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         struct irq_chip_generic *gc;
  60
  61         struct clk *clk;
  62         atomic_t clk_ref;
  63
  64         spinlock_t lock;
  65 };
  66
  67 static void jz4740_adc_irq_demux(unsigned int irq, struct irq_desc *desc)
  68 {
  69         struct irq_chip_generic *gc = irq_desc_get_handler_data(desc);
  70         uint8_t status;
  71         unsigned int i;
  72
  73         status = readb(gc->reg_base + JZ_REG_ADC_STATUS);
  74
  75         for (i = 0; i < 5; ++i) {
  76                 if (status & BIT(i))
  77                         generic_handle_irq(gc->irq_base + i);
  78         }
  79 }
  80
  81
  82 /* Refcounting for the ADC clock is done in here instead of in the clock
  83  * framework, because it is the only clock which is shared between multiple
  84  * devices and thus is the only clock which needs refcounting */
  85 static inline void jz4740_adc_clk_enable(struct jz4740_adc *adc)
  86 {
  87         if (atomic_inc_return(&adc->clk_ref) == 1)
  88                 clk_enable(adc->clk);
  89 }
  90
  91 static inline void jz4740_adc_clk_disable(struct jz4740_adc *adc)
  92 {
  93         if (atomic_dec_return(&adc->clk_ref) == 0)
  94                 clk_disable(adc->clk);
  95 }
  96
  97 static inline void jz4740_adc_set_enabled(struct jz4740_adc *adc, int engine,
  98         bool enabled)
  99 {
 100         unsigned long flags;
 101         uint8_t val;
 102
 103         spin_lock_irqsave(&adc->lock, flags);
 104
 105         val = readb(adc->base + JZ_REG_ADC_ENABLE);
 106         if (enabled)
 107                 val |= BIT(engine);
 108         else
 109                 val &= ~BIT(engine);
 110         writeb(val, adc->base + JZ_REG_ADC_ENABLE);
 111
 112         spin_unlock_irqrestore(&adc->lock, flags);
 113 }
 114
 115 static int jz4740_adc_cell_enable(struct platform_device *pdev)
 116 {
 117         struct jz4740_adc *adc = dev_get_drvdata(pdev->dev.parent);
 118
 119         jz4740_adc_clk_enable(adc);
 120         jz4740_adc_set_enabled(adc, pdev->id, true);
 121
 122         return 0;
 123 }
 124
 125 static int jz4740_adc_cell_disable(struct platform_device *pdev)
 126 {
 127         struct jz4740_adc *adc = dev_get_drvdata(pdev->dev.parent);
 128
 129         jz4740_adc_set_enabled(adc, pdev->id, false);
 130         jz4740_adc_clk_disable(adc);
 131
 132         return 0;
 133 }
 134
 135 int jz4740_adc_set_config(struct device *dev, uint32_t mask, uint32_t val)
 136 {
 137         struct jz4740_adc *adc = dev_get_drvdata(dev);
 138         unsigned long flags;
 139         uint32_t cfg;
 140
 141         if (!adc)
 142                 return -ENODEV;
 143
 144         spin_lock_irqsave(&adc->lock, flags);
 145
 146         cfg = readl(adc->base + JZ_REG_ADC_CFG);
 147
 148         cfg &= ~mask;
 149         cfg |= val;
 150
 151         writel(cfg, adc->base + JZ_REG_ADC_CFG);
 152
 153         spin_unlock_irqrestore(&adc->lock, flags);
 154
 155         return 0;
 156 }
 157 EXPORT_SYMBOL_GPL(jz4740_adc_set_config);
 158
 159 static struct resource jz4740_hwmon_resources[] = {
 160         {
 161                 .start = JZ_ADC_IRQ_ADCIN,
 162                 .flags = IORESOURCE_IRQ,
 163         },
 164         {
 165                 .start  = JZ_REG_ADC_HWMON_BASE,
 166                 .end    = JZ_REG_ADC_HWMON_BASE + 3,
 167                 .flags  = IORESOURCE_MEM,
 168         },
 169 };
 170
 171 static struct resource jz4740_battery_resources[] = {
 172         {
 173                 .start = JZ_ADC_IRQ_BATTERY,
 174                 .flags = IORESOURCE_IRQ,
 175         },
 176         {
 177                 .start  = JZ_REG_ADC_BATTERY_BASE,
 178                 .end    = JZ_REG_ADC_BATTERY_BASE + 3,
 179                 .flags  = IORESOURCE_MEM,
 180         },
 181 };
 182
 183 const struct mfd_cell jz4740_adc_cells[] = {
 184         {
 185                 .id = 0,
 186                 .name = "jz4740-hwmon",
 187                 .num_resources = ARRAY_SIZE(jz4740_hwmon_resources),
 188                 .resources = jz4740_hwmon_resources,
 189
 190                 .enable = jz4740_adc_cell_enable,
 191                 .disable = jz4740_adc_cell_disable,
 192         },
 193         {
 194                 .id = 1,
 195                 .name = "jz4740-battery",
 196                 .num_resources = ARRAY_SIZE(jz4740_battery_resources),
 197                 .resources = jz4740_battery_resources,
 198
 199                 .enable = jz4740_adc_cell_enable,
 200                 .disable = jz4740_adc_cell_disable,
 201         },
 202 };
 203
 204 static int __devinit jz4740_adc_probe(struct platform_device *pdev)
 205 {
 206         struct irq_chip_generic *gc;
 207         struct irq_chip_type *ct;
 208         struct jz4740_adc *adc;
 209         struct resource *mem_base;
 210         int ret;
 211         int irq_base;
 212
 213         adc = kmalloc(sizeof(*adc), GFP_KERNEL);
 214         if (!adc) {
 215                 dev_err(&pdev->dev, "Failed to allocate driver structure\n");
 216                 return -ENOMEM;
 217         }
 218
 219         adc->irq = platform_get_irq(pdev, 0);
 220         if (adc->irq < 0) {
 221                 ret = adc->irq;
 222                 dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
 223                 goto err_free;
 224         }
 225
 226         irq_base = platform_get_irq(pdev, 1);
 227         if (irq_base < 0) {
 228                 ret = irq_base;
 229                 dev_err(&pdev->dev, "Failed to get irq base: %d\n", ret);
 230                 goto err_free;
 231         }
 232
 233         mem_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 234         if (!mem_base) {
 235                 ret = -ENOENT;
 236                 dev_err(&pdev->dev, "Failed to get platform mmio resource\n");
 237                 goto err_free;
 238         }
 239
 240         /* Only request the shared registers for the MFD driver */
 241         adc->mem = request_mem_region(mem_base->start, JZ_REG_ADC_STATUS,
 242                                         pdev->name);
 243         if (!adc->mem) {
 244                 ret = -EBUSY;
 245                 dev_err(&pdev->dev, "Failed to request mmio memory region\n");
 246                 goto err_free;
 247         }
 248
 249         adc->base = ioremap_nocache(adc->mem->start, resource_size(adc->mem));
 250         if (!adc->base) {
 251                 ret = -EBUSY;
 252                 dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
 253                 goto err_release_mem_region;
 254         }
 255
 256         adc->clk = clk_get(&pdev->dev, "adc");
 257         if (IS_ERR(adc->clk)) {
 258                 ret = PTR_ERR(adc->clk);
 259                 dev_err(&pdev->dev, "Failed to get clock: %d\n", ret);
 260                 goto err_iounmap;
 261         }
 262
 263         spin_lock_init(&adc->lock);
 264         atomic_set(&adc->clk_ref, 0);
 265
 266         platform_set_drvdata(pdev, adc);
 267
 268         gc = irq_alloc_generic_chip("INTC", 1, irq_base, adc->base,
 269                 handle_level_irq);
 270
 271         ct = gc->chip_types;
 272         ct->regs.mask = JZ_REG_ADC_CTRL;
 273         ct->regs.ack = JZ_REG_ADC_STATUS;
 274         ct->chip.irq_mask = irq_gc_mask_set_bit;
 275         ct->chip.irq_unmask = irq_gc_mask_clr_bit;
 276         ct->chip.irq_ack = irq_gc_ack;
 277
 278         irq_setup_generic_chip(gc, IRQ_MSK(5), 0, 0, IRQ_NOPROBE | IRQ_LEVEL);
 279
 280         adc->gc = gc;
 281
 282         irq_set_handler_data(adc->irq, gc);
 283         irq_set_chained_handler(adc->irq, jz4740_adc_irq_demux);
 284
 285         writeb(0x00, adc->base + JZ_REG_ADC_ENABLE);
 286         writeb(0xff, adc->base + JZ_REG_ADC_CTRL);
 287
 288         ret = mfd_add_devices(&pdev->dev, 0, jz4740_adc_cells,
 289                 ARRAY_SIZE(jz4740_adc_cells), mem_base, irq_base);
 290         if (ret < 0)
 291                 goto err_clk_put;
 292
 293         return 0;
 294
 295 err_clk_put:
 296         clk_put(adc->clk);
 297 err_iounmap:
 298         platform_set_drvdata(pdev, NULL);
 299         iounmap(adc->base);
 300 err_release_mem_region:
 301         release_mem_region(adc->mem->start, resource_size(adc->mem));
 302 err_free:
 303         kfree(adc);
 304
 305         return ret;
 306 }
 307
 308 static int __devexit jz4740_adc_remove(struct platform_device *pdev)
 309 {
 310         struct jz4740_adc *adc = platform_get_drvdata(pdev);
 311
 312         mfd_remove_devices(&pdev->dev);
 313
 314         irq_remove_generic_chip(adc->gc, IRQ_MSK(5), IRQ_NOPROBE | IRQ_LEVEL, 0);
 315         kfree(adc->gc);
 316         irq_set_handler_data(adc->irq, NULL);
 317         irq_set_chained_handler(adc->irq, NULL);
 318
 319         iounmap(adc->base);
 320         release_mem_region(adc->mem->start, resource_size(adc->mem));
 321
 322         clk_put(adc->clk);
 323
 324         platform_set_drvdata(pdev, NULL);
 325
 326         kfree(adc);
 327
 328         return 0;
 329 }
 330
 331 struct platform_driver jz4740_adc_driver = {
 332         .probe  = jz4740_adc_probe,
 333         .remove = __devexit_p(jz4740_adc_remove),
 334         .driver = {
 335                 .name = "jz4740-adc",
 336                 .owner = THIS_MODULE,
 337         },
 338 };
 339
 340 static int __init jz4740_adc_init(void)
 341 {
 342         return platform_driver_register(&jz4740_adc_driver);
 343 }
 344 module_init(jz4740_adc_init);
 345
 346 static void __exit jz4740_adc_exit(void)
 347 {
 348         platform_driver_unregister(&jz4740_adc_driver);
 349 }
 350 module_exit(jz4740_adc_exit);
 351
 352 MODULE_DESCRIPTION("JZ4740 SoC ADC driver");
 353 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 354 MODULE_LICENSE("GPL");
 355 MODULE_ALIAS("platform:jz4740-adc");