1 files changed, 530 insertions, 0 deletions

diff --git a/drivers/gpu/drm/zte/zx_vga.c b/drivers/gpu/drm/zte/zx_vga.c
new file mode 100644
index 000000000..23d1ff435
--- /dev/null
+++ b/drivers/gpu/drm/zte/zx_vga.c
@@ -0,0 +1,530 @@
+/*
+ * Copyright (C) 2017 Sanechips Technology Co., Ltd.
+ * Copyright 2017 Linaro Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/component.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drmP.h>
+
+#include "zx_drm_drv.h"
+#include "zx_vga_regs.h"
+#include "zx_vou.h"
+
+struct zx_vga_pwrctrl {
+	struct regmap *regmap;
+	u32 reg;
+	u32 mask;
+};
+
+struct zx_vga_i2c {
+	struct i2c_adapter adap;
+	struct mutex lock;
+};
+
+struct zx_vga {
+	struct drm_connector connector;
+	struct drm_encoder encoder;
+	struct zx_vga_i2c *ddc;
+	struct device *dev;
+	void __iomem *mmio;
+	struct clk *i2c_wclk;
+	struct zx_vga_pwrctrl pwrctrl;
+	struct completion complete;
+	bool connected;
+};
+
+#define to_zx_vga(x) container_of(x, struct zx_vga, x)
+
+static void zx_vga_encoder_enable(struct drm_encoder *encoder)
+{
+	struct zx_vga *vga = to_zx_vga(encoder);
+	struct zx_vga_pwrctrl *pwrctrl = &vga->pwrctrl;
+
+	/* Set bit to power up VGA DACs */
+	regmap_update_bits(pwrctrl->regmap, pwrctrl->reg, pwrctrl->mask,
+			   pwrctrl->mask);
+
+	vou_inf_enable(VOU_VGA, encoder->crtc);
+}
+
+static void zx_vga_encoder_disable(struct drm_encoder *encoder)
+{
+	struct zx_vga *vga = to_zx_vga(encoder);
+	struct zx_vga_pwrctrl *pwrctrl = &vga->pwrctrl;
+
+	vou_inf_disable(VOU_VGA, encoder->crtc);
+
+	/* Clear bit to power down VGA DACs */
+	regmap_update_bits(pwrctrl->regmap, pwrctrl->reg, pwrctrl->mask, 0);
+}
+
+static const struct drm_encoder_helper_funcs zx_vga_encoder_helper_funcs = {
+	.enable	= zx_vga_encoder_enable,
+	.disable = zx_vga_encoder_disable,
+};
+
+static const struct drm_encoder_funcs zx_vga_encoder_funcs = {
+	.destroy = drm_encoder_cleanup,
+};
+
+static int zx_vga_connector_get_modes(struct drm_connector *connector)
+{
+	struct zx_vga *vga = to_zx_vga(connector);
+	struct edid *edid;
+	int ret;
+
+	/*
+	 * Clear both detection bits to switch I2C bus from device
+	 * detecting to EDID reading.
+	 */
+	zx_writel(vga->mmio + VGA_AUTO_DETECT_SEL, 0);
+
+	edid = drm_get_edid(connector, &vga->ddc->adap);
+	if (!edid) {
+		/*
+		 * If EDID reading fails, we set the device state into
+		 * disconnected.  Locking is not required here, since the
+		 * VGA_AUTO_DETECT_SEL register write in irq handler cannot
+		 * be triggered when both detection bits are cleared as above.
+		 */
+		zx_writel(vga->mmio + VGA_AUTO_DETECT_SEL,
+			  VGA_DETECT_SEL_NO_DEVICE);
+		vga->connected = false;
+		return 0;
+	}
+
+	/*
+	 * As edid reading succeeds, device must be connected, so we set
+	 * up detection bit for unplug interrupt here.
+	 */
+	zx_writel(vga->mmio + VGA_AUTO_DETECT_SEL, VGA_DETECT_SEL_HAS_DEVICE);
+
+	drm_connector_update_edid_property(connector, edid);
+	ret = drm_add_edid_modes(connector, edid);
+	kfree(edid);
+
+	return ret;
+}
+
+static enum drm_mode_status
+zx_vga_connector_mode_valid(struct drm_connector *connector,
+			    struct drm_display_mode *mode)
+{
+	return MODE_OK;
+}
+
+static struct drm_connector_helper_funcs zx_vga_connector_helper_funcs = {
+	.get_modes = zx_vga_connector_get_modes,
+	.mode_valid = zx_vga_connector_mode_valid,
+};
+
+static enum drm_connector_status
+zx_vga_connector_detect(struct drm_connector *connector, bool force)
+{
+	struct zx_vga *vga = to_zx_vga(connector);
+
+	return vga->connected ? connector_status_connected :
+				connector_status_disconnected;
+}
+
+static const struct drm_connector_funcs zx_vga_connector_funcs = {
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.detect = zx_vga_connector_detect,
+	.destroy = drm_connector_cleanup,
+	.reset = drm_atomic_helper_connector_reset,
+	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static int zx_vga_register(struct drm_device *drm, struct zx_vga *vga)
+{
+	struct drm_encoder *encoder = &vga->encoder;
+	struct drm_connector *connector = &vga->connector;
+	struct device *dev = vga->dev;
+	int ret;
+
+	encoder->possible_crtcs = VOU_CRTC_MASK;
+
+	ret = drm_encoder_init(drm, encoder, &zx_vga_encoder_funcs,
+			       DRM_MODE_ENCODER_DAC, NULL);
+	if (ret) {
+		DRM_DEV_ERROR(dev, "failed to init encoder: %d\n", ret);
+		return ret;
+	};
+
+	drm_encoder_helper_add(encoder, &zx_vga_encoder_helper_funcs);
+
+	vga->connector.polled = DRM_CONNECTOR_POLL_HPD;
+
+	ret = drm_connector_init(drm, connector, &zx_vga_connector_funcs,
+				 DRM_MODE_CONNECTOR_VGA);
+	if (ret) {
+		DRM_DEV_ERROR(dev, "failed to init connector: %d\n", ret);
+		goto clean_encoder;
+	};
+
+	drm_connector_helper_add(connector, &zx_vga_connector_helper_funcs);
+
+	ret = drm_connector_attach_encoder(connector, encoder);
+	if (ret) {
+		DRM_DEV_ERROR(dev, "failed to attach encoder: %d\n", ret);
+		goto clean_connector;
+	};
+
+	return 0;
+
+clean_connector:
+	drm_connector_cleanup(connector);
+clean_encoder:
+	drm_encoder_cleanup(encoder);
+	return ret;
+}
+
+static int zx_vga_pwrctrl_init(struct zx_vga *vga)
+{
+	struct zx_vga_pwrctrl *pwrctrl = &vga->pwrctrl;
+	struct device *dev = vga->dev;
+	struct of_phandle_args out_args;
+	struct regmap *regmap;
+	int ret;
+
+	ret = of_parse_phandle_with_fixed_args(dev->of_node,
+				"zte,vga-power-control", 2, 0, &out_args);
+	if (ret)
+		return ret;
+
+	regmap = syscon_node_to_regmap(out_args.np);
+	if (IS_ERR(regmap)) {
+		ret = PTR_ERR(regmap);
+		goto out;
+	}
+
+	pwrctrl->regmap = regmap;
+	pwrctrl->reg = out_args.args[0];
+	pwrctrl->mask = out_args.args[1];
+
+out:
+	of_node_put(out_args.np);
+	return ret;
+}
+
+static int zx_vga_i2c_read(struct zx_vga *vga, struct i2c_msg *msg)
+{
+	int len = msg->len;
+	u8 *buf = msg->buf;
+	u32 offset = 0;
+	int i;
+
+	reinit_completion(&vga->complete);
+
+	/* Select combo write */
+	zx_writel_mask(vga->mmio + VGA_CMD_CFG, VGA_CMD_COMBO, VGA_CMD_COMBO);
+	zx_writel_mask(vga->mmio + VGA_CMD_CFG, VGA_CMD_RW, 0);
+
+	while (len > 0) {
+		u32 cnt;
+
+		/* Clear RX FIFO */
+		zx_writel_mask(vga->mmio + VGA_RXF_CTRL, VGA_RX_FIFO_CLEAR,
+			       VGA_RX_FIFO_CLEAR);
+
+		/* Data offset to read from */
+		zx_writel(vga->mmio + VGA_SUB_ADDR, offset);
+
+		/* Kick off the transfer */
+		zx_writel_mask(vga->mmio + VGA_CMD_CFG, VGA_CMD_TRANS,
+			       VGA_CMD_TRANS);
+
+		if (!wait_for_completion_timeout(&vga->complete,
+						 msecs_to_jiffies(1000))) {
+			DRM_DEV_ERROR(vga->dev, "transfer timeout\n");
+			return -ETIMEDOUT;
+		}
+
+		cnt = zx_readl(vga->mmio + VGA_RXF_STATUS);
+		cnt = (cnt & VGA_RXF_COUNT_MASK) >> VGA_RXF_COUNT_SHIFT;
+		/* FIFO status may report more data than we need to read */
+		cnt = min_t(u32, len, cnt);
+
+		for (i = 0; i < cnt; i++)
+			*buf++ = zx_readl(vga->mmio + VGA_DATA);
+
+		len -= cnt;
+		offset += cnt;
+	}
+
+	return 0;
+}
+
+static int zx_vga_i2c_write(struct zx_vga *vga, struct i2c_msg *msg)
+{
+	/*
+	 * The DDC I2C adapter is only for reading EDID data, so we assume
+	 * that the write to this adapter must be the EDID data offset.
+	 */
+	if ((msg->len != 1) || ((msg->addr != DDC_ADDR)))
+		return -EINVAL;
+
+	/* Hardware will take care of the slave address shifting */
+	zx_writel(vga->mmio + VGA_DEVICE_ADDR, msg->addr);
+
+	return 0;
+}
+
+static int zx_vga_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+			   int num)
+{
+	struct zx_vga *vga = i2c_get_adapdata(adap);
+	struct zx_vga_i2c *ddc = vga->ddc;
+	int ret = 0;
+	int i;
+
+	mutex_lock(&ddc->lock);
+
+	for (i = 0; i < num; i++) {
+		if (msgs[i].flags & I2C_M_RD)
+			ret = zx_vga_i2c_read(vga, &msgs[i]);
+		else
+			ret = zx_vga_i2c_write(vga, &msgs[i]);
+
+		if (ret < 0)
+			break;
+	}
+
+	if (!ret)
+		ret = num;
+
+	mutex_unlock(&ddc->lock);
+
+	return ret;
+}
+
+static u32 zx_vga_i2c_func(struct i2c_adapter *adapter)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm zx_vga_algorithm = {
+	.master_xfer	= zx_vga_i2c_xfer,
+	.functionality	= zx_vga_i2c_func,
+};
+
+static int zx_vga_ddc_register(struct zx_vga *vga)
+{
+	struct device *dev = vga->dev;
+	struct i2c_adapter *adap;
+	struct zx_vga_i2c *ddc;
+	int ret;
+
+	ddc = devm_kzalloc(dev, sizeof(*ddc), GFP_KERNEL);
+	if (!ddc)
+		return -ENOMEM;
+
+	vga->ddc = ddc;
+	mutex_init(&ddc->lock);
+
+	adap = &ddc->adap;
+	adap->owner = THIS_MODULE;
+	adap->class = I2C_CLASS_DDC;
+	adap->dev.parent = dev;
+	adap->algo = &zx_vga_algorithm;
+	snprintf(adap->name, sizeof(adap->name), "zx vga i2c");
+
+	ret = i2c_add_adapter(adap);
+	if (ret) {
+		DRM_DEV_ERROR(dev, "failed to add I2C adapter: %d\n", ret);
+		return ret;
+	}
+
+	i2c_set_adapdata(adap, vga);
+
+	return 0;
+}
+
+static irqreturn_t zx_vga_irq_thread(int irq, void *dev_id)
+{
+	struct zx_vga *vga = dev_id;
+
+	drm_helper_hpd_irq_event(vga->connector.dev);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t zx_vga_irq_handler(int irq, void *dev_id)
+{
+	struct zx_vga *vga = dev_id;
+	u32 status;
+
+	status = zx_readl(vga->mmio + VGA_I2C_STATUS);
+
+	/* Clear interrupt status */
+	zx_writel_mask(vga->mmio + VGA_I2C_STATUS, VGA_CLEAR_IRQ,
+		       VGA_CLEAR_IRQ);
+
+	if (status & VGA_DEVICE_CONNECTED) {
+		/*
+		 * Since VGA_DETECT_SEL bits need to be reset for switching DDC
+		 * bus from device detection to EDID read, rather than setting
+		 * up HAS_DEVICE bit here, we need to do that in .get_modes
+		 * hook for unplug detecting after EDID read succeeds.
+		 */
+		vga->connected = true;
+		return IRQ_WAKE_THREAD;
+	}
+
+	if (status & VGA_DEVICE_DISCONNECTED) {
+		zx_writel(vga->mmio + VGA_AUTO_DETECT_SEL,
+			  VGA_DETECT_SEL_NO_DEVICE);
+		vga->connected = false;
+		return IRQ_WAKE_THREAD;
+	}
+
+	if (status & VGA_TRANS_DONE) {
+		complete(&vga->complete);
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
+static void zx_vga_hw_init(struct zx_vga *vga)
+{
+	unsigned long ref = clk_get_rate(vga->i2c_wclk);
+	int div;
+
+	/*
+	 * Set up I2C fast speed divider per formula below to get 400kHz.
+	 *   scl = ref / ((div + 1) * 4)
+	 */
+	div = DIV_ROUND_UP(ref / 1000, 400 * 4) - 1;
+	zx_writel(vga->mmio + VGA_CLK_DIV_FS, div);
+
+	/* Set up device detection */
+	zx_writel(vga->mmio + VGA_AUTO_DETECT_PARA, 0x80);
+	zx_writel(vga->mmio + VGA_AUTO_DETECT_SEL, VGA_DETECT_SEL_NO_DEVICE);
+
+	/*
+	 * We need to poke monitor via DDC bus to get connection irq
+	 * start working.
+	 */
+	zx_writel(vga->mmio + VGA_DEVICE_ADDR, DDC_ADDR);
+	zx_writel_mask(vga->mmio + VGA_CMD_CFG, VGA_CMD_TRANS, VGA_CMD_TRANS);
+}
+
+static int zx_vga_bind(struct device *dev, struct device *master, void *data)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct drm_device *drm = data;
+	struct resource *res;
+	struct zx_vga *vga;
+	int irq;
+	int ret;
+
+	vga = devm_kzalloc(dev, sizeof(*vga), GFP_KERNEL);
+	if (!vga)
+		return -ENOMEM;
+
+	vga->dev = dev;
+	dev_set_drvdata(dev, vga);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	vga->mmio = devm_ioremap_resource(dev, res);
+	if (IS_ERR(vga->mmio))
+		return PTR_ERR(vga->mmio);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	vga->i2c_wclk = devm_clk_get(dev, "i2c_wclk");
+	if (IS_ERR(vga->i2c_wclk)) {
+		ret = PTR_ERR(vga->i2c_wclk);
+		DRM_DEV_ERROR(dev, "failed to get i2c_wclk: %d\n", ret);
+		return ret;
+	}
+
+	ret = zx_vga_pwrctrl_init(vga);
+	if (ret) {
+		DRM_DEV_ERROR(dev, "failed to init power control: %d\n", ret);
+		return ret;
+	}
+
+	ret = zx_vga_ddc_register(vga);
+	if (ret) {
+		DRM_DEV_ERROR(dev, "failed to register ddc: %d\n", ret);
+		return ret;
+	}
+
+	ret = zx_vga_register(drm, vga);
+	if (ret) {
+		DRM_DEV_ERROR(dev, "failed to register vga: %d\n", ret);
+		return ret;
+	}
+
+	init_completion(&vga->complete);
+
+	ret = devm_request_threaded_irq(dev, irq, zx_vga_irq_handler,
+					zx_vga_irq_thread, IRQF_SHARED,
+					dev_name(dev), vga);
+	if (ret) {
+		DRM_DEV_ERROR(dev, "failed to request threaded irq: %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(vga->i2c_wclk);
+	if (ret)
+		return ret;
+
+	zx_vga_hw_init(vga);
+
+	return 0;
+}
+
+static void zx_vga_unbind(struct device *dev, struct device *master,
+			  void *data)
+{
+	struct zx_vga *vga = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(vga->i2c_wclk);
+}
+
+static const struct component_ops zx_vga_component_ops = {
+	.bind = zx_vga_bind,
+	.unbind = zx_vga_unbind,
+};
+
+static int zx_vga_probe(struct platform_device *pdev)
+{
+	return component_add(&pdev->dev, &zx_vga_component_ops);
+}
+
+static int zx_vga_remove(struct platform_device *pdev)
+{
+	component_del(&pdev->dev, &zx_vga_component_ops);
+	return 0;
+}
+
+static const struct of_device_id zx_vga_of_match[] = {
+	{ .compatible = "zte,zx296718-vga", },
+	{ /* end */ },
+};
+MODULE_DEVICE_TABLE(of, zx_vga_of_match);
+
+struct platform_driver zx_vga_driver = {
+	.probe = zx_vga_probe,
+	.remove = zx_vga_remove,
+	.driver	= {
+		.name = "zx-vga",
+		.of_match_table	= zx_vga_of_match,
+	},
+};