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/io.h>
  20 #include <linux/irq.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/slab.h>
  26 #include <linux/spinlock.h>
  27
  28 #include <linux/clk.h>
  29 #include <linux/mfd/core.h>
  30
  31 #include <linux/jz4740-adc.h>
  32
  33
  34 #define JZ_REG_ADC_ENABLE       0x00
  35 #define JZ_REG_ADC_CFG          0x04
  36 #define JZ_REG_ADC_CTRL         0x08
  37 #define JZ_REG_ADC_STATUS       0x0c
  38
  39 #define JZ_REG_ADC_TOUCHSCREEN_BASE     0x10
  40 #define JZ_REG_ADC_BATTERY_BASE 0x1c
  41 #define JZ_REG_ADC_HWMON_BASE   0x20
  42
  43 #define JZ_ADC_ENABLE_TOUCH     BIT(2)
  44 #define JZ_ADC_ENABLE_BATTERY   BIT(1)
  45 #define JZ_ADC_ENABLE_ADCIN     BIT(0)
  46
  47 enum {
  48         JZ_ADC_IRQ_ADCIN = 0,
  49         JZ_ADC_IRQ_BATTERY,
  50         JZ_ADC_IRQ_TOUCH,
  51         JZ_ADC_IRQ_PENUP,
  52         JZ_ADC_IRQ_PENDOWN,
  53 };
  54
  55 struct jz4740_adc {
  56         struct resource *mem;
  57         void __iomem *base;
  58
  59         int irq;
  60         struct irq_chip_generic *gc;
  61
  62         struct clk *clk;
  63         atomic_t clk_ref;
  64
  65         spinlock_t lock;
  66 };
  67
  68 static void jz4740_adc_irq_demux(unsigned int irq, struct irq_desc *desc)
  69 {
  70         struct irq_chip_generic *gc = irq_desc_get_handler_data(desc);
  71         uint8_t status;
  72         unsigned int i;
  73
  74         status = readb(gc->reg_base + JZ_REG_ADC_STATUS);
  75
  76         for (i = 0; i < 5; ++i) {
  77                 if (status & BIT(i))
  78                         generic_handle_irq(gc->irq_base + i);
  79         }
  80 }
  81
  82
  83 /* Refcounting for the ADC clock is done in here instead of in the clock
  84  * framework, because it is the only clock which is shared between multiple
  85  * devices and thus is the only clock which needs refcounting */
  86 static inline void jz4740_adc_clk_enable(struct jz4740_adc *adc)
  87 {
  88         if (atomic_inc_return(&adc->clk_ref) == 1)
  89                 clk_prepare_enable(adc->clk);
  90 }
  91
  92 static inline void jz4740_adc_clk_disable(struct jz4740_adc *adc)
  93 {
  94         if (atomic_dec_return(&adc->clk_ref) == 0)
  95                 clk_disable_unprepare(adc->clk);
  96 }
  97
  98 static inline void jz4740_adc_set_enabled(struct jz4740_adc *adc, int engine,
  99         bool enabled)
 100 {
 101         unsigned long flags;
 102         uint8_t val;
 103
 104         spin_lock_irqsave(&adc->lock, flags);
 105
 106         val = readb(adc->base + JZ_REG_ADC_ENABLE);
 107         if (enabled)
 108                 val |= BIT(engine);
 109         else
 110                 val &= ~BIT(engine);
 111         writeb(val, adc->base + JZ_REG_ADC_ENABLE);
 112
 113         spin_unlock_irqrestore(&adc->lock, flags);
 114 }
 115
 116 static int jz4740_adc_cell_enable(struct platform_device *pdev)
 117 {
 118         struct jz4740_adc *adc = dev_get_drvdata(pdev->dev.parent);
 119
 120         jz4740_adc_clk_enable(adc);
 121         jz4740_adc_set_enabled(adc, pdev->id, true);
 122
 123         return 0;
 124 }
 125
 126 static int jz4740_adc_cell_disable(struct platform_device *pdev)
 127 {
 128         struct jz4740_adc *adc = dev_get_drvdata(pdev->dev.parent);
 129
 130         jz4740_adc_set_enabled(adc, pdev->id, false);
 131         jz4740_adc_clk_disable(adc);
 132
 133         return 0;
 134 }
 135
 136 int jz4740_adc_set_config(struct device *dev, uint32_t mask, uint32_t val)
 137 {
 138         struct jz4740_adc *adc = dev_get_drvdata(dev);
 139         unsigned long flags;
 140         uint32_t cfg;
 141
 142         if (!adc)
 143                 return -ENODEV;
 144
 145         spin_lock_irqsave(&adc->lock, flags);
 146
 147         cfg = readl(adc->base + JZ_REG_ADC_CFG);
 148
 149         cfg &= ~mask;
 150         cfg |= val;
 151
 152         writel(cfg, adc->base + JZ_REG_ADC_CFG);
 153
 154         spin_unlock_irqrestore(&adc->lock, flags);
 155
 156         return 0;
 157 }
 158 EXPORT_SYMBOL_GPL(jz4740_adc_set_config);
 159
 160 static struct resource jz4740_hwmon_resources[] = {
 161         {
 162                 .start = JZ_ADC_IRQ_ADCIN,
 163                 .flags = IORESOURCE_IRQ,
 164         },
 165         {
 166                 .start  = JZ_REG_ADC_HWMON_BASE,
 167                 .end    = JZ_REG_ADC_HWMON_BASE + 3,
 168                 .flags  = IORESOURCE_MEM,
 169         },
 170 };
 171
 172 static struct resource jz4740_battery_resources[] = {
 173         {
 174                 .start = JZ_ADC_IRQ_BATTERY,
 175                 .flags = IORESOURCE_IRQ,
 176         },
 177         {
 178                 .start  = JZ_REG_ADC_BATTERY_BASE,
 179                 .end    = JZ_REG_ADC_BATTERY_BASE + 3,
 180                 .flags  = IORESOURCE_MEM,
 181         },
 182 };
 183
 184 static struct mfd_cell jz4740_adc_cells[] = {
 185         {
 186                 .id = 0,
 187                 .name = "jz4740-hwmon",
 188                 .num_resources = ARRAY_SIZE(jz4740_hwmon_resources),
 189                 .resources = jz4740_hwmon_resources,
 190
 191                 .enable = jz4740_adc_cell_enable,
 192                 .disable = jz4740_adc_cell_disable,
 193         },
 194         {
 195                 .id = 1,
 196                 .name = "jz4740-battery",
 197                 .num_resources = ARRAY_SIZE(jz4740_battery_resources),
 198                 .resources = jz4740_battery_resources,
 199
 200                 .enable = jz4740_adc_cell_enable,
 201                 .disable = jz4740_adc_cell_disable,
 202         },
 203 };
 204
 205 static int jz4740_adc_probe(struct platform_device *pdev)
 206 {
 207         struct irq_chip_generic *gc;
 208         struct irq_chip_type *ct;
 209         struct jz4740_adc *adc;
 210         struct resource *mem_base;
 211         int ret;
 212         int irq_base;
 213
 214         adc = devm_kzalloc(&pdev->dev, sizeof(*adc), GFP_KERNEL);
 215         if (!adc) {
 216                 dev_err(&pdev->dev, "Failed to allocate driver structure\n");
 217                 return -ENOMEM;
 218         }
 219
 220         adc->irq = platform_get_irq(pdev, 0);
 221         if (adc->irq < 0) {
 222                 ret = adc->irq;
 223                 dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
 224                 return ret;
 225         }
 226
 227         irq_base = platform_get_irq(pdev, 1);
 228         if (irq_base < 0) {
 229                 dev_err(&pdev->dev, "Failed to get irq base: %d\n", irq_base);
 230                 return irq_base;
 231         }
 232
 233         mem_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 234         if (!mem_base) {
 235                 dev_err(&pdev->dev, "Failed to get platform mmio resource\n");
 236                 return -ENOENT;
 237         }
 238
 239         /* Only request the shared registers for the MFD driver */
 240         adc->mem = request_mem_region(mem_base->start, JZ_REG_ADC_STATUS,
 241                                         pdev->name);
 242         if (!adc->mem) {
 243                 dev_err(&pdev->dev, "Failed to request mmio memory region\n");
 244                 return -EBUSY;
 245         }
 246
 247         adc->base = ioremap_nocache(adc->mem->start, resource_size(adc->mem));
 248         if (!adc->base) {
 249                 ret = -EBUSY;
 250                 dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
 251                 goto err_release_mem_region;
 252         }
 253
 254         adc->clk = clk_get(&pdev->dev, "adc");
 255         if (IS_ERR(adc->clk)) {
 256                 ret = PTR_ERR(adc->clk);
 257                 dev_err(&pdev->dev, "Failed to get clock: %d\n", ret);
 258                 goto err_iounmap;
 259         }
 260
 261         spin_lock_init(&adc->lock);
 262         atomic_set(&adc->clk_ref, 0);
 263
 264         platform_set_drvdata(pdev, adc);
 265
 266         gc = irq_alloc_generic_chip("INTC", 1, irq_base, adc->base,
 267                 handle_level_irq);
 268
 269         ct = gc->chip_types;
 270         ct->regs.mask = JZ_REG_ADC_CTRL;
 271         ct->regs.ack = JZ_REG_ADC_STATUS;
 272         ct->chip.irq_mask = irq_gc_mask_set_bit;
 273         ct->chip.irq_unmask = irq_gc_mask_clr_bit;
 274         ct->chip.irq_ack = irq_gc_ack_set_bit;
 275
 276         irq_setup_generic_chip(gc, IRQ_MSK(5), 0, 0, IRQ_NOPROBE | IRQ_LEVEL);
 277
 278         adc->gc = gc;
 279
 280         irq_set_handler_data(adc->irq, gc);
 281         irq_set_chained_handler(adc->irq, jz4740_adc_irq_demux);
 282
 283         writeb(0x00, adc->base + JZ_REG_ADC_ENABLE);
 284         writeb(0xff, adc->base + JZ_REG_ADC_CTRL);
 285
 286         ret = mfd_add_devices(&pdev->dev, 0, jz4740_adc_cells,
 287                               ARRAY_SIZE(jz4740_adc_cells), mem_base,
 288                               irq_base, NULL);
 289         if (ret < 0)
 290                 goto err_clk_put;
 291
 292         return 0;
 293
 294 err_clk_put:
 295         clk_put(adc->clk);
 296 err_iounmap:
 297         iounmap(adc->base);
 298 err_release_mem_region:
 299         release_mem_region(adc->mem->start, resource_size(adc->mem));
 300         return ret;
 301 }
 302
 303 static int jz4740_adc_remove(struct platform_device *pdev)
 304 {
 305         struct jz4740_adc *adc = platform_get_drvdata(pdev);
 306
 307         mfd_remove_devices(&pdev->dev);
 308
 309         irq_remove_generic_chip(adc->gc, IRQ_MSK(5), IRQ_NOPROBE | IRQ_LEVEL, 0);
 310         kfree(adc->gc);
 311         irq_set_handler_data(adc->irq, NULL);
 312         irq_set_chained_handler(adc->irq, NULL);
 313
 314         iounmap(adc->base);
 315         release_mem_region(adc->mem->start, resource_size(adc->mem));
 316
 317         clk_put(adc->clk);
 318
 319         return 0;
 320 }
 321
 322 static struct platform_driver jz4740_adc_driver = {
 323         .probe  = jz4740_adc_probe,
 324         .remove = jz4740_adc_remove,
 325         .driver = {
 326                 .name = "jz4740-adc",
 327                 .owner = THIS_MODULE,
 328         },
 329 };
 330
 331 module_platform_driver(jz4740_adc_driver);
 332
 333 MODULE_DESCRIPTION("JZ4740 SoC ADC driver");
 334 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 335 MODULE_LICENSE("GPL");
 336 MODULE_ALIAS("platform:jz4740-adc");