drivers/usb/misc/brcmstb-usb-pinmap.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (c) 2020, Broadcom */
   3
   4 #include <linux/init.h>
   5 #include <linux/types.h>
   6 #include <linux/module.h>
   7 #include <linux/platform_device.h>
   8 #include <linux/interrupt.h>
   9 #include <linux/io.h>
  10 #include <linux/device.h>
  11 #include <linux/of.h>
  12 #include <linux/kernel.h>
  13 #include <linux/kdebug.h>
  14 #include <linux/gpio/consumer.h>
  15
  16 struct out_pin {
  17         u32 enable_mask;
  18         u32 value_mask;
  19         u32 changed_mask;
  20         u32 clr_changed_mask;
  21         struct gpio_desc *gpiod;
  22         const char *name;
  23 };
  24
  25 struct in_pin {
  26         u32 enable_mask;
  27         u32 value_mask;
  28         struct gpio_desc *gpiod;
  29         const char *name;
  30         struct brcmstb_usb_pinmap_data *pdata;
  31 };
  32
  33 struct brcmstb_usb_pinmap_data {
  34         void __iomem *regs;
  35         int in_count;
  36         struct in_pin *in_pins;
  37         int out_count;
  38         struct out_pin *out_pins;
  39 };
  40
  41
  42 static void pinmap_set(void __iomem *reg, u32 mask)
  43 {
  44         u32 val;
  45
  46         val = readl(reg);
  47         val |= mask;
  48         writel(val, reg);
  49 }
  50
  51 static void pinmap_unset(void __iomem *reg, u32 mask)
  52 {
  53         u32 val;
  54
  55         val = readl(reg);
  56         val &= ~mask;
  57         writel(val, reg);
  58 }
  59
  60 static void sync_in_pin(struct in_pin *pin)
  61 {
  62         u32 val;
  63
  64         val = gpiod_get_value(pin->gpiod);
  65         if (val)
  66                 pinmap_set(pin->pdata->regs, pin->value_mask);
  67         else
  68                 pinmap_unset(pin->pdata->regs, pin->value_mask);
  69 }
  70
  71 /*
  72  * Interrupt from override register, propagate from override bit
  73  * to GPIO.
  74  */
  75 static irqreturn_t brcmstb_usb_pinmap_ovr_isr(int irq, void *dev_id)
  76 {
  77         struct brcmstb_usb_pinmap_data *pdata = dev_id;
  78         struct out_pin *pout;
  79         u32 val;
  80         u32 bit;
  81         int x;
  82
  83         pr_debug("%s: reg: 0x%x\n", __func__, readl(pdata->regs));
  84         pout = pdata->out_pins;
  85         for (x = 0; x < pdata->out_count; x++) {
  86                 val = readl(pdata->regs);
  87                 if (val & pout->changed_mask) {
  88                         pinmap_set(pdata->regs, pout->clr_changed_mask);
  89                         pinmap_unset(pdata->regs, pout->clr_changed_mask);
  90                         bit = val & pout->value_mask;
  91                         gpiod_set_value(pout->gpiod, bit ? 1 : 0);
  92                         pr_debug("%s: %s bit changed state to %d\n",
  93                                  __func__, pout->name, bit ? 1 : 0);
  94                 }
  95         }
  96         return IRQ_HANDLED;
  97 }
  98
  99 /*
 100  * Interrupt from GPIO, propagate from GPIO to override bit.
 101  */
 102 static irqreturn_t brcmstb_usb_pinmap_gpio_isr(int irq, void *dev_id)
 103 {
 104         struct in_pin *pin = dev_id;
 105
 106         pr_debug("%s: %s pin changed state\n", __func__, pin->name);
 107         sync_in_pin(pin);
 108         return IRQ_HANDLED;
 109 }
 110
 111
 112 static void get_pin_counts(struct device_node *dn, int *in_count,
 113                            int *out_count)
 114 {
 115         int in;
 116         int out;
 117
 118         *in_count = 0;
 119         *out_count = 0;
 120         in = of_property_count_strings(dn, "brcm,in-functions");
 121         if (in < 0)
 122                 return;
 123         out = of_property_count_strings(dn, "brcm,out-functions");
 124         if (out < 0)
 125                 return;
 126         *in_count = in;
 127         *out_count = out;
 128 }
 129
 130 static int parse_pins(struct device *dev, struct device_node *dn,
 131                       struct brcmstb_usb_pinmap_data *pdata)
 132 {
 133         struct out_pin *pout;
 134         struct in_pin *pin;
 135         int index;
 136         int res;
 137         int x;
 138
 139         pin = pdata->in_pins;
 140         for (x = 0, index = 0; x < pdata->in_count; x++) {
 141                 pin->gpiod = devm_gpiod_get_index(dev, "in", x, GPIOD_IN);
 142                 if (IS_ERR(pin->gpiod)) {
 143                         dev_err(dev, "Error getting gpio %s\n", pin->name);
 144                         return PTR_ERR(pin->gpiod);
 145
 146                 }
 147                 res = of_property_read_string_index(dn, "brcm,in-functions", x,
 148                                                     &pin->name);
 149                 if (res < 0) {
 150                         dev_err(dev, "Error getting brcm,in-functions for %s\n",
 151                                 pin->name);
 152                         return res;
 153                 }
 154                 res = of_property_read_u32_index(dn, "brcm,in-masks", index++,
 155                                                  &pin->enable_mask);
 156                 if (res < 0) {
 157                         dev_err(dev, "Error getting 1st brcm,in-masks for %s\n",
 158                                 pin->name);
 159                         return res;
 160                 }
 161                 res = of_property_read_u32_index(dn, "brcm,in-masks", index++,
 162                                                  &pin->value_mask);
 163                 if (res < 0) {
 164                         dev_err(dev, "Error getting 2nd brcm,in-masks for %s\n",
 165                                 pin->name);
 166                         return res;
 167                 }
 168                 pin->pdata = pdata;
 169                 pin++;
 170         }
 171         pout = pdata->out_pins;
 172         for (x = 0, index = 0; x < pdata->out_count; x++) {
 173                 pout->gpiod = devm_gpiod_get_index(dev, "out", x,
 174                                                    GPIOD_OUT_HIGH);
 175                 if (IS_ERR(pout->gpiod)) {
 176                         dev_err(dev, "Error getting gpio %s\n", pin->name);
 177                         return PTR_ERR(pout->gpiod);
 178                 }
 179                 res = of_property_read_string_index(dn, "brcm,out-functions", x,
 180                                                     &pout->name);
 181                 if (res < 0) {
 182                         dev_err(dev, "Error getting brcm,out-functions for %s\n",
 183                                 pout->name);
 184                         return res;
 185                 }
 186                 res = of_property_read_u32_index(dn, "brcm,out-masks", index++,
 187                                                  &pout->enable_mask);
 188                 if (res < 0) {
 189                         dev_err(dev, "Error getting 1st brcm,out-masks for %s\n",
 190                                 pout->name);
 191                         return res;
 192                 }
 193                 res = of_property_read_u32_index(dn, "brcm,out-masks", index++,
 194                                                  &pout->value_mask);
 195                 if (res < 0) {
 196                         dev_err(dev, "Error getting 2nd brcm,out-masks for %s\n",
 197                                 pout->name);
 198                         return res;
 199                 }
 200                 res = of_property_read_u32_index(dn, "brcm,out-masks", index++,
 201                                                  &pout->changed_mask);
 202                 if (res < 0) {
 203                         dev_err(dev, "Error getting 3rd brcm,out-masks for %s\n",
 204                                 pout->name);
 205                         return res;
 206                 }
 207                 res = of_property_read_u32_index(dn, "brcm,out-masks", index++,
 208                                                  &pout->clr_changed_mask);
 209                 if (res < 0) {
 210                         dev_err(dev, "Error getting 4th out-masks for %s\n",
 211                                 pout->name);
 212                         return res;
 213                 }
 214                 pout++;
 215         }
 216         return 0;
 217 }
 218
 219 static void sync_all_pins(struct brcmstb_usb_pinmap_data *pdata)
 220 {
 221         struct out_pin *pout;
 222         struct in_pin *pin;
 223         int val;
 224         int x;
 225
 226         /*
 227          * Enable the override, clear any changed condition and
 228          * propagate the state to the GPIO for all out pins.
 229          */
 230         pout = pdata->out_pins;
 231         for (x = 0; x < pdata->out_count; x++) {
 232                 pinmap_set(pdata->regs, pout->enable_mask);
 233                 pinmap_set(pdata->regs, pout->clr_changed_mask);
 234                 pinmap_unset(pdata->regs, pout->clr_changed_mask);
 235                 val = readl(pdata->regs) & pout->value_mask;
 236                 gpiod_set_value(pout->gpiod, val ? 1 : 0);
 237                 pout++;
 238         }
 239
 240         /* sync and enable all in pins. */
 241         pin = pdata->in_pins;
 242         for (x = 0; x < pdata->in_count; x++) {
 243                 sync_in_pin(pin);
 244                 pinmap_set(pdata->regs, pin->enable_mask);
 245                 pin++;
 246         }
 247 }
 248
 249 static int __init brcmstb_usb_pinmap_probe(struct platform_device *pdev)
 250 {
 251         struct device_node *dn = pdev->dev.of_node;
 252         struct brcmstb_usb_pinmap_data *pdata;
 253         struct in_pin *pin;
 254         struct resource *r;
 255         int out_count;
 256         int in_count;
 257         int err;
 258         int irq;
 259         int x;
 260
 261         get_pin_counts(dn, &in_count, &out_count);
 262         if ((in_count + out_count) == 0)
 263                 return -EINVAL;
 264
 265         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 266         if (!r)
 267                 return -EINVAL;
 268
 269         pdata = devm_kzalloc(&pdev->dev,
 270                              sizeof(*pdata) +
 271                              (sizeof(struct in_pin) * in_count) +
 272                              (sizeof(struct out_pin) * out_count), GFP_KERNEL);
 273         if (!pdata)
 274                 return -ENOMEM;
 275
 276         pdata->in_count = in_count;
 277         pdata->out_count = out_count;
 278         pdata->in_pins = (struct in_pin *)(pdata + 1);
 279         pdata->out_pins = (struct out_pin *)(pdata->in_pins + in_count);
 280
 281         pdata->regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
 282         if (!pdata->regs)
 283                 return -ENOMEM;
 284         platform_set_drvdata(pdev, pdata);
 285
 286         err = parse_pins(&pdev->dev, dn, pdata);
 287         if (err)
 288                 return err;
 289
 290         sync_all_pins(pdata);
 291
 292         if (out_count) {
 293
 294                 /* Enable interrupt for out pins */
 295                 irq = platform_get_irq(pdev, 0);
 296                 err = devm_request_irq(&pdev->dev, irq,
 297                                        brcmstb_usb_pinmap_ovr_isr,
 298                                        IRQF_TRIGGER_RISING,
 299                                        pdev->name, pdata);
 300                 if (err < 0) {
 301                         dev_err(&pdev->dev, "Error requesting IRQ\n");
 302                         return err;
 303                 }
 304         }
 305
 306         for (x = 0, pin = pdata->in_pins; x < pdata->in_count; x++, pin++) {
 307                 irq = gpiod_to_irq(pin->gpiod);
 308                 if (irq < 0) {
 309                         dev_err(&pdev->dev, "Error getting IRQ for %s pin\n",
 310                                 pin->name);
 311                         return irq;
 312                 }
 313                 err = devm_request_irq(&pdev->dev, irq,
 314                                        brcmstb_usb_pinmap_gpio_isr,
 315                                        IRQF_SHARED | IRQF_TRIGGER_RISING |
 316                                        IRQF_TRIGGER_FALLING,
 317                                        pdev->name, pin);
 318                 if (err < 0) {
 319                         dev_err(&pdev->dev, "Error requesting IRQ for %s pin\n",
 320                                 pin->name);
 321                         return err;
 322                 }
 323         }
 324
 325         dev_dbg(&pdev->dev, "Driver probe succeeded\n");
 326         dev_dbg(&pdev->dev, "In pin count: %d, out pin count: %d\n",
 327                 pdata->in_count, pdata->out_count);
 328         return 0;
 329 }
 330
 331
 332 static const struct of_device_id brcmstb_usb_pinmap_of_match[] = {
 333         { .compatible = "brcm,usb-pinmap" },
 334         { },
 335 };
 336
 337 static struct platform_driver brcmstb_usb_pinmap_driver = {
 338         .driver = {
 339                 .name   = "brcm-usb-pinmap",
 340                 .of_match_table = brcmstb_usb_pinmap_of_match,
 341         },
 342 };
 343
 344 static int __init brcmstb_usb_pinmap_init(void)
 345 {
 346         return platform_driver_probe(&brcmstb_usb_pinmap_driver,
 347                                      brcmstb_usb_pinmap_probe);
 348 }
 349
 350 module_init(brcmstb_usb_pinmap_init);
 351 MODULE_AUTHOR("Al Cooper <alcooperx@gmail.com>");
 352 MODULE_DESCRIPTION("Broadcom USB Pinmap Driver");
 353 MODULE_LICENSE("GPL");