text: /*
   * Copyright 2015 Martin Peres
   *
   * Permission is hereby granted, free of charge, to any person obtaining a
   * copy of this software and associated documentation files (the "Software"),
   * to deal in the Software without restriction, including without limitation
   * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   * and/or sell copies of the Software, and to permit persons to whom the
   * Software is furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
   * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
   * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
   * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
   * OTHER DEALINGS IN THE SOFTWARE.
   *
   * Authors: Martin Peres
   */
  #include "priv.h"
  
  #include <subdev/volt.h>
  #include <subdev/gpio.h>
  #include <subdev/bios.h>
  #include <subdev/bios/volt.h>
  #include <subdev/fuse.h>
  
  #define gk104_volt(p) container_of((p), struct gk104_volt, base)
  struct gk104_volt {
  	struct nvkm_volt base;
  	struct nvbios_volt bios;
  };
  
  static int
  gk104_volt_get(struct nvkm_volt *base)
  {
  	struct nvbios_volt *bios = &gk104_volt(base)->bios;
  	struct nvkm_device *device = base->subdev.device;
  	u32 div, duty;
  
  	div  = nvkm_rd32(device, 0x20340);
  	duty = nvkm_rd32(device, 0x20344);
  
  	return bios->base + bios->pwm_range * duty / div;
  }
  
  static int
  gk104_volt_set(struct nvkm_volt *base, u32 uv)
  {
  	struct nvbios_volt *bios = &gk104_volt(base)->bios;
  	struct nvkm_device *device = base->subdev.device;
  	u32 div, duty;
  
  	/* the blob uses this crystal frequency, let's use it too. */
  	div = 27648000 / bios->pwm_freq;
  	duty = DIV_ROUND_UP((uv - bios->base) * div, bios->pwm_range);
  
  	nvkm_wr32(device, 0x20340, div);
  	nvkm_wr32(device, 0x20344, 0x80000000 | duty);
  
  	return 0;
  }
  
  static int
  gk104_volt_speedo_read(struct nvkm_volt *volt)
  {
  	struct nvkm_device *device = volt->subdev.device;
  	struct nvkm_fuse *fuse = device->fuse;
  	int ret;
  
  	if (!fuse)
  		return -EINVAL;
  
  	nvkm_wr32(device, 0x122634, 0x0);
  	ret = nvkm_fuse_read(fuse, 0x3a8);
  	nvkm_wr32(device, 0x122634, 0x41);
  	return ret;
  }
  
  static const struct nvkm_volt_func
  gk104_volt_pwm = {
  	.oneinit = gf100_volt_oneinit,
  	.volt_get = gk104_volt_get,
  	.volt_set = gk104_volt_set,
  	.speedo_read = gk104_volt_speedo_read,
  }, gk104_volt_gpio = {
  	.oneinit = gf100_volt_oneinit,
  	.vid_get = nvkm_voltgpio_get,
  	.vid_set = nvkm_voltgpio_set,
  	.speedo_read = gk104_volt_speedo_read,
  };
  
  int
  gk104_volt_new(struct nvkm_device *device, enum nvkm_subdev_type type, int inst,
  	       struct nvkm_volt **pvolt)
  {
  	const struct nvkm_volt_func *volt_func = &gk104_volt_gpio;
  	struct dcb_gpio_func gpio;
  	struct nvbios_volt bios;
  	struct gk104_volt *volt;
  	u8 ver, hdr, cnt, len;
  	const char *mode;
  
  	if (!nvbios_volt_parse(device->bios, &ver, &hdr, &cnt, &len, &bios))
  		return 0;
  
  	if (!nvkm_gpio_find(device->gpio, 0, DCB_GPIO_VID_PWM, 0xff, &gpio) &&
  	    bios.type == NVBIOS_VOLT_PWM) {
  		volt_func = &gk104_volt_pwm;
  	}
  
  	if (!(volt = kzalloc(sizeof(*volt), GFP_KERNEL)))
  		return -ENOMEM;
  	nvkm_volt_ctor(volt_func, device, type, inst, &volt->base);
  	*pvolt = &volt->base;
  	volt->bios = bios;
  
  	/* now that we have a subdev, we can show an error if we found through
  	 * the voltage table that we were supposed to use the PWN mode but we
  	 * did not find the right GPIO for it.
  	 */
  	if (bios.type == NVBIOS_VOLT_PWM && volt_func != &gk104_volt_pwm) {
  		nvkm_error(&volt->base.subdev,
  			   "Type mismatch between the voltage table type and "
  			   "the GPIO table. Fallback to GPIO mode.\n");
  	}
  
  	if (volt_func == &gk104_volt_gpio) {
  		nvkm_voltgpio_init(&volt->base);
  		mode = "GPIO";
  	} else
  		mode = "PWM";
  
  	nvkm_debug(&volt->base.subdev, "Using %s mode\n", mode);
  
  	return 0;
  }
  