs-lradc-channel5"),
  72 };
  73
  74 static struct resource mx23_touchscreen_resources[] = {
  75         DEFINE_RES_MEM(0x0, 0x0),
  76         DEFINE_RES_IRQ_NAMED(MX23_LRADC_TS_IRQ, "mxs-lradc-touchscreen"),
  77         DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH6_IRQ, "mxs-lradc-channel6"),
  78         DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH7_IRQ, "mxs-lradc-channel7"),
  79 };
  80
  81 static struct resource mx28_adc_resources[] = {
  82         DEFINE_RES_MEM(0x0, 0x0),
  83         DEFINE_RES_IRQ_NAMED(MX28_LRADC_TRESH0_IRQ, "mxs-lradc-thresh0"),
  84         DEFINE_RES_IRQ_NAMED(MX28_LRADC_TRESH1_IRQ, "mxs-lradc-thresh1"),
  85         DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH0_IRQ, "mxs-lradc-channel0"),
  86         DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH1_IRQ, "mxs-lradc-channel1"),
  87         DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH2_IRQ, "mxs-lradc-channel2"),
  88         DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH3_IRQ, "mxs-lradc-channel3"),
  89         DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH4_IRQ, "mxs-lradc-channel4"),
  90         DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH5_IRQ, "mxs-lradc-channel5"),
  91         DEFINE_RES_IRQ_NAMED(MX28_LRADC_BUTTON0_IRQ, "mxs-lradc-button0"),
  92         DEFINE_RES_IRQ_NAMED(MX28_LRADC_BUTTON1_IRQ, "mxs-lradc-button1"),
  93 };
  94
  95 static struct resource mx28_touchscreen_resources[] = {
  96         DEFINE_RES_MEM(0x0, 0x0),
  97         DEFINE_RES_IRQ_NAMED(MX28_LRADC_TS_IRQ, "mxs-lradc-touchscreen"),
  98         DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH6_IRQ, "mxs-lradc-channel6"),
  99         DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH7_IRQ, "mxs-lradc-channel7"),
 100 };
 101
 102 static struct mfd_cell mx23_cells[] = {
 103         {
 104                 .name = "mxs-lradc-adc",
 105                 .resources = mx23_adc_resources,
 106                 .num_resources = ARRAY_SIZE(mx23_adc_resources),
 107         },
 108         {
 109                 .name = "mxs-lradc-ts",
 110                 .resources = mx23_touchscreen_resources,
 111                 .num_resources = ARRAY_SIZE(mx23_touchscreen_resources),
 112         },
 113 };
 114
 115 static struct mfd_cell mx28_cells[] = {
 116         {
 117                 .name = "mxs-lradc-adc",
 118                 .resources = mx28_adc_resources,
 119                 .num_resources = ARRAY_SIZE(mx28_adc_resources),
 120         },
 121         {
 122                 .name = "mxs-lradc-ts",
 123                 .resources = mx28_touchscreen_resources,
 124                 .num_resources = ARRAY_SIZE(mx28_touchscreen_resources),
 125         }
 126 };
 127
 128 static const struct of_device_id mxs_lradc_dt_ids[] = {
 129         { .compatible = "fsl,imx23-lradc", .data = (void *)IMX23_LRADC, },
 130         { .compatible = "fsl,imx28-lradc", .data = (void *)IMX28_LRADC, },
 131         { /* sentinel */ }
 132 };
 133 MODULE_DEVICE_TABLE(of, mxs_lradc_dt_ids);
 134
 135 static int mxs_lradc_probe(struct platform_device *pdev)
 136 {
 137         const struct of_device_id *of_id;
 138         struct device *dev = &pdev->dev;
 139         struct device_node *node = dev->of_node;
 140         struct mxs_lradc *lradc;
 141         struct mfd_cell *cells = NULL;
 142         struct resource *res;
 143         int ret = 0;
 144         u32 ts_wires = 0;
 145
 146         lradc = devm_kzalloc(&pdev->dev, sizeof(*lradc), GFP_KERNEL);
 147         if (!lradc)
 148                 return -ENOMEM;
 149
 150         of_id = of_match_device(mxs_lradc_dt_ids, &pdev->dev);
 151         if (!of_id)
 152                 return -EINVAL;
 153
 154         lradc->soc = (enum mxs_lradc_id)of_id->data;
 155
 156         lradc->clk = devm_clk_get(&pdev->dev, NULL);
 157         if (IS_ERR(lradc->clk)) {
 158                 dev_err(dev, "Failed to get the delay unit clock\n");
 159                 return PTR_ERR(lradc->clk);
 160         }
 161
 162         ret = clk_prepare_enable(lradc->clk);
 163         if (ret) {
 164                 dev_err(dev, "Failed to enable the delay unit clock\n");
 165                 return ret;
 166         }
 167
 168         ret = of_property_read_u32(node, "fsl,lradc-touchscreen-wires",
 169                                          &ts_wires);
 170
 171         if (!ret) {
 172                 lradc->buffer_vchans = BUFFER_VCHANS_LIMITED;
 173
 174                 switch (ts_wires) {
 175                 case 4:
 176                         lradc->touchscreen_wire = MXS_LRADC_TOUCHSCREEN_4WIRE;
 177                         break;
 178                 case 5:
 179                         if (lradc->soc == IMX28_LRADC) {
 180                                 lradc->touchscreen_wire =
 181                                         MXS_LRADC_TOUCHSCREEN_5WIRE;
 182                                 break;
 183                         }
 184                         /* fall through to an error message for i.MX23 */
 185                 default:
 186                         dev_err(&pdev->dev,
 187                                 "Unsupported number of touchscreen wires (%d)\n"
 188                                 , ts_wires);
 189                         ret = -EINVAL;
 190                         goto err_clk;
 191                 }
 192         } else {
 193                 lradc->buffer_vchans = BUFFER_VCHANS_ALL;
 194         }
 195
 196         platform_set_drvdata(pdev, lradc);
 197
 198         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 199         if (!res) {
 200                 ret = -ENOMEM;
 201                 goto err_clk;
 202         }
 203
 204         switch (lradc->soc) {
 205         case IMX23_LRADC:
 206                 mx23_adc_resources[RES_MEM] = *res;
 207                 mx23_touchscreen_resources[RES_MEM] = *res;
 208                 cells = mx23_cells;
 209                 break;
 210         case IMX28_LRADC:
 211                 mx28_adc_resources[RES_MEM] = *res;
 212                 mx28_touchscreen_resources[RES_MEM] = *res;
 213                 cells = mx28_cells;
 214                 break;
 215         default:
 216                 dev_err(dev, "Unsupported SoC\n");
 217                 ret = -ENODEV;
 218                 goto err_clk;
 219         }
 220
 221         ret = devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_NONE,
 222                                    &cells[ADC_CELL], 1, NULL, 0, NULL);
 223         if (ret) {
 224                 dev_err(&pdev->dev, "Failed to add the ADC subdevice\n");
 225                 goto err_clk;
 226         }
 227
 228         if (!lradc->touchscreen_wire)
 229                 return 0;
 230
 231         ret = devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_NONE,
 232                                    &cells[TSC_CELL], 1, NULL, 0, NULL);
 233         if (ret) {
 234                 dev_err(&pdev->dev,
 235                         "Failed to add the touchscreen subdevice\n");
 236                 goto err_clk;
 237         }
 238
 239         return 0;
 240
 241 err_clk:
 242         clk_disable_unprepare(lradc->clk);
 243
 244         return ret;
 245 }
 246
 247 static int mxs_lradc_remove(struct platform_device *pdev)
 248 {
 249         struct mxs_lradc *lradc = platform_get_drvdata(pdev);
 250
 251         clk_disable_unprepare(lradc->clk);
 252
 253         return 0;
 254 }
 255
 256 static struct platform_driver mxs_lradc_driver = {
 257         .driver = {
 258                 .name = "mxs-lradc",
 259                 .of_match_table = mxs_lradc_dt_ids,
 260         },
 261         .probe = mxs_lradc_probe,
 262         .remove = mxs_lradc_remove,
 263 };
 264 module_platform_driver(mxs_lradc_driver);
 265
 266 MODULE_AUTHOR("Ksenija Stanojevic <ksenija.stanojevic@gmail.com>");
 267 MODULE_DESCRIPTION("Freescale i.MX23/i.MX28 LRADC driver");
 268 MODULE_LICENSE("GPL");
 269 MODULE_ALIAS("platform:mxs-lradc");