drivers/mfd/jz4740-adc.c

   1 /*
   2  * Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
   3  * JZ4740 SoC ADC driver
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under  the terms of the GNU General  Public License as published by the
   7  * Free Software Foundation;  either version 2 of the License, or (at your
   8  * option) any later version.
   9  *
  10  * You should have received a copy of the GNU General Public License along
  11  * with this program; if not, write to the Free Software Foundation, Inc.,
  12  * 675 Mass Ave, Cambridge, MA 02139, USA.
  13  *
  14  * This driver synchronizes access to the JZ4740 ADC core between the
  15  * JZ4740 battery and hwmon drivers.
  16  */
  17
  18 #include <linux/err.h>
  19 #include <linux/irq.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/slab.h>
  25 #include <linux/spinlock.h>
  26
  27 #include <linux/clk.h>
  28 #include <linux/mfd/core.h>
  29
  30 #include <linux/jz4740-adc.h>
  31
  32
  33 #define JZ_REG_ADC_ENABLE       0x00
  34 #define JZ_REG_ADC_CFG          0x04
  35 #define JZ_REG_ADC_CTRL         0x08
  36 #define JZ_REG_ADC_STATUS       0x0c
  37
  38 #define JZ_REG_ADC_TOUCHSCREEN_BASE     0x10
  39 #define JZ_REG_ADC_BATTERY_BASE 0x1c
  40 #define JZ_REG_ADC_HWMON_BASE   0x20
  41
  42 #define JZ_ADC_ENABLE_TOUCH     BIT(2)
  43 #define JZ_ADC_ENABLE_BATTERY   BIT(1)
  44 #define JZ_ADC_ENABLE_ADCIN     BIT(0)
  45
  46 enum {
  47         JZ_ADC_IRQ_ADCIN = 0,
  48         JZ_ADC_IRQ_BATTERY,
  49         JZ_ADC_IRQ_TOUCH,
  50         JZ_ADC_IRQ_PENUP,
  51         JZ_ADC_IRQ_PENDOWN,
  52 };
  53
  54 struct jz4740_adc {
  55         struct resource *mem;
  56         void __iomem *base;
  57
  58         int irq;
  59         int irq_base;
  60
  61         struct clk *clk;
  62         atomic_t clk_ref;
  63
  64         spinlock_t lock;
  65 };
  66
  67 static inline void jz4740_adc_irq_set_masked(struct jz4740_adc *adc, int irq,
  68         bool masked)
  69 {
  70         unsigned long flags;
  71         uint8_t val;
  72
  73         irq -= adc->irq_base;
  74
  75         spin_lock_irqsave(&adc->lock, flags);
  76
  77         val = readb(adc->base + JZ_REG_ADC_CTRL);
  78         if (masked)
  79                 val |= BIT(irq);
  80         else
  81                 val &= ~BIT(irq);
  82         writeb(val, adc->base + JZ_REG_ADC_CTRL);
  83
  84         spin_unlock_irqrestore(&adc->lock, flags);
  85 }
  86
  87 static void jz4740_adc_irq_mask(unsigned int irq)
  88 {
  89         struct jz4740_adc *adc = get_irq_chip_data(irq);
  90         jz4740_adc_irq_set_masked(adc, irq, true);
  91 }
  92
  93 static void jz4740_adc_irq_unmask(unsigned int irq)
  94 {
  95         struct jz4740_adc *adc = get_irq_chip_data(irq);
  96         jz4740_adc_irq_set_masked(adc, irq, false);
  97 }
  98
  99 static void jz4740_adc_irq_ack(unsigned int irq)
 100 {
 101         struct jz4740_adc *adc = get_irq_chip_data(irq);
 102
 103         irq -= adc->irq_base;
 104         writeb(BIT(irq), adc->base + JZ_REG_ADC_STATUS);
 105 }
 106
 107 static struct irq_chip jz4740_adc_irq_chip = {
 108         .name = "jz4740-adc",
 109         .mask = jz4740_adc_irq_mask,
 110         .unmask = jz4740_adc_irq_unmask,
 111         .ack = jz4740_adc_irq_ack,
 112 };
 113
 114 static void jz4740_adc_irq_demux(unsigned int irq, struct irq_desc *desc)
 115 {
 116         struct jz4740_adc *adc = get_irq_desc_data(desc);
 117         uint8_t status;
 118         unsigned int i;
 119
 120         status = readb(adc->base + JZ_REG_ADC_STATUS);
 121
 122         for (i = 0; i < 5; ++i) {
 123                 if (status & BIT(i))
 124                         generic_handle_irq(adc->irq_base + i);
 125         }
 126 }
 127
 128
 129 /* Refcounting for the ADC clock is done in here instead of in the clock
 130  * framework, because it is the only clock which is shared between multiple
 131  * devices and thus is the only clock which needs refcounting */
 132 static inline void jz4740_adc_clk_enable(struct jz4740_adc *adc)
 133 {
 134         if (atomic_inc_return(&adc->clk_ref) == 1)
 135                 clk_enable(adc->clk);
 136 }
 137
 138 static inline void jz4740_adc_clk_disable(struct jz4740_adc *adc)
 139 {
 140         if (atomic_dec_return(&adc->clk_ref) == 0)
 141                 clk_disable(adc->clk);
 142 }
 143
 144 static inline void jz4740_adc_set_enabled(struct jz4740_adc *adc, int engine,
 145         bool enabled)
 146 {
 147         unsigned long flags;
 148         uint8_t val;
 149
 150         spin_lock_irqsave(&adc->lock, flags);
 151
 152         val = readb(adc->base + JZ_REG_ADC_ENABLE);
 153         if (enabled)
 154                 val |= BIT(engine);
 155         else
 156                 val &= ~BIT(engine);
 157         writeb(val, adc->base + JZ_REG_ADC_ENABLE);
 158
 159         spin_unlock_irqrestore(&adc->lock, flags);
 160 }
 161
 162 static int jz4740_adc_cell_enable(struct platform_device *pdev)
 163 {
 164         struct jz4740_adc *adc = dev_get_drvdata(pdev->dev.parent);
 165
 166         jz4740_adc_clk_enable(adc);
 167         jz4740_adc_set_enabled(adc, pdev->id, true);
 168
 169         return 0;
 170 }
 171
 172 static int jz4740_adc_cell_disable(struct platform_device *pdev)
 173 {
 174         struct jz4740_adc *adc = dev_get_drvdata(pdev->dev.parent);
 175
 176         jz4740_adc_set_enabled(adc, pdev->id, false);
 177         jz4740_adc_clk_disable(adc);
 178
 179         return 0;
 180 }
 181
 182 int jz4740_adc_set_config(struct device *dev, uint32_t mask, uint32_t val)
 183 {
 184         struct jz4740_adc *adc = dev_get_drvdata(dev);
 185         unsigned long flags;
 186         uint32_t cfg;
 187
 188         if (!adc)
 189                 return -ENODEV;
 190
 191         spin_lock_irqsave(&adc->lock, flags);
 192
 193         cfg = readl(adc->base + JZ_REG_ADC_CFG);
 194
 195         cfg &= ~mask;
 196         cfg |= val;
 197
 198         writel(cfg, adc->base + JZ_REG_ADC_CFG);
 199
 200         spin_unlock_irqrestore(&adc->lock, flags);
 201
 202         return 0;
 203 }
 204 EXPORT_SYMBOL_GPL(jz4740_adc_set_config);
 205
 206 static struct resource jz4740_hwmon_resources[] = {
 207         {
 208                 .start = JZ_ADC_IRQ_ADCIN,
 209                 .flags = IORESOURCE_IRQ,
 210         },
 211         {
 212                 .start  = JZ_REG_ADC_HWMON_BASE,
 213                 .end    = JZ_REG_ADC_HWMON_BASE + 3,
 214                 .flags  = IORESOURCE_MEM,
 215         },
 216 };
 217
 218 static struct resource jz4740_battery_resources[] = {
 219         {
 220                 .start = JZ_ADC_IRQ_BATTERY,
 221                 .flags = IORESOURCE_IRQ,
 222         },
 223         {
 224                 .start  = JZ_REG_ADC_BATTERY_BASE,
 225                 .end    = JZ_REG_ADC_BATTERY_BASE + 3,
 226                 .flags  = IORESOURCE_MEM,
 227         },
 228 };
 229
 230 const struct mfd_cell jz4740_adc_cells[] = {
 231         {
 232                 .id = 0,
 233                 .name = "jz4740-hwmon",
 234                 .num_resources = ARRAY_SIZE(jz4740_hwmon_resources),
 235                 .resources = jz4740_hwmon_resources,
 236                 .platform_data = (void *)&jz4740_adc_cells[0],
 237                 .data_size = sizeof(struct mfd_cell),
 238
 239                 .enable = jz4740_adc_cell_enable,
 240                 .disable = jz4740_adc_cell_disable,
 241         },
 242         {
 243                 .id = 1,
 244                 .name = "jz4740-battery",
 245                 .num_resources = ARRAY_SIZE(jz4740_battery_resources),
 246                 .resources = jz4740_battery_resources,
 247                 .platform_data = (void *)&jz4740_adc_cells[1],
 248                 .data_size = sizeof(struct mfd_cell),
 249
 250                 .enable = jz4740_adc_cell_enable,
 251                 .disable = jz4740_adc_cell_disable,
 252         },
 253 };
 254
 255 static int __devinit jz4740_adc_probe(struct platform_device *pdev)
 256 {
 257         int ret;
 258         struct jz4740_adc *adc;
 259         struct resource *mem_base;
 260         int irq;
 261
 262         adc = kmalloc(sizeof(*adc), GFP_KERNEL);
 263         if (!adc) {
 264                 dev_err(&pdev->dev, "Failed to allocate driver structure\n");
 265                 return -ENOMEM;
 266         }
 267
 268         adc->irq = platform_get_irq(pdev, 0);
 269         if (adc->irq < 0) {
 270                 ret = adc->irq;
 271                 dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
 272                 goto err_free;
 273         }
 274
 275         adc->irq_base = platform_get_irq(pdev, 1);
 276         if (adc->irq_base < 0) {
 277                 ret = adc->irq_base;
 278                 dev_err(&pdev->dev, "Failed to get irq base: %d\n", ret);
 279                 goto err_free;
 280         }
 281
 282         mem_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 283         if (!mem_base) {
 284                 ret = -ENOENT;
 285                 dev_err(&pdev->dev, "Failed to get platform mmio resource\n");
 286                 goto err_free;
 287         }
 288
 289         /* Only request the shared registers for the MFD driver */
 290         adc->mem = request_mem_region(mem_base->start, JZ_REG_ADC_STATUS,
 291                                         pdev->name);
 292         if (!adc->mem) {
 293                 ret = -EBUSY;
 294                 dev_err(&pdev->dev, "Failed to request mmio memory region\n");
 295                 goto err_free;
 296         }
 297
 298         adc->base = ioremap_nocache(adc->mem->start, resource_size(adc->mem));
 299         if (!adc->base) {
 300                 ret = -EBUSY;
 301                 dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
 302                 goto err_release_mem_region;
 303         }
 304
 305         adc->clk = clk_get(&pdev->dev, "adc");
 306         if (IS_ERR(adc->clk)) {
 307                 ret = PTR_ERR(adc->clk);
 308                 dev_err(&pdev->dev, "Failed to get clock: %d\n", ret);
 309                 goto err_iounmap;
 310         }
 311
 312         spin_lock_init(&adc->lock);
 313         atomic_set(&adc->clk_ref, 0);
 314
 315         platform_set_drvdata(pdev, adc);
 316
 317         for (irq = adc->irq_base; irq < adc->irq_base + 5; ++irq) {
 318                 set_irq_chip_data(irq, adc);
 319                 set_irq_chip_and_handler(irq, &jz4740_adc_irq_chip,
 320                     handle_level_irq);
 321         }
 322
 323         set_irq_data(adc->irq, adc);
 324         set_irq_chained_handler(adc->irq, jz4740_adc_irq_demux);
 325
 326         writeb(0x00, adc->base + JZ_REG_ADC_ENABLE);
 327         writeb(0xff, adc->base + JZ_REG_ADC_CTRL);
 328
 329         ret = mfd_add_devices(&pdev->dev, 0, jz4740_adc_cells,
 330                 ARRAY_SIZE(jz4740_adc_cells), mem_base, adc->irq_base);
 331         if (ret < 0)
 332                 goto err_clk_put;
 333
 334         return 0;
 335
 336 err_clk_put:
 337         clk_put(adc->clk);
 338 err_iounmap:
 339         platform_set_drvdata(pdev, NULL);
 340         iounmap(adc->base);
 341 err_release_mem_region:
 342         release_mem_region(adc->mem->start, resource_size(adc->mem));
 343 err_free:
 344         kfree(adc);
 345
 346         return ret;
 347 }
 348
 349 static int __devexit jz4740_adc_remove(struct platform_device *pdev)
 350 {
 351         struct jz4740_adc *adc = platform_get_drvdata(pdev);
 352
 353         mfd_remove_devices(&pdev->dev);
 354
 355         set_irq_data(adc->irq, NULL);
 356         set_irq_chained_handler(adc->irq, NULL);
 357
 358         iounmap(adc->base);
 359         release_mem_region(adc->mem->start, resource_size(adc->mem));
 360
 361         clk_put(adc->clk);
 362
 363         platform_set_drvdata(pdev, NULL);
 364
 365         kfree(adc);
 366
 367         return 0;
 368 }
 369
 370 struct platform_driver jz4740_adc_driver = {
 371         .probe  = jz4740_adc_probe,
 372         .remove = __devexit_p(jz4740_adc_remove),
 373         .driver = {
 374                 .name = "jz4740-adc",
 375                 .owner = THIS_MODULE,
 376         },
 377 };
 378
 379 static int __init jz4740_adc_init(void)
 380 {
 381         return platform_driver_register(&jz4740_adc_driver);
 382 }
 383 module_init(jz4740_adc_init);
 384
 385 static void __exit jz4740_adc_exit(void)
 386 {
 387         platform_driver_unregister(&jz4740_adc_driver);
 388 }
 389 module_exit(jz4740_adc_exit);
 390
 391 MODULE_DESCRIPTION("JZ4740 SoC ADC driver");
 392 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 393 MODULE_LICENSE("GPL");
 394 MODULE_ALIAS("platform:jz4740-adc");