drm/nouveau: support for probing platform devices

Add a platform driver for Nouveau devices declared using the device tree
or platform data. This driver currently supports GK20A on Tegra
platforms and is only compiled for these platforms if Nouveau is
enabled.

Nouveau will probe the chip type itself using the BOOT0 register, so all
this driver really needs to do is to make sure the module is powered and
its clocks active before calling nouveau_drm_platform_probe().

Heavily based on work done by Thierry Reding.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 182 insertions, 0 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_platform.c b/drivers/gpu/drm/nouveau/nouveau_platform.c
new file mode 100644
index 000000000000..72ab0519abf6
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/nouveau_platform.c
@@ -0,0 +1,182 @@
+/*
+ * Copyright (c) 2014, NVIDIA CORPORATION. All rights reserved.
+ *
+ * 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 AUTHORS OR COPYRIGHT HOLDERS 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.
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/reset.h>
+#include <linux/regulator/consumer.h>
+#include <linux/tegra-powergate.h>
+
+#include "nouveau_drm.h"
+#include "nouveau_platform.h"
+
+static int nouveau_platform_power_up(struct nouveau_platform_gpu *gpu)
+{
+	int err;
+
+	err = regulator_enable(gpu->vdd);
+	if (err)
+		goto err_power;
+
+	err = clk_prepare_enable(gpu->clk);
+	if (err)
+		goto err_clk;
+	err = clk_prepare_enable(gpu->clk_pwr);
+	if (err)
+		goto err_clk_pwr;
+	clk_set_rate(gpu->clk_pwr, 204000000);
+	udelay(10);
+
+	reset_control_assert(gpu->rst);
+	udelay(10);
+
+	err = tegra_powergate_remove_clamping(TEGRA_POWERGATE_3D);
+	if (err)
+		goto err_clamp;
+	udelay(10);
+
+	reset_control_deassert(gpu->rst);
+	udelay(10);
+
+	return 0;
+
+err_clamp:
+	clk_disable_unprepare(gpu->clk_pwr);
+err_clk_pwr:
+	clk_disable_unprepare(gpu->clk);
+err_clk:
+	regulator_disable(gpu->vdd);
+err_power:
+	return err;
+}
+
+static int nouveau_platform_power_down(struct nouveau_platform_gpu *gpu)
+{
+	int err;
+
+	reset_control_assert(gpu->rst);
+	udelay(10);
+
+	clk_disable_unprepare(gpu->clk_pwr);
+	clk_disable_unprepare(gpu->clk);
+	udelay(10);
+
+	err = regulator_disable(gpu->vdd);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static int nouveau_platform_probe(struct platform_device *pdev)
+{
+	struct nouveau_platform_gpu *gpu;
+	struct nouveau_platform_device *device;
+	struct drm_device *drm;
+	int err;
+
+	gpu = devm_kzalloc(&pdev->dev, sizeof(*gpu), GFP_KERNEL);
+	if (!gpu)
+		return -ENOMEM;
+
+	gpu->vdd = devm_regulator_get(&pdev->dev, "vdd");
+	if (IS_ERR(gpu->vdd))
+		return PTR_ERR(gpu->vdd);
+
+	gpu->rst = devm_reset_control_get(&pdev->dev, "gpu");
+	if (IS_ERR(gpu->rst))
+		return PTR_ERR(gpu->rst);
+
+	gpu->clk = devm_clk_get(&pdev->dev, "gpu");
+	if (IS_ERR(gpu->clk))
+		return PTR_ERR(gpu->clk);
+
+	gpu->clk_pwr = devm_clk_get(&pdev->dev, "pwr");
+	if (IS_ERR(gpu->clk_pwr))
+		return PTR_ERR(gpu->clk_pwr);
+
+	err = nouveau_platform_power_up(gpu);
+	if (err)
+		return err;
+
+	drm = nouveau_platform_device_create(pdev, &device);
+	if (IS_ERR(drm)) {
+		err = PTR_ERR(drm);
+		goto power_down;
+	}
+
+	device->gpu = gpu;
+
+	err = drm_dev_register(drm, 0);
+	if (err < 0)
+		goto err_unref;
+
+	return 0;
+
+err_unref:
+	drm_dev_unref(drm);
+
+	return 0;
+
+power_down:
+	nouveau_platform_power_down(gpu);
+
+	return err;
+}
+
+static int nouveau_platform_remove(struct platform_device *pdev)
+{
+	struct drm_device *drm_dev = platform_get_drvdata(pdev);
+	struct nouveau_device *device = nouveau_dev(drm_dev);
+	struct nouveau_platform_gpu *gpu = nv_device_to_platform(device)->gpu;
+
+	nouveau_drm_device_remove(drm_dev);
+
+	return nouveau_platform_power_down(gpu);
+}
+
+#if IS_ENABLED(CONFIG_OF)
+static const struct of_device_id nouveau_platform_match[] = {
+	{ .compatible = "nvidia,gk20a" },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(of, nouveau_platform_match);
+#endif
+
+struct platform_driver nouveau_platform_driver = {
+	.driver = {
+		.name = "nouveau",
+		.of_match_table = of_match_ptr(nouveau_platform_match),
+	},
+	.probe = nouveau_platform_probe,
+	.remove = nouveau_platform_remove,
+};
+
+module_platform_driver(nouveau_platform_driver);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL and additional rights");