drivers/gpio/gpio-mlxbf2.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #include <linux/acpi.h>
   4 #include <linux/bitfield.h>
   5 #include <linux/bitops.h>
   6 #include <linux/device.h>
   7 #include <linux/gpio/driver.h>
   8 #include <linux/io.h>
   9 #include <linux/ioport.h>
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/pm.h>
  14 #include <linux/resource.h>
  15 #include <linux/spinlock.h>
  16 #include <linux/types.h>
  17
  18 /*
  19  * There are 3 YU GPIO blocks:
  20  * gpio[0]: HOST_GPIO0->HOST_GPIO31
  21  * gpio[1]: HOST_GPIO32->HOST_GPIO63
  22  * gpio[2]: HOST_GPIO64->HOST_GPIO69
  23  */
  24 #define MLXBF2_GPIO_MAX_PINS_PER_BLOCK 32
  25
  26 /*
  27  * arm_gpio_lock register:
  28  * bit[31]      lock status: active if set
  29  * bit[15:0]    set lock
  30  * The lock is enabled only if 0xd42f is written to this field
  31  */
  32 #define YU_ARM_GPIO_LOCK_ADDR           0x2801088
  33 #define YU_ARM_GPIO_LOCK_SIZE           0x8
  34 #define YU_LOCK_ACTIVE_BIT(val)         (val >> 31)
  35 #define YU_ARM_GPIO_LOCK_ACQUIRE        0xd42f
  36 #define YU_ARM_GPIO_LOCK_RELEASE        0x0
  37
  38 /*
  39  * gpio[x] block registers and their offset
  40  */
  41 #define YU_GPIO_DATAIN                  0x04
  42 #define YU_GPIO_MODE1                   0x08
  43 #define YU_GPIO_MODE0                   0x0c
  44 #define YU_GPIO_DATASET                 0x14
  45 #define YU_GPIO_DATACLEAR               0x18
  46 #define YU_GPIO_MODE1_CLEAR             0x50
  47 #define YU_GPIO_MODE0_SET               0x54
  48 #define YU_GPIO_MODE0_CLEAR             0x58
  49
  50 #ifdef CONFIG_PM
  51 struct mlxbf2_gpio_context_save_regs {
  52         u32 gpio_mode0;
  53         u32 gpio_mode1;
  54 };
  55 #endif
  56
  57 /* BlueField-2 gpio block context structure. */
  58 struct mlxbf2_gpio_context {
  59         struct gpio_chip gc;
  60
  61         /* YU GPIO blocks address */
  62         void __iomem *gpio_io;
  63
  64 #ifdef CONFIG_PM
  65         struct mlxbf2_gpio_context_save_regs *csave_regs;
  66 #endif
  67 };
  68
  69 /* BlueField-2 gpio shared structure. */
  70 struct mlxbf2_gpio_param {
  71         void __iomem *io;
  72         struct resource *res;
  73         struct mutex *lock;
  74 };
  75
  76 static struct resource yu_arm_gpio_lock_res = {
  77         .start = YU_ARM_GPIO_LOCK_ADDR,
  78         .end   = YU_ARM_GPIO_LOCK_ADDR + YU_ARM_GPIO_LOCK_SIZE - 1,
  79         .name  = "YU_ARM_GPIO_LOCK",
  80 };
  81
  82 static DEFINE_MUTEX(yu_arm_gpio_lock_mutex);
  83
  84 static struct mlxbf2_gpio_param yu_arm_gpio_lock_param = {
  85         .res = &yu_arm_gpio_lock_res,
  86         .lock = &yu_arm_gpio_lock_mutex,
  87 };
  88
  89 /* Request memory region and map yu_arm_gpio_lock resource */
  90 static int mlxbf2_gpio_get_lock_res(struct platform_device *pdev)
  91 {
  92         struct device *dev = &pdev->dev;
  93         struct resource *res;
  94         resource_size_t size;
  95         int ret = 0;
  96
  97         mutex_lock(yu_arm_gpio_lock_param.lock);
  98
  99         /* Check if the memory map already exists */
 100         if (yu_arm_gpio_lock_param.io)
 101                 goto exit;
 102
 103         res = yu_arm_gpio_lock_param.res;
 104         size = resource_size(res);
 105
 106         if (!devm_request_mem_region(dev, res->start, size, res->name)) {
 107                 ret = -EFAULT;
 108                 goto exit;
 109         }
 110
 111         yu_arm_gpio_lock_param.io = devm_ioremap(dev, res->start, size);
 112         if (!yu_arm_gpio_lock_param.io)
 113                 ret = -ENOMEM;
 114
 115 exit:
 116         mutex_unlock(yu_arm_gpio_lock_param.lock);
 117
 118         return ret;
 119 }
 120
 121 /*
 122  * Acquire the YU arm_gpio_lock to be able to change the direction
 123  * mode. If the lock_active bit is already set, return an error.
 124  */
 125 static int mlxbf2_gpio_lock_acquire(struct mlxbf2_gpio_context *gs)
 126 {
 127         u32 arm_gpio_lock_val;
 128
 129         spin_lock(&gs->gc.bgpio_lock);
 130         mutex_lock(yu_arm_gpio_lock_param.lock);
 131
 132         arm_gpio_lock_val = readl(yu_arm_gpio_lock_param.io);
 133
 134         /*
 135          * When lock active bit[31] is set, ModeX is write enabled
 136          */
 137         if (YU_LOCK_ACTIVE_BIT(arm_gpio_lock_val)) {
 138                 mutex_unlock(yu_arm_gpio_lock_param.lock);
 139                 spin_unlock(&gs->gc.bgpio_lock);
 140                 return -EINVAL;
 141         }
 142
 143         writel(YU_ARM_GPIO_LOCK_ACQUIRE, yu_arm_gpio_lock_param.io);
 144
 145         return 0;
 146 }
 147
 148 /*
 149  * Release the YU arm_gpio_lock after changing the direction mode.
 150  */
 151 static void mlxbf2_gpio_lock_release(struct mlxbf2_gpio_context *gs)
 152 {
 153         writel(YU_ARM_GPIO_LOCK_RELEASE, yu_arm_gpio_lock_param.io);
 154         mutex_unlock(yu_arm_gpio_lock_param.lock);
 155         spin_unlock(&gs->gc.bgpio_lock);
 156 }
 157
 158 /*
 159  * mode0 and mode1 are both locked by the gpio_lock field.
 160  *
 161  * Together, mode0 and mode1 define the gpio Mode dependeing also
 162  * on Reg_DataOut.
 163  *
 164  * {mode1,mode0}:{Reg_DataOut=0,Reg_DataOut=1}->{DataOut=0,DataOut=1}
 165  *
 166  * {0,0}:Reg_DataOut{0,1}->{Z,Z} Input PAD
 167  * {0,1}:Reg_DataOut{0,1}->{0,1} Full drive Output PAD
 168  * {1,0}:Reg_DataOut{0,1}->{0,Z} 0-set PAD to low, 1-float
 169  * {1,1}:Reg_DataOut{0,1}->{Z,1} 0-float, 1-set PAD to high
 170  */
 171
 172 /*
 173  * Set input direction:
 174  * {mode1,mode0} = {0,0}
 175  */
 176 static int mlxbf2_gpio_direction_input(struct gpio_chip *chip,
 177                                        unsigned int offset)
 178 {
 179         struct mlxbf2_gpio_context *gs = gpiochip_get_data(chip);
 180         int ret;
 181
 182         /*
 183          * Although the arm_gpio_lock was set in the probe function, check again
 184          * if it is still enabled to be able to write to the ModeX registers.
 185          */
 186         ret = mlxbf2_gpio_lock_acquire(gs);
 187         if (ret < 0)
 188                 return ret;
 189
 190         writel(BIT(offset), gs->gpio_io + YU_GPIO_MODE0_CLEAR);
 191         writel(BIT(offset), gs->gpio_io + YU_GPIO_MODE1_CLEAR);
 192
 193         mlxbf2_gpio_lock_release(gs);
 194
 195         return ret;
 196 }
 197
 198 /*
 199  * Set output direction:
 200  * {mode1,mode0} = {0,1}
 201  */
 202 static int mlxbf2_gpio_direction_output(struct gpio_chip *chip,
 203                                         unsigned int offset,
 204                                         int value)
 205 {
 206         struct mlxbf2_gpio_context *gs = gpiochip_get_data(chip);
 207         int ret = 0;
 208
 209         /*
 210          * Although the arm_gpio_lock was set in the probe function,
 211          * check again it is still enabled to be able to write to the
 212          * ModeX registers.
 213          */
 214         ret = mlxbf2_gpio_lock_acquire(gs);
 215         if (ret < 0)
 216                 return ret;
 217
 218         writel(BIT(offset), gs->gpio_io + YU_GPIO_MODE1_CLEAR);
 219         writel(BIT(offset), gs->gpio_io + YU_GPIO_MODE0_SET);
 220
 221         mlxbf2_gpio_lock_release(gs);
 222
 223         return ret;
 224 }
 225
 226 /* BlueField-2 GPIO driver initialization routine. */
 227 static int
 228 mlxbf2_gpio_probe(struct platform_device *pdev)
 229 {
 230         struct mlxbf2_gpio_context *gs;
 231         struct device *dev = &pdev->dev;
 232         struct gpio_chip *gc;
 233         struct resource *res;
 234         unsigned int npins;
 235         int ret;
 236
 237         gs = devm_kzalloc(dev, sizeof(*gs), GFP_KERNEL);
 238         if (!gs)
 239                 return -ENOMEM;
 240
 241         /* YU GPIO block address */
 242         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 243         if (!res)
 244                 return -ENODEV;
 245
 246         gs->gpio_io = devm_ioremap(dev, res->start, resource_size(res));
 247         if (!gs->gpio_io)
 248                 return -ENOMEM;
 249
 250         ret = mlxbf2_gpio_get_lock_res(pdev);
 251         if (ret) {
 252                 dev_err(dev, "Failed to get yu_arm_gpio_lock resource\n");
 253                 return ret;
 254         }
 255
 256         if (device_property_read_u32(dev, "npins", &npins))
 257                 npins = MLXBF2_GPIO_MAX_PINS_PER_BLOCK;
 258
 259         gc = &gs->gc;
 260
 261         ret = bgpio_init(gc, dev, 4,
 262                         gs->gpio_io + YU_GPIO_DATAIN,
 263                         gs->gpio_io + YU_GPIO_DATASET,
 264                         gs->gpio_io + YU_GPIO_DATACLEAR,
 265                         NULL,
 266                         NULL,
 267                         0);
 268
 269         gc->direction_input = mlxbf2_gpio_direction_input;
 270         gc->direction_output = mlxbf2_gpio_direction_output;
 271         gc->ngpio = npins;
 272         gc->owner = THIS_MODULE;
 273
 274         platform_set_drvdata(pdev, gs);
 275
 276         ret = devm_gpiochip_add_data(dev, &gs->gc, gs);
 277         if (ret) {
 278                 dev_err(dev, "Failed adding memory mapped gpiochip\n");
 279                 return ret;
 280         }
 281
 282         return 0;
 283 }
 284
 285 #ifdef CONFIG_PM
 286 static int mlxbf2_gpio_suspend(struct platform_device *pdev,
 287                                 pm_message_t state)
 288 {
 289         struct mlxbf2_gpio_context *gs = platform_get_drvdata(pdev);
 290
 291         gs->csave_regs->gpio_mode0 = readl(gs->gpio_io +
 292                 YU_GPIO_MODE0);
 293         gs->csave_regs->gpio_mode1 = readl(gs->gpio_io +
 294                 YU_GPIO_MODE1);
 295
 296         return 0;
 297 }
 298
 299 static int mlxbf2_gpio_resume(struct platform_device *pdev)
 300 {
 301         struct mlxbf2_gpio_context *gs = platform_get_drvdata(pdev);
 302
 303         writel(gs->csave_regs->gpio_mode0, gs->gpio_io +
 304                 YU_GPIO_MODE0);
 305         writel(gs->csave_regs->gpio_mode1, gs->gpio_io +
 306                 YU_GPIO_MODE1);
 307
 308         return 0;
 309 }
 310 #endif
 311
 312 static const struct acpi_device_id mlxbf2_gpio_acpi_match[] = {
 313         { "MLNXBF22", 0 },
 314         {},
 315 };
 316 MODULE_DEVICE_TABLE(acpi, mlxbf2_gpio_acpi_match);
 317
 318 static struct platform_driver mlxbf2_gpio_driver = {
 319         .driver = {
 320                 .name = "mlxbf2_gpio",
 321                 .acpi_match_table = ACPI_PTR(mlxbf2_gpio_acpi_match),
 322         },
 323         .probe    = mlxbf2_gpio_probe,
 324 #ifdef CONFIG_PM
 325         .suspend  = mlxbf2_gpio_suspend,
 326         .resume   = mlxbf2_gpio_resume,
 327 #endif
 328 };
 329
 330 module_platform_driver(mlxbf2_gpio_driver);
 331
 332 MODULE_DESCRIPTION("Mellanox BlueField-2 GPIO Driver");
 333 MODULE_AUTHOR("Mellanox Technologies");
 334 MODULE_LICENSE("GPL v2");