drm/nouveau/volt/gk104: add support for pwm and gpio modes

Most Keplers actually use the GPIO-based voltage management instead of the new
PWM-based one. Use the GPIO mode as a fallback as it already gracefully handles
the case where no GPIOs exist.

All the Maxwells seem to use the PWM method though.

v2:
 - Do not forget to commit the PWM configuration change!
Signed-off-by: Martin Peres <martin.peres@free.fr>

drivers/gpu/drm/nouveau/include/nvkm/subdev/bios/gpio.h

@@ -15,6 +15,7 @@ enum dcb_gpio_func_name {
 	DCB_GPIO_VID5 = 0x74,
 	DCB_GPIO_VID6 = 0x75,
 	DCB_GPIO_VID7 = 0x76,
+	DCB_GPIO_VID_PWM = 0x81,
 };
 
 #define DCB_GPIO_LOG_DIR     0x02

drivers/gpu/drm/nouveau/include/nvkm/subdev/volt.h

@@ -18,5 +18,6 @@ int nvkm_volt_get(struct nvkm_volt *);
 int nvkm_volt_set_id(struct nvkm_volt *, u8 id, int condition);
 
 int nv40_volt_new(struct nvkm_device *, int, struct nvkm_volt **);
+int gk104_volt_new(struct nvkm_device *, int, struct nvkm_volt **);
 int gk20a_volt_new(struct nvkm_device *, int, struct nvkm_volt **);
 #endif

drivers/gpu/drm/nouveau/nvkm/engine/device/base.c

@@ -1673,7 +1673,7 @@ nve4_chipset = {
 	.pmu = gk104_pmu_new,
 	.therm = gf119_therm_new,
 	.timer = nv41_timer_new,
-	.volt = nv40_volt_new,
+	.volt = gk104_volt_new,
 	.ce[0] = gk104_ce_new,
 	.ce[1] = gk104_ce_new,
 	.ce[2] = gk104_ce_new,
@@ -1710,7 +1710,7 @@ nve6_chipset = {
 	.pmu = gk104_pmu_new,
 	.therm = gf119_therm_new,
 	.timer = nv41_timer_new,
-	.volt = nv40_volt_new,
+	.volt = gk104_volt_new,
 	.ce[0] = gk104_ce_new,
 	.ce[1] = gk104_ce_new,
 	.ce[2] = gk104_ce_new,
@@ -1747,7 +1747,7 @@ nve7_chipset = {
 	.pmu = gf119_pmu_new,
 	.therm = gf119_therm_new,
 	.timer = nv41_timer_new,
-	.volt = nv40_volt_new,
+	.volt = gk104_volt_new,
 	.ce[0] = gk104_ce_new,
 	.ce[1] = gk104_ce_new,
 	.ce[2] = gk104_ce_new,
@@ -1808,7 +1808,7 @@ nvf0_chipset = {
 	.pmu = gk110_pmu_new,
 	.therm = gf119_therm_new,
 	.timer = nv41_timer_new,
-	.volt = nv40_volt_new,
+	.volt = gk104_volt_new,
 	.ce[0] = gk104_ce_new,
 	.ce[1] = gk104_ce_new,
 	.ce[2] = gk104_ce_new,
@@ -1844,7 +1844,7 @@ nvf1_chipset = {
 	.pmu = gk110_pmu_new,
 	.therm = gf119_therm_new,
 	.timer = nv41_timer_new,
-	.volt = nv40_volt_new,
+	.volt = gk104_volt_new,
 	.ce[0] = gk104_ce_new,
 	.ce[1] = gk104_ce_new,
 	.ce[2] = gk104_ce_new,
@@ -1880,7 +1880,7 @@ nv106_chipset = {
 	.pmu = gk208_pmu_new,
 	.therm = gf119_therm_new,
 	.timer = nv41_timer_new,
-	.volt = nv40_volt_new,
+	.volt = gk104_volt_new,
 	.ce[0] = gk104_ce_new,
 	.ce[1] = gk104_ce_new,
 	.ce[2] = gk104_ce_new,
@@ -1916,7 +1916,7 @@ nv108_chipset = {
 	.pmu = gk208_pmu_new,
 	.therm = gf119_therm_new,
 	.timer = nv41_timer_new,
-	.volt = nv40_volt_new,
+	.volt = gk104_volt_new,
 	.ce[0] = gk104_ce_new,
 	.ce[1] = gk104_ce_new,
 	.ce[2] = gk104_ce_new,

drivers/gpu/drm/nouveau/nvkm/subdev/volt/Kbuild

 nvkm-y += nvkm/subdev/volt/base.o
 nvkm-y += nvkm/subdev/volt/gpio.o
 nvkm-y += nvkm/subdev/volt/nv40.o
+nvkm-y += nvkm/subdev/volt/gk104.o
 nvkm-y += nvkm/subdev/volt/gk20a.o

drivers/gpu/drm/nouveau/nvkm/subdev/volt/gk104.c

+/*
+ * 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>
+
+#define gk104_volt(p) container_of((p), struct gk104_volt, base)
+struct gk104_volt {
+	struct nvkm_volt base;
+	struct nvbios_volt bios;
+};
+
+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;
+}
+
+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 = (uv - bios->base) * div / bios->pwm_range;
+
+	nvkm_wr32(device, 0x20340, div);
+	nvkm_wr32(device, 0x20344, 0x8000000 | duty);
+
+	return 0;
+}
+
+static const struct nvkm_volt_func
+gk104_volt_pwm = {
+	.volt_get = gk104_volt_get,
+	.volt_set = gk104_volt_set,
+}, gk104_volt_gpio = {
+	.vid_get = nvkm_voltgpio_get,
+	.vid_set = nvkm_voltgpio_set,
+};
+
+int
+gk104_volt_new(struct nvkm_device *device, int index, 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, index, &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;
+}

drivers/gpu/drm/nouveau/nvkm/subdev/volt/priv.h

@@ -19,4 +19,8 @@ struct nvkm_volt_func {
 int nvkm_voltgpio_init(struct nvkm_volt *);
 int nvkm_voltgpio_get(struct nvkm_volt *);
 int nvkm_voltgpio_set(struct nvkm_volt *, u8);
+
+int nvkm_voltpwm_init(struct nvkm_volt *volt);
+int nvkm_voltpwm_get(struct nvkm_volt *volt);
+int nvkm_voltpwm_set(struct nvkm_volt *volt, u32 uv);
 #endif