root/drivers/gpio/gpio-intel-mid.c

DEFINITIONS

1. gpio_reg
2. gpio_reg_2bit
3. intel_gpio_request
4. intel_gpio_get
5. intel_gpio_set
6. intel_gpio_direction_input
7. intel_gpio_direction_output
8. intel_mid_irq_type
9. intel_mid_irq_unmask
10. intel_mid_irq_mask
11. intel_mid_irq_handler
12. intel_mid_irq_init_hw
13. intel_gpio_runtime_idle
14. intel_gpio_probe

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Intel MID GPIO driver
   4  *
   5  * Copyright (c) 2008-2014,2016 Intel Corporation.
   6  */
   7 
   8 /* Supports:
   9  * Moorestown platform Langwell chip.
  10  * Medfield platform Penwell chip.
  11  * Clovertrail platform Cloverview chip.
  12  */
  13 
  14 #include <linux/delay.h>
  15 #include <linux/gpio/driver.h>
  16 #include <linux/init.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/io.h>
  19 #include <linux/kernel.h>
  20 #include <linux/pci.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/pm_runtime.h>
  23 #include <linux/slab.h>
  24 #include <linux/stddef.h>
  25 
  26 #define INTEL_MID_IRQ_TYPE_EDGE         (1 << 0)
  27 #define INTEL_MID_IRQ_TYPE_LEVEL        (1 << 1)
  28 
  29 /*
  30  * Langwell chip has 64 pins and thus there are 2 32bit registers to control
  31  * each feature, while Penwell chip has 96 pins for each block, and need 3 32bit
  32  * registers to control them, so we only define the order here instead of a
  33  * structure, to get a bit offset for a pin (use GPDR as an example):
  34  *
  35  * nreg = ngpio / 32;
  36  * reg = offset / 32;
  37  * bit = offset % 32;
  38  * reg_addr = reg_base + GPDR * nreg * 4 + reg * 4;
  39  *
  40  * so the bit of reg_addr is to control pin offset's GPDR feature
  41 */
  42 
  43 enum GPIO_REG {
  44         GPLR = 0,       /* pin level read-only */
  45         GPDR,           /* pin direction */
  46         GPSR,           /* pin set */
  47         GPCR,           /* pin clear */
  48         GRER,           /* rising edge detect */
  49         GFER,           /* falling edge detect */
  50         GEDR,           /* edge detect result */
  51         GAFR,           /* alt function */
  52 };
  53 
  54 /* intel_mid gpio driver data */
  55 struct intel_mid_gpio_ddata {
  56         u16 ngpio;              /* number of gpio pins */
  57         u32 chip_irq_type;      /* chip interrupt type */
  58 };
  59 
  60 struct intel_mid_gpio {
  61         struct gpio_chip                chip;
  62         void __iomem                    *reg_base;
  63         spinlock_t                      lock;
  64         struct pci_dev                  *pdev;
  65 };
  66 
  67 static void __iomem *gpio_reg(struct gpio_chip *chip, unsigned offset,
  68                               enum GPIO_REG reg_type)
  69 {
  70         struct intel_mid_gpio *priv = gpiochip_get_data(chip);
  71         unsigned nreg = chip->ngpio / 32;
  72         u8 reg = offset / 32;
  73 
  74         return priv->reg_base + reg_type * nreg * 4 + reg * 4;
  75 }
  76 
  77 static void __iomem *gpio_reg_2bit(struct gpio_chip *chip, unsigned offset,
  78                                    enum GPIO_REG reg_type)
  79 {
  80         struct intel_mid_gpio *priv = gpiochip_get_data(chip);
  81         unsigned nreg = chip->ngpio / 32;
  82         u8 reg = offset / 16;
  83 
  84         return priv->reg_base + reg_type * nreg * 4 + reg * 4;
  85 }
  86 
  87 static int intel_gpio_request(struct gpio_chip *chip, unsigned offset)
  88 {
  89         void __iomem *gafr = gpio_reg_2bit(chip, offset, GAFR);
  90         u32 value = readl(gafr);
  91         int shift = (offset % 16) << 1, af = (value >> shift) & 3;
  92 
  93         if (af) {
  94                 value &= ~(3 << shift);
  95                 writel(value, gafr);
  96         }
  97         return 0;
  98 }
  99 
 100 static int intel_gpio_get(struct gpio_chip *chip, unsigned offset)
 101 {
 102         void __iomem *gplr = gpio_reg(chip, offset, GPLR);
 103 
 104         return !!(readl(gplr) & BIT(offset % 32));
 105 }
 106 
 107 static void intel_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 108 {
 109         void __iomem *gpsr, *gpcr;
 110 
 111         if (value) {
 112                 gpsr = gpio_reg(chip, offset, GPSR);
 113                 writel(BIT(offset % 32), gpsr);
 114         } else {
 115                 gpcr = gpio_reg(chip, offset, GPCR);
 116                 writel(BIT(offset % 32), gpcr);
 117         }
 118 }
 119 
 120 static int intel_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 121 {
 122         struct intel_mid_gpio *priv = gpiochip_get_data(chip);
 123         void __iomem *gpdr = gpio_reg(chip, offset, GPDR);
 124         u32 value;
 125         unsigned long flags;
 126 
 127         if (priv->pdev)
 128                 pm_runtime_get(&priv->pdev->dev);
 129 
 130         spin_lock_irqsave(&priv->lock, flags);
 131         value = readl(gpdr);
 132         value &= ~BIT(offset % 32);
 133         writel(value, gpdr);
 134         spin_unlock_irqrestore(&priv->lock, flags);
 135 
 136         if (priv->pdev)
 137                 pm_runtime_put(&priv->pdev->dev);
 138 
 139         return 0;
 140 }
 141 
 142 static int intel_gpio_direction_output(struct gpio_chip *chip,
 143                         unsigned offset, int value)
 144 {
 145         struct intel_mid_gpio *priv = gpiochip_get_data(chip);
 146         void __iomem *gpdr = gpio_reg(chip, offset, GPDR);
 147         unsigned long flags;
 148 
 149         intel_gpio_set(chip, offset, value);
 150 
 151         if (priv->pdev)
 152                 pm_runtime_get(&priv->pdev->dev);
 153 
 154         spin_lock_irqsave(&priv->lock, flags);
 155         value = readl(gpdr);
 156         value |= BIT(offset % 32);
 157         writel(value, gpdr);
 158         spin_unlock_irqrestore(&priv->lock, flags);
 159 
 160         if (priv->pdev)
 161                 pm_runtime_put(&priv->pdev->dev);
 162 
 163         return 0;
 164 }
 165 
 166 static int intel_mid_irq_type(struct irq_data *d, unsigned type)
 167 {
 168         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 169         struct intel_mid_gpio *priv = gpiochip_get_data(gc);
 170         u32 gpio = irqd_to_hwirq(d);
 171         unsigned long flags;
 172         u32 value;
 173         void __iomem *grer = gpio_reg(&priv->chip, gpio, GRER);
 174         void __iomem *gfer = gpio_reg(&priv->chip, gpio, GFER);
 175 
 176         if (gpio >= priv->chip.ngpio)
 177                 return -EINVAL;
 178 
 179         if (priv->pdev)
 180                 pm_runtime_get(&priv->pdev->dev);
 181 
 182         spin_lock_irqsave(&priv->lock, flags);
 183         if (type & IRQ_TYPE_EDGE_RISING)
 184                 value = readl(grer) | BIT(gpio % 32);
 185         else
 186                 value = readl(grer) & (~BIT(gpio % 32));
 187         writel(value, grer);
 188 
 189         if (type & IRQ_TYPE_EDGE_FALLING)
 190                 value = readl(gfer) | BIT(gpio % 32);
 191         else
 192                 value = readl(gfer) & (~BIT(gpio % 32));
 193         writel(value, gfer);
 194         spin_unlock_irqrestore(&priv->lock, flags);
 195 
 196         if (priv->pdev)
 197                 pm_runtime_put(&priv->pdev->dev);
 198 
 199         return 0;
 200 }
 201 
 202 static void intel_mid_irq_unmask(struct irq_data *d)
 203 {
 204 }
 205 
 206 static void intel_mid_irq_mask(struct irq_data *d)
 207 {
 208 }
 209 
 210 static struct irq_chip intel_mid_irqchip = {
 211         .name           = "INTEL_MID-GPIO",
 212         .irq_mask       = intel_mid_irq_mask,
 213         .irq_unmask     = intel_mid_irq_unmask,
 214         .irq_set_type   = intel_mid_irq_type,
 215 };
 216 
 217 static const struct intel_mid_gpio_ddata gpio_lincroft = {
 218         .ngpio = 64,
 219 };
 220 
 221 static const struct intel_mid_gpio_ddata gpio_penwell_aon = {
 222         .ngpio = 96,
 223         .chip_irq_type = INTEL_MID_IRQ_TYPE_EDGE,
 224 };
 225 
 226 static const struct intel_mid_gpio_ddata gpio_penwell_core = {
 227         .ngpio = 96,
 228         .chip_irq_type = INTEL_MID_IRQ_TYPE_EDGE,
 229 };
 230 
 231 static const struct intel_mid_gpio_ddata gpio_cloverview_aon = {
 232         .ngpio = 96,
 233         .chip_irq_type = INTEL_MID_IRQ_TYPE_EDGE | INTEL_MID_IRQ_TYPE_LEVEL,
 234 };
 235 
 236 static const struct intel_mid_gpio_ddata gpio_cloverview_core = {
 237         .ngpio = 96,
 238         .chip_irq_type = INTEL_MID_IRQ_TYPE_EDGE,
 239 };
 240 
 241 static const struct pci_device_id intel_gpio_ids[] = {
 242         {
 243                 /* Lincroft */
 244                 PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x080f),
 245                 .driver_data = (kernel_ulong_t)&gpio_lincroft,
 246         },
 247         {
 248                 /* Penwell AON */
 249                 PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081f),
 250                 .driver_data = (kernel_ulong_t)&gpio_penwell_aon,
 251         },
 252         {
 253                 /* Penwell Core */
 254                 PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081a),
 255                 .driver_data = (kernel_ulong_t)&gpio_penwell_core,
 256         },
 257         {
 258                 /* Cloverview Aon */
 259                 PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x08eb),
 260                 .driver_data = (kernel_ulong_t)&gpio_cloverview_aon,
 261         },
 262         {
 263                 /* Cloverview Core */
 264                 PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x08f7),
 265                 .driver_data = (kernel_ulong_t)&gpio_cloverview_core,
 266         },
 267         { }
 268 };
 269 
 270 static void intel_mid_irq_handler(struct irq_desc *desc)
 271 {
 272         struct gpio_chip *gc = irq_desc_get_handler_data(desc);
 273         struct intel_mid_gpio *priv = gpiochip_get_data(gc);
 274         struct irq_data *data = irq_desc_get_irq_data(desc);
 275         struct irq_chip *chip = irq_data_get_irq_chip(data);
 276         u32 base, gpio, mask;
 277         unsigned long pending;
 278         void __iomem *gedr;
 279 
 280         /* check GPIO controller to check which pin triggered the interrupt */
 281         for (base = 0; base < priv->chip.ngpio; base += 32) {
 282                 gedr = gpio_reg(&priv->chip, base, GEDR);
 283                 while ((pending = readl(gedr))) {
 284                         gpio = __ffs(pending);
 285                         mask = BIT(gpio);
 286                         /* Clear before handling so we can't lose an edge */
 287                         writel(mask, gedr);
 288                         generic_handle_irq(irq_find_mapping(gc->irq.domain,
 289                                                             base + gpio));
 290                 }
 291         }
 292 
 293         chip->irq_eoi(data);
 294 }
 295 
 296 static int intel_mid_irq_init_hw(struct gpio_chip *chip)
 297 {
 298         struct intel_mid_gpio *priv = gpiochip_get_data(chip);
 299         void __iomem *reg;
 300         unsigned base;
 301 
 302         for (base = 0; base < priv->chip.ngpio; base += 32) {
 303                 /* Clear the rising-edge detect register */
 304                 reg = gpio_reg(&priv->chip, base, GRER);
 305                 writel(0, reg);
 306                 /* Clear the falling-edge detect register */
 307                 reg = gpio_reg(&priv->chip, base, GFER);
 308                 writel(0, reg);
 309                 /* Clear the edge detect status register */
 310                 reg = gpio_reg(&priv->chip, base, GEDR);
 311                 writel(~0, reg);
 312         }
 313 
 314         return 0;
 315 }
 316 
 317 static int __maybe_unused intel_gpio_runtime_idle(struct device *dev)
 318 {
 319         int err = pm_schedule_suspend(dev, 500);
 320         return err ?: -EBUSY;
 321 }
 322 
 323 static const struct dev_pm_ops intel_gpio_pm_ops = {
 324         SET_RUNTIME_PM_OPS(NULL, NULL, intel_gpio_runtime_idle)
 325 };
 326 
 327 static int intel_gpio_probe(struct pci_dev *pdev,
 328                           const struct pci_device_id *id)
 329 {
 330         void __iomem *base;
 331         struct intel_mid_gpio *priv;
 332         u32 gpio_base;
 333         u32 irq_base;
 334         int retval;
 335         struct gpio_irq_chip *girq;
 336         struct intel_mid_gpio_ddata *ddata =
 337                                 (struct intel_mid_gpio_ddata *)id->driver_data;
 338 
 339         retval = pcim_enable_device(pdev);
 340         if (retval)
 341                 return retval;
 342 
 343         retval = pcim_iomap_regions(pdev, 1 << 0 | 1 << 1, pci_name(pdev));
 344         if (retval) {
 345                 dev_err(&pdev->dev, "I/O memory mapping error\n");
 346                 return retval;
 347         }
 348 
 349         base = pcim_iomap_table(pdev)[1];
 350 
 351         irq_base = readl(base);
 352         gpio_base = readl(sizeof(u32) + base);
 353 
 354         /* release the IO mapping, since we already get the info from bar1 */
 355         pcim_iounmap_regions(pdev, 1 << 1);
 356 
 357         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 358         if (!priv)
 359                 return -ENOMEM;
 360 
 361         priv->reg_base = pcim_iomap_table(pdev)[0];
 362         priv->chip.label = dev_name(&pdev->dev);
 363         priv->chip.parent = &pdev->dev;
 364         priv->chip.request = intel_gpio_request;
 365         priv->chip.direction_input = intel_gpio_direction_input;
 366         priv->chip.direction_output = intel_gpio_direction_output;
 367         priv->chip.get = intel_gpio_get;
 368         priv->chip.set = intel_gpio_set;
 369         priv->chip.base = gpio_base;
 370         priv->chip.ngpio = ddata->ngpio;
 371         priv->chip.can_sleep = false;
 372         priv->pdev = pdev;
 373 
 374         spin_lock_init(&priv->lock);
 375 
 376         girq = &priv->chip.irq;
 377         girq->chip = &intel_mid_irqchip;
 378         girq->init_hw = intel_mid_irq_init_hw;
 379         girq->parent_handler = intel_mid_irq_handler;
 380         girq->num_parents = 1;
 381         girq->parents = devm_kcalloc(&pdev->dev, girq->num_parents,
 382                                      sizeof(*girq->parents),
 383                                      GFP_KERNEL);
 384         if (!girq->parents)
 385                 return -ENOMEM;
 386         girq->parents[0] = pdev->irq;
 387         girq->first = irq_base;
 388         girq->default_type = IRQ_TYPE_NONE;
 389         girq->handler = handle_simple_irq;
 390 
 391         pci_set_drvdata(pdev, priv);
 392 
 393         retval = devm_gpiochip_add_data(&pdev->dev, &priv->chip, priv);
 394         if (retval) {
 395                 dev_err(&pdev->dev, "gpiochip_add error %d\n", retval);
 396                 return retval;
 397         }
 398 
 399         pm_runtime_put_noidle(&pdev->dev);
 400         pm_runtime_allow(&pdev->dev);
 401 
 402         return 0;
 403 }
 404 
 405 static struct pci_driver intel_gpio_driver = {
 406         .name           = "intel_mid_gpio",
 407         .id_table       = intel_gpio_ids,
 408         .probe          = intel_gpio_probe,
 409         .driver         = {
 410                 .pm     = &intel_gpio_pm_ops,
 411         },
 412 };
 413 
 414 builtin_pci_driver(intel_gpio_driver);