drm/nouveau: implement a simple sysfs interface to new pm code

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/Makefile

@@ -300,7 +300,7 @@ include $(src)/dispnv04/Makefile
 nouveau-y += nv50_display.o
 
 # drm/pm
-nouveau-y += nouveau_hwmon.o
+nouveau-y += nouveau_hwmon.o nouveau_sysfs.o
 
 # other random bits
 nouveau-$(CONFIG_COMPAT) += nouveau_ioc32.o

drivers/gpu/drm/nouveau/nouveau_drm.c

@@ -46,6 +46,7 @@
 #include "nouveau_gem.h"
 #include "nouveau_agp.h"
 #include "nouveau_vga.h"
+#include "nouveau_sysfs.h"
 #include "nouveau_hwmon.h"
 #include "nouveau_acpi.h"
 #include "nouveau_bios.h"
@@ -384,6 +385,7 @@ nouveau_drm_load(struct drm_device *dev, unsigned long flags)
 			goto fail_dispinit;
 	}
 
+	nouveau_sysfs_init(dev);
 	nouveau_hwmon_init(dev);
 	nouveau_accel_init(drm);
 	nouveau_fbcon_init(dev);
@@ -421,6 +423,7 @@ nouveau_drm_unload(struct drm_device *dev)
 	nouveau_fbcon_fini(dev);
 	nouveau_accel_fini(drm);
 	nouveau_hwmon_fini(dev);
+	nouveau_sysfs_fini(dev);
 
 	if (dev->mode_config.num_crtc)
 		nouveau_display_fini(dev);

drivers/gpu/drm/nouveau/nouveau_drm.h

@@ -53,6 +53,7 @@ struct nouveau_drm_tile {
 enum nouveau_drm_handle {
 	NVDRM_CLIENT  = 0xffffffff,
 	NVDRM_DEVICE  = 0xdddddddd,
+	NVDRM_CONTROL = 0xdddddddc,
 	NVDRM_PUSH    = 0xbbbb0000, /* |= client chid */
 	NVDRM_CHAN    = 0xcccc0000, /* |= client chid */
 };
@@ -130,6 +131,7 @@ struct nouveau_drm {
 
 	/* power management */
 	struct nouveau_hwmon *hwmon;
+	struct nouveau_sysfs *sysfs;
 
 	/* display power reference */
 	bool have_disp_power_ref;

drivers/gpu/drm/nouveau/nouveau_sysfs.c

@@ -0,0 +1,162 @@
+/*
+ * Copyright 2013 Red Hat Inc.
+ *
+ * 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: Ben Skeggs <bskeggs@redhat.com>
+ */
+
+#include "nouveau_sysfs.h"
+
+#include <core/object.h>
+#include <core/class.h>
+
+static inline struct drm_device *
+drm_device(struct device *d)
+{
+	return pci_get_drvdata(to_pci_dev(d));
+}
+
+#define snappendf(p,r,f,a...) do {                                             \
+	snprintf(p, r, f, ##a);                                                \
+	r -= strlen(p);                                                        \
+	p += strlen(p);                                                        \
+} while(0)
+
+static ssize_t
+nouveau_sysfs_pstate_get(struct device *d, struct device_attribute *a, char *b)
+{
+	struct nouveau_sysfs *sysfs = nouveau_sysfs(drm_device(d));
+	struct nv_control_pstate_info info;
+	size_t cnt = PAGE_SIZE;
+	char *buf = b;
+	int ret, i;
+
+	ret = nv_exec(sysfs->ctrl, NV_CONTROL_PSTATE_INFO, &info, sizeof(info));
+	if (ret)
+		return ret;
+
+	for (i = 0; i < info.count + 1; i++) {
+		const s32 state = i < info.count ? i :
+			NV_CONTROL_PSTATE_ATTR_STATE_CURRENT;
+		struct nv_control_pstate_attr attr = {
+			.state = state,
+			.index = 0,
+		};
+
+		ret = nv_exec(sysfs->ctrl, NV_CONTROL_PSTATE_ATTR,
+			     &attr, sizeof(attr));
+		if (ret)
+			return ret;
+
+		if (i < info.count)
+			snappendf(buf, cnt, "%02x:", attr.state);
+		else
+			snappendf(buf, cnt, "--:");
+
+		attr.index = 0;
+		do {
+			attr.state = state;
+			ret = nv_exec(sysfs->ctrl, NV_CONTROL_PSTATE_ATTR,
+				     &attr, sizeof(attr));
+			if (ret)
+				return ret;
+
+			snappendf(buf, cnt, " %s %d", attr.name, attr.min);
+			if (attr.min != attr.max)
+				snappendf(buf, cnt, "-%d", attr.max);
+			snappendf(buf, cnt, " %s", attr.unit);
+		} while (attr.index);
+
+		if ((state >= 0 && info.pstate == state) ||
+		    (state <  0 && info.ustate < 0))
+			snappendf(buf, cnt, " *");
+		snappendf(buf, cnt, "\n");
+	}
+
+	return strlen(b);
+}
+
+static ssize_t
+nouveau_sysfs_pstate_set(struct device *d, struct device_attribute *a,
+			 const char *buf, size_t count)
+{
+	struct nouveau_sysfs *sysfs = nouveau_sysfs(drm_device(d));
+	struct nv_control_pstate_user args;
+	long value, ret;
+	char *tmp;
+
+	if ((tmp = strchr(buf, '\n')))
+		*tmp = '\0';
+
+	if (!strcasecmp(buf, "none"))
+		args.state = NV_CONTROL_PSTATE_USER_STATE_UNKNOWN;
+	else
+	if (!strcasecmp(buf, "auto"))
+		args.state = NV_CONTROL_PSTATE_USER_STATE_PERFMON;
+	else {
+		ret = kstrtol(buf, 16, &value);
+		if (ret)
+			return ret;
+		args.state = value;
+	}
+
+	ret = nv_exec(sysfs->ctrl, NV_CONTROL_PSTATE_USER, &args, sizeof(args));
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR(pstate, S_IRUGO | S_IWUSR,
+		   nouveau_sysfs_pstate_get, nouveau_sysfs_pstate_set);
+
+void
+nouveau_sysfs_fini(struct drm_device *dev)
+{
+	struct nouveau_sysfs *sysfs = nouveau_sysfs(dev);
+	struct nouveau_drm *drm = nouveau_drm(dev);
+
+	if (sysfs->ctrl) {
+		device_remove_file(&dev->pdev->dev, &dev_attr_pstate);
+		nouveau_object_del(nv_object(drm), NVDRM_DEVICE, NVDRM_CONTROL);
+	}
+
+	drm->sysfs = NULL;
+	kfree(sysfs);
+}
+
+int
+nouveau_sysfs_init(struct drm_device *dev)
+{
+	struct nouveau_drm *drm = nouveau_drm(dev);
+	struct nouveau_sysfs *sysfs;
+	int ret;
+
+	sysfs = drm->sysfs = kzalloc(sizeof(*sysfs), GFP_KERNEL);
+	if (!sysfs)
+		return -ENOMEM;
+
+	ret = nouveau_object_new(nv_object(drm), NVDRM_DEVICE, NVDRM_CONTROL,
+				 NV_CONTROL_CLASS, NULL, 0, &sysfs->ctrl);
+	if (ret == 0)
+		device_create_file(&dev->pdev->dev, &dev_attr_pstate);
+
+	return 0;
+}

drivers/gpu/drm/nouveau/nouveau_sysfs.h

@@ -0,0 +1,19 @@
+#ifndef __NOUVEAU_SYSFS_H__
+#define __NOUVEAU_SYSFS_H__
+
+#include "nouveau_drm.h"
+
+struct nouveau_sysfs {
+	struct nouveau_object *ctrl;
+};
+
+static inline struct nouveau_sysfs *
+nouveau_sysfs(struct drm_device *dev)
+{
+	return nouveau_drm(dev)->sysfs;
+}
+
+int  nouveau_sysfs_init(struct drm_device *);
+void nouveau_sysfs_fini(struct drm_device *);
+
+#endif