1 /* 2 * TI Touch Screen / ADC MFD driver 3 * 4 * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/ 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as 8 * published by the Free Software Foundation version 2. 9 * 10 * This program is distributed "as is" WITHOUT ANY WARRANTY of any 11 * kind, whether express or implied; without even the implied warranty 12 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 */ 15 16 #include <linux/module.h> 17 #include <linux/init.h> 18 #include <linux/slab.h> 19 #include <linux/err.h> 20 #include <linux/io.h> 21 #include <linux/clk.h> 22 #include <linux/regmap.h> 23 #include <linux/mfd/core.h> 24 #include <linux/pm_runtime.h> 25 #include <linux/of.h> 26 #include <linux/of_device.h> 27 28 #include <linux/mfd/ti_am335x_tscadc.h> 29 30 static unsigned int tscadc_readl(struct ti_tscadc_dev *tsadc, unsigned int reg) 31 { 32 unsigned int val; 33 34 regmap_read(tsadc->regmap_tscadc, reg, &val); 35 return val; 36 } 37 38 static void tscadc_writel(struct ti_tscadc_dev *tsadc, unsigned int reg, 39 unsigned int val) 40 { 41 regmap_write(tsadc->regmap_tscadc, reg, val); 42 } 43 44 static const struct regmap_config tscadc_regmap_config = { 45 .name = "ti_tscadc", 46 .reg_bits = 32, 47 .reg_stride = 4, 48 .val_bits = 32, 49 }; 50 51 void am335x_tsc_se_update(struct ti_tscadc_dev *tsadc) 52 { 53 tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache); 54 } 55 EXPORT_SYMBOL_GPL(am335x_tsc_se_update); 56 57 void am335x_tsc_se_set(struct ti_tscadc_dev *tsadc, u32 val) 58 { 59 spin_lock(&tsadc->reg_lock); 60 tsadc->reg_se_cache |= val; 61 spin_unlock(&tsadc->reg_lock); 62 63 am335x_tsc_se_update(tsadc); 64 } 65 EXPORT_SYMBOL_GPL(am335x_tsc_se_set); 66 67 void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val) 68 { 69 spin_lock(&tsadc->reg_lock); 70 tsadc->reg_se_cache &= ~val; 71 spin_unlock(&tsadc->reg_lock); 72 73 am335x_tsc_se_update(tsadc); 74 } 75 EXPORT_SYMBOL_GPL(am335x_tsc_se_clr); 76 77 static void tscadc_idle_config(struct ti_tscadc_dev *config) 78 { 79 unsigned int idleconfig; 80 81 idleconfig = STEPCONFIG_YNN | STEPCONFIG_INM_ADCREFM | 82 STEPCONFIG_INP_ADCREFM | STEPCONFIG_YPN; 83 84 tscadc_writel(config, REG_IDLECONFIG, idleconfig); 85 } 86 87 static int ti_tscadc_probe(struct platform_device *pdev) 88 { 89 struct ti_tscadc_dev *tscadc; 90 struct resource *res; 91 struct clk *clk; 92 struct device_node *node = pdev->dev.of_node; 93 struct mfd_cell *cell; 94 struct property *prop; 95 const __be32 *cur; 96 u32 val; 97 int err, ctrl; 98 int clk_value, clock_rate; 99 int tsc_wires = 0, adc_channels = 0, total_channels; 100 int readouts = 0; 101 102 if (!pdev->dev.of_node) { 103 dev_err(&pdev->dev, "Could not find valid DT data.\n"); 104 return -EINVAL; 105 } 106 107 node = of_get_child_by_name(pdev->dev.of_node, "tsc"); 108 of_property_read_u32(node, "ti,wires", &tsc_wires); 109 of_property_read_u32(node, "ti,coordiante-readouts", &readouts); 110 111 node = of_get_child_by_name(pdev->dev.of_node, "adc"); 112 of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) { 113 adc_channels++; 114 if (val > 7) { 115 dev_err(&pdev->dev, " PIN numbers are 0..7 (not %d)\n", 116 val); 117 return -EINVAL; 118 } 119 } 120 total_channels = tsc_wires + adc_channels; 121 if (total_channels > 8) { 122 dev_err(&pdev->dev, "Number of i/p channels more than 8\n"); 123 return -EINVAL; 124 } 125 if (total_channels == 0) { 126 dev_err(&pdev->dev, "Need atleast one channel.\n"); 127 return -EINVAL; 128 } 129 130 if (readouts * 2 + 2 + adc_channels > 16) { 131 dev_err(&pdev->dev, "Too many step configurations requested\n"); 132 return -EINVAL; 133 } 134 135 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 136 if (!res) { 137 dev_err(&pdev->dev, "no memory resource defined.\n"); 138 return -EINVAL; 139 } 140 141 /* Allocate memory for device */ 142 tscadc = devm_kzalloc(&pdev->dev, 143 sizeof(struct ti_tscadc_dev), GFP_KERNEL); 144 if (!tscadc) { 145 dev_err(&pdev->dev, "failed to allocate memory.\n"); 146 return -ENOMEM; 147 } 148 tscadc->dev = &pdev->dev; 149 150 err = platform_get_irq(pdev, 0); 151 if (err < 0) { 152 dev_err(&pdev->dev, "no irq ID is specified.\n"); 153 goto ret; 154 } else 155 tscadc->irq = err; 156 157 res = devm_request_mem_region(&pdev->dev, 158 res->start, resource_size(res), pdev->name); 159 if (!res) { 160 dev_err(&pdev->dev, "failed to reserve registers.\n"); 161 return -EBUSY; 162 } 163 164 tscadc->tscadc_base = devm_ioremap(&pdev->dev, 165 res->start, resource_size(res)); 166 if (!tscadc->tscadc_base) { 167 dev_err(&pdev->dev, "failed to map registers.\n"); 168 return -ENOMEM; 169 } 170 171 tscadc->regmap_tscadc = devm_regmap_init_mmio(&pdev->dev, 172 tscadc->tscadc_base, &tscadc_regmap_config); 173 if (IS_ERR(tscadc->regmap_tscadc)) { 174 dev_err(&pdev->dev, "regmap init failed\n"); 175 err = PTR_ERR(tscadc->regmap_tscadc); 176 goto ret; 177 } 178 179 spin_lock_init(&tscadc->reg_lock); 180 pm_runtime_enable(&pdev->dev); 181 pm_runtime_get_sync(&pdev->dev); 182 183 /* 184 * The TSC_ADC_Subsystem has 2 clock domains 185 * OCP_CLK and ADC_CLK. 186 * The ADC clock is expected to run at target of 3MHz, 187 * and expected to capture 12-bit data at a rate of 200 KSPS. 188 * The TSC_ADC_SS controller design assumes the OCP clock is 189 * at least 6x faster than the ADC clock. 190 */ 191 clk = clk_get(&pdev->dev, "adc_tsc_fck"); 192 if (IS_ERR(clk)) { 193 dev_err(&pdev->dev, "failed to get TSC fck\n"); 194 err = PTR_ERR(clk); 195 goto err_disable_clk; 196 } 197 clock_rate = clk_get_rate(clk); 198 clk_put(clk); 199 clk_value = clock_rate / ADC_CLK; 200 if (clk_value < MAX_CLK_DIV) { 201 dev_err(&pdev->dev, "clock input less than min clock requirement\n"); 202 err = -EINVAL; 203 goto err_disable_clk; 204 } 205 /* TSCADC_CLKDIV needs to be configured to the value minus 1 */ 206 clk_value = clk_value - 1; 207 tscadc_writel(tscadc, REG_CLKDIV, clk_value); 208 209 /* Set the control register bits */ 210 ctrl = CNTRLREG_STEPCONFIGWRT | 211 CNTRLREG_TSCENB | 212 CNTRLREG_STEPID | 213 CNTRLREG_4WIRE; 214 tscadc_writel(tscadc, REG_CTRL, ctrl); 215 216 /* Set register bits for Idle Config Mode */ 217 tscadc_idle_config(tscadc); 218 219 /* Enable the TSC module enable bit */ 220 ctrl = tscadc_readl(tscadc, REG_CTRL); 221 ctrl |= CNTRLREG_TSCSSENB; 222 tscadc_writel(tscadc, REG_CTRL, ctrl); 223 224 tscadc->used_cells = 0; 225 tscadc->tsc_cell = -1; 226 tscadc->adc_cell = -1; 227 228 /* TSC Cell */ 229 if (tsc_wires > 0) { 230 tscadc->tsc_cell = tscadc->used_cells; 231 cell = &tscadc->cells[tscadc->used_cells++]; 232 cell->name = "TI-am335x-tsc"; 233 cell->of_compatible = "ti,am3359-tsc"; 234 cell->platform_data = &tscadc; 235 cell->pdata_size = sizeof(tscadc); 236 } 237 238 /* ADC Cell */ 239 if (adc_channels > 0) { 240 tscadc->adc_cell = tscadc->used_cells; 241 cell = &tscadc->cells[tscadc->used_cells++]; 242 cell->name = "TI-am335x-adc"; 243 cell->of_compatible = "ti,am3359-adc"; 244 cell->platform_data = &tscadc; 245 cell->pdata_size = sizeof(tscadc); 246 } 247 248 err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells, 249 tscadc->used_cells, NULL, 0, NULL); 250 if (err < 0) 251 goto err_disable_clk; 252 253 device_init_wakeup(&pdev->dev, true); 254 platform_set_drvdata(pdev, tscadc); 255 return 0; 256 257 err_disable_clk: 258 pm_runtime_put_sync(&pdev->dev); 259 pm_runtime_disable(&pdev->dev); 260 ret: 261 return err; 262 } 263 264 static int ti_tscadc_remove(struct platform_device *pdev) 265 { 266 struct ti_tscadc_dev *tscadc = platform_get_drvdata(pdev); 267 268 tscadc_writel(tscadc, REG_SE, 0x00); 269 270 pm_runtime_put_sync(&pdev->dev); 271 pm_runtime_disable(&pdev->dev); 272 273 mfd_remove_devices(tscadc->dev); 274 275 return 0; 276 } 277 278 #ifdef CONFIG_PM 279 static int tscadc_suspend(struct device *dev) 280 { 281 struct ti_tscadc_dev *tscadc_dev = dev_get_drvdata(dev); 282 283 tscadc_writel(tscadc_dev, REG_SE, 0x00); 284 pm_runtime_put_sync(dev); 285 286 return 0; 287 } 288 289 static int tscadc_resume(struct device *dev) 290 { 291 struct ti_tscadc_dev *tscadc_dev = dev_get_drvdata(dev); 292 unsigned int restore, ctrl; 293 294 pm_runtime_get_sync(dev); 295 296 /* context restore */ 297 ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_TSCENB | 298 CNTRLREG_STEPID | CNTRLREG_4WIRE; 299 tscadc_writel(tscadc_dev, REG_CTRL, ctrl); 300 tscadc_idle_config(tscadc_dev); 301 am335x_tsc_se_update(tscadc_dev); 302 restore = tscadc_readl(tscadc_dev, REG_CTRL); 303 tscadc_writel(tscadc_dev, REG_CTRL, 304 (restore | CNTRLREG_TSCSSENB)); 305 306 return 0; 307 } 308 309 static const struct dev_pm_ops tscadc_pm_ops = { 310 .suspend = tscadc_suspend, 311 .resume = tscadc_resume, 312 }; 313 #define TSCADC_PM_OPS (&tscadc_pm_ops) 314 #else 315 #define TSCADC_PM_OPS NULL 316 #endif 317 318 static const struct of_device_id ti_tscadc_dt_ids[] = { 319 { .compatible = "ti,am3359-tscadc", }, 320 { } 321 }; 322 MODULE_DEVICE_TABLE(of, ti_tscadc_dt_ids); 323 324 static struct platform_driver ti_tscadc_driver = { 325 .driver = { 326 .name = "ti_am3359-tscadc", 327 .owner = THIS_MODULE, 328 .pm = TSCADC_PM_OPS, 329 .of_match_table = of_match_ptr(ti_tscadc_dt_ids), 330 }, 331 .probe = ti_tscadc_probe, 332 .remove = ti_tscadc_remove, 333 334 }; 335 336 module_platform_driver(ti_tscadc_driver); 337 338 MODULE_DESCRIPTION("TI touchscreen / ADC MFD controller driver"); 339 MODULE_AUTHOR("Rachna Patil <rachna@ti.com>"); 340 MODULE_LICENSE("GPL"); 341