drm: sti: add DVO output connector

Digital Video Out connector driver LCD panels.
Like HDMI and HDA it create bridge, encoder and connector
drm object.
Add binding description.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>

1 files changed, 551 insertions, 0 deletions

diff --git a/drivers/gpu/drm/sti/sti_dvo.c b/drivers/gpu/drm/sti/sti_dvo.c
new file mode 100644
index 000000000000..651afad21f92
--- /dev/null
+++ b/drivers/gpu/drm/sti/sti_dvo.c
@@ -0,0 +1,551 @@
+/*
+ * Copyright (C) STMicroelectronics SA 2014
+ * Author: Vincent Abriou <vincent.abriou@st.com> for STMicroelectronics.
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include <linux/clk.h>
+#include <linux/component.h>
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+#include <linux/platform_device.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_panel.h>
+
+#include "sti_awg_utils.h"
+#include "sti_mixer.h"
+
+/* DVO registers */
+#define DVO_AWG_DIGSYNC_CTRL      0x0000
+#define DVO_DOF_CFG               0x0004
+#define DVO_LUT_PROG_LOW          0x0008
+#define DVO_LUT_PROG_MID          0x000C
+#define DVO_LUT_PROG_HIGH         0x0010
+#define DVO_DIGSYNC_INSTR_I       0x0100
+
+#define DVO_AWG_CTRL_EN           BIT(0)
+#define DVO_AWG_FRAME_BASED_SYNC  BIT(2)
+
+#define DVO_DOF_EN_LOWBYTE        BIT(0)
+#define DVO_DOF_EN_MIDBYTE        BIT(1)
+#define DVO_DOF_EN_HIGHBYTE       BIT(2)
+#define DVO_DOF_EN                BIT(6)
+#define DVO_DOF_MOD_COUNT_SHIFT   8
+
+#define DVO_LUT_ZERO              0
+#define DVO_LUT_Y_G               1
+#define DVO_LUT_Y_G_DEL           2
+#define DVO_LUT_CB_B              3
+#define DVO_LUT_CB_B_DEL          4
+#define DVO_LUT_CR_R              5
+#define DVO_LUT_CR_R_DEL          6
+#define DVO_LUT_HOLD              7
+
+struct dvo_config {
+	u32 flags;
+	u32 lowbyte;
+	u32 midbyte;
+	u32 highbyte;
+	int (*awg_fwgen_fct)(
+			struct awg_code_generation_params *fw_gen_params,
+			struct awg_timing *timing);
+};
+
+static struct dvo_config rgb_24bit_de_cfg = {
+	.flags         = (0L << DVO_DOF_MOD_COUNT_SHIFT),
+	.lowbyte       = DVO_LUT_CR_R,
+	.midbyte       = DVO_LUT_Y_G,
+	.highbyte      = DVO_LUT_CB_B,
+	.awg_fwgen_fct = sti_awg_generate_code_data_enable_mode,
+};
+
+/**
+ * STI digital video output structure
+ *
+ * @dev: driver device
+ * @drm_dev: pointer to drm device
+ * @mode: current display mode selected
+ * @regs: dvo registers
+ * @clk_pix: pixel clock for dvo
+ * @clk: clock for dvo
+ * @clk_main_parent: dvo parent clock if main path used
+ * @clk_aux_parent: dvo parent clock if aux path used
+ * @panel_node: panel node reference from device tree
+ * @panel: reference to the panel connected to the dvo
+ * @enabled: true if dvo is enabled else false
+ * @encoder: drm_encoder it is bound
+ */
+struct sti_dvo {
+	struct device dev;
+	struct drm_device *drm_dev;
+	struct drm_display_mode mode;
+	void __iomem *regs;
+	struct clk *clk_pix;
+	struct clk *clk;
+	struct clk *clk_main_parent;
+	struct clk *clk_aux_parent;
+	struct device_node *panel_node;
+	struct drm_panel *panel;
+	struct dvo_config *config;
+	bool enabled;
+	struct drm_encoder *encoder;
+};
+
+struct sti_dvo_connector {
+	struct drm_connector drm_connector;
+	struct drm_encoder *encoder;
+	struct sti_dvo *dvo;
+};
+
+#define to_sti_dvo_connector(x) \
+	container_of(x, struct sti_dvo_connector, drm_connector)
+
+#define BLANKING_LEVEL 16
+int dvo_awg_generate_code(struct sti_dvo *dvo, u8 *ram_size, u32 *ram_code)
+{
+	struct drm_display_mode *mode = &dvo->mode;
+	struct dvo_config *config = dvo->config;
+	struct awg_code_generation_params fw_gen_params;
+	struct awg_timing timing;
+
+	fw_gen_params.ram_code = ram_code;
+	fw_gen_params.instruction_offset = 0;
+
+	timing.total_lines = mode->vtotal;
+	timing.active_lines = mode->vdisplay;
+	timing.blanking_lines = mode->vsync_start - mode->vdisplay;
+	timing.trailing_lines = mode->vtotal - mode->vsync_start;
+	timing.total_pixels = mode->htotal;
+	timing.active_pixels = mode->hdisplay;
+	timing.blanking_pixels = mode->hsync_start - mode->hdisplay;
+	timing.trailing_pixels = mode->htotal - mode->hsync_start;
+	timing.blanking_level = BLANKING_LEVEL;
+
+	if (config->awg_fwgen_fct(&fw_gen_params, &timing)) {
+		DRM_ERROR("AWG firmware not properly generated\n");
+		return -EINVAL;
+	}
+
+	*ram_size = fw_gen_params.instruction_offset;
+
+	return 0;
+}
+
+/* Configure AWG, writing instructions
+ *
+ * @dvo: pointer to DVO structure
+ * @awg_ram_code: pointer to AWG instructions table
+ * @nb: nb of AWG instructions
+ */
+static void dvo_awg_configure(struct sti_dvo *dvo, u32 *awg_ram_code, int nb)
+{
+	int i;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	for (i = 0; i < nb; i++)
+		writel(awg_ram_code[i],
+		       dvo->regs + DVO_DIGSYNC_INSTR_I + i * 4);
+	for (i = nb; i < AWG_MAX_INST; i++)
+		writel(0, dvo->regs + DVO_DIGSYNC_INSTR_I + i * 4);
+
+	writel(DVO_AWG_CTRL_EN, dvo->regs + DVO_AWG_DIGSYNC_CTRL);
+}
+
+static void sti_dvo_disable(struct drm_bridge *bridge)
+{
+	struct sti_dvo *dvo = bridge->driver_private;
+
+	if (!dvo->enabled)
+		return;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	if (dvo->config->awg_fwgen_fct)
+		writel(0x00000000, dvo->regs + DVO_AWG_DIGSYNC_CTRL);
+
+	writel(0x00000000, dvo->regs + DVO_DOF_CFG);
+
+	if (dvo->panel)
+		dvo->panel->funcs->disable(dvo->panel);
+
+	/* Disable/unprepare dvo clock */
+	clk_disable_unprepare(dvo->clk_pix);
+	clk_disable_unprepare(dvo->clk);
+
+	dvo->enabled = false;
+}
+
+static void sti_dvo_pre_enable(struct drm_bridge *bridge)
+{
+	struct sti_dvo *dvo = bridge->driver_private;
+	struct dvo_config *config = dvo->config;
+	u32 val;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	if (dvo->enabled)
+		return;
+
+	/* Make sure DVO is disabled */
+	writel(0x00000000, dvo->regs + DVO_DOF_CFG);
+	writel(0x00000000, dvo->regs + DVO_AWG_DIGSYNC_CTRL);
+
+	if (config->awg_fwgen_fct) {
+		u8 nb_instr;
+		u32 awg_ram_code[AWG_MAX_INST];
+		/* Configure AWG */
+		if (!dvo_awg_generate_code(dvo, &nb_instr, awg_ram_code))
+			dvo_awg_configure(dvo, awg_ram_code, nb_instr);
+		else
+			return;
+	}
+
+	/* Prepare/enable clocks */
+	if (clk_prepare_enable(dvo->clk_pix))
+		DRM_ERROR("Failed to prepare/enable dvo_pix clk\n");
+	if (clk_prepare_enable(dvo->clk))
+		DRM_ERROR("Failed to prepare/enable dvo clk\n");
+
+	if (dvo->panel)
+		dvo->panel->funcs->enable(dvo->panel);
+
+	/* Set LUT */
+	writel(config->lowbyte,  dvo->regs + DVO_LUT_PROG_LOW);
+	writel(config->midbyte,  dvo->regs + DVO_LUT_PROG_MID);
+	writel(config->highbyte, dvo->regs + DVO_LUT_PROG_HIGH);
+
+	/* Digital output formatter config */
+	val = (config->flags | DVO_DOF_EN);
+	writel(val, dvo->regs + DVO_DOF_CFG);
+
+	dvo->enabled = true;
+}
+
+static void sti_dvo_set_mode(struct drm_bridge *bridge,
+			     struct drm_display_mode *mode,
+			     struct drm_display_mode *adjusted_mode)
+{
+	struct sti_dvo *dvo = bridge->driver_private;
+	struct sti_mixer *mixer = to_sti_mixer(dvo->encoder->crtc);
+	int rate = mode->clock * 1000;
+	struct clk *clkp;
+	int ret;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	memcpy(&dvo->mode, mode, sizeof(struct drm_display_mode));
+
+	/* According to the path used (main or aux), the dvo clocks should
+	 * have a different parent clock. */
+	if (mixer->id == STI_MIXER_MAIN)
+		clkp = dvo->clk_main_parent;
+	else
+		clkp = dvo->clk_aux_parent;
+
+	if (clkp) {
+		clk_set_parent(dvo->clk_pix, clkp);
+		clk_set_parent(dvo->clk, clkp);
+	}
+
+	/* DVO clocks = compositor clock */
+	ret = clk_set_rate(dvo->clk_pix, rate);
+	if (ret < 0) {
+		DRM_ERROR("Cannot set rate (%dHz) for dvo_pix clk\n", rate);
+		return;
+	}
+
+	ret = clk_set_rate(dvo->clk, rate);
+	if (ret < 0) {
+		DRM_ERROR("Cannot set rate (%dHz) for dvo clk\n", rate);
+		return;
+	}
+
+	/* For now, we only support 24bit data enable (DE) synchro format */
+	dvo->config = &rgb_24bit_de_cfg;
+}
+
+static void sti_dvo_bridge_nope(struct drm_bridge *bridge)
+{
+	/* do nothing */
+}
+
+static void sti_dvo_brigde_destroy(struct drm_bridge *bridge)
+{
+	drm_bridge_cleanup(bridge);
+	kfree(bridge);
+}
+
+static const struct drm_bridge_funcs sti_dvo_bridge_funcs = {
+	.pre_enable = sti_dvo_pre_enable,
+	.enable = sti_dvo_bridge_nope,
+	.disable = sti_dvo_disable,
+	.post_disable = sti_dvo_bridge_nope,
+	.mode_set = sti_dvo_set_mode,
+	.destroy = sti_dvo_brigde_destroy,
+};
+
+static int sti_dvo_connector_get_modes(struct drm_connector *connector)
+{
+	struct sti_dvo_connector *dvo_connector
+		= to_sti_dvo_connector(connector);
+	struct sti_dvo *dvo = dvo_connector->dvo;
+
+	if (dvo->panel)
+		return dvo->panel->funcs->get_modes(dvo->panel);
+
+	return 0;
+}
+
+#define CLK_TOLERANCE_HZ 50
+
+static int sti_dvo_connector_mode_valid(struct drm_connector *connector,
+					struct drm_display_mode *mode)
+{
+	int target = mode->clock * 1000;
+	int target_min = target - CLK_TOLERANCE_HZ;
+	int target_max = target + CLK_TOLERANCE_HZ;
+	int result;
+	struct sti_dvo_connector *dvo_connector
+		= to_sti_dvo_connector(connector);
+	struct sti_dvo *dvo = dvo_connector->dvo;
+
+	result = clk_round_rate(dvo->clk_pix, target);
+
+	DRM_DEBUG_DRIVER("target rate = %d => available rate = %d\n",
+			 target, result);
+
+	if ((result < target_min) || (result > target_max)) {
+		DRM_DEBUG_DRIVER("dvo pixclk=%d not supported\n", target);
+		return MODE_BAD;
+	}
+
+	return MODE_OK;
+}
+
+struct drm_encoder *sti_dvo_best_encoder(struct drm_connector *connector)
+{
+	struct sti_dvo_connector *dvo_connector
+		= to_sti_dvo_connector(connector);
+
+	/* Best encoder is the one associated during connector creation */
+	return dvo_connector->encoder;
+}
+
+static struct drm_connector_helper_funcs sti_dvo_connector_helper_funcs = {
+	.get_modes = sti_dvo_connector_get_modes,
+	.mode_valid = sti_dvo_connector_mode_valid,
+	.best_encoder = sti_dvo_best_encoder,
+};
+
+static enum drm_connector_status
+sti_dvo_connector_detect(struct drm_connector *connector, bool force)
+{
+	struct sti_dvo_connector *dvo_connector
+		= to_sti_dvo_connector(connector);
+	struct sti_dvo *dvo = dvo_connector->dvo;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	if (!dvo->panel)
+		dvo->panel = of_drm_find_panel(dvo->panel_node);
+
+	if (dvo->panel)
+		if (!drm_panel_attach(dvo->panel, connector))
+			return connector_status_connected;
+
+	return connector_status_disconnected;
+}
+
+static void sti_dvo_connector_destroy(struct drm_connector *connector)
+{
+	struct sti_dvo_connector *dvo_connector
+		= to_sti_dvo_connector(connector);
+
+	drm_connector_unregister(connector);
+	drm_connector_cleanup(connector);
+	kfree(dvo_connector);
+}
+
+static struct drm_connector_funcs sti_dvo_connector_funcs = {
+	.dpms = drm_helper_connector_dpms,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.detect = sti_dvo_connector_detect,
+	.destroy = sti_dvo_connector_destroy,
+};
+
+static struct drm_encoder *sti_dvo_find_encoder(struct drm_device *dev)
+{
+	struct drm_encoder *encoder;
+
+	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
+		if (encoder->encoder_type == DRM_MODE_ENCODER_LVDS)
+			return encoder;
+	}
+
+	return NULL;
+}
+
+static int sti_dvo_bind(struct device *dev, struct device *master, void *data)
+{
+	struct sti_dvo *dvo = dev_get_drvdata(dev);
+	struct drm_device *drm_dev = data;
+	struct drm_encoder *encoder;
+	struct sti_dvo_connector *connector;
+	struct drm_connector *drm_connector;
+	struct drm_bridge *bridge;
+	int err;
+
+	/* Set the drm device handle */
+	dvo->drm_dev = drm_dev;
+
+	encoder = sti_dvo_find_encoder(drm_dev);
+	if (!encoder)
+		return -ENOMEM;
+
+	connector = devm_kzalloc(dev, sizeof(*connector), GFP_KERNEL);
+	if (!connector)
+		return -ENOMEM;
+
+	connector->dvo = dvo;
+
+	bridge = devm_kzalloc(dev, sizeof(*bridge), GFP_KERNEL);
+	if (!bridge)
+		return -ENOMEM;
+
+	bridge->driver_private = dvo;
+	drm_bridge_init(drm_dev, bridge, &sti_dvo_bridge_funcs);
+
+	encoder->bridge = bridge;
+	connector->encoder = encoder;
+	dvo->encoder = encoder;
+
+	drm_connector = (struct drm_connector *)connector;
+
+	drm_connector->polled = DRM_CONNECTOR_POLL_HPD;
+
+	drm_connector_init(drm_dev, drm_connector,
+			   &sti_dvo_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
+	drm_connector_helper_add(drm_connector,
+				 &sti_dvo_connector_helper_funcs);
+
+	err = drm_connector_register(drm_connector);
+	if (err)
+		goto err_connector;
+
+	err = drm_mode_connector_attach_encoder(drm_connector, encoder);
+	if (err) {
+		DRM_ERROR("Failed to attach a connector to a encoder\n");
+		goto err_sysfs;
+	}
+
+	return 0;
+
+err_sysfs:
+	drm_connector_unregister(drm_connector);
+err_connector:
+	drm_bridge_cleanup(bridge);
+	drm_connector_cleanup(drm_connector);
+	return -EINVAL;
+}
+
+static void sti_dvo_unbind(struct device *dev,
+			   struct device *master, void *data)
+{
+	/* do nothing */
+}
+
+static const struct component_ops sti_dvo_ops = {
+	.bind = sti_dvo_bind,
+	.unbind = sti_dvo_unbind,
+};
+
+static int sti_dvo_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct sti_dvo *dvo;
+	struct resource *res;
+	struct device_node *np = dev->of_node;
+
+	DRM_INFO("%s\n", __func__);
+
+	dvo = devm_kzalloc(dev, sizeof(*dvo), GFP_KERNEL);
+	if (!dvo) {
+		DRM_ERROR("Failed to allocate memory for DVO\n");
+		return -ENOMEM;
+	}
+
+	dvo->dev = pdev->dev;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dvo-reg");
+	if (!res) {
+		DRM_ERROR("Invalid dvo resource\n");
+		return -ENOMEM;
+	}
+	dvo->regs = devm_ioremap_nocache(dev, res->start,
+			resource_size(res));
+	if (IS_ERR(dvo->regs))
+		return PTR_ERR(dvo->regs);
+
+	dvo->clk_pix = devm_clk_get(dev, "dvo_pix");
+	if (IS_ERR(dvo->clk_pix)) {
+		DRM_ERROR("Cannot get dvo_pix clock\n");
+		return PTR_ERR(dvo->clk_pix);
+	}
+
+	dvo->clk = devm_clk_get(dev, "dvo");
+	if (IS_ERR(dvo->clk)) {
+		DRM_ERROR("Cannot get dvo clock\n");
+		return PTR_ERR(dvo->clk);
+	}
+
+	dvo->clk_main_parent = devm_clk_get(dev, "main_parent");
+	if (IS_ERR(dvo->clk_main_parent)) {
+		DRM_DEBUG_DRIVER("Cannot get main_parent clock\n");
+		dvo->clk_main_parent = NULL;
+	}
+
+	dvo->clk_aux_parent = devm_clk_get(dev, "aux_parent");
+	if (IS_ERR(dvo->clk_aux_parent)) {
+		DRM_DEBUG_DRIVER("Cannot get aux_parent clock\n");
+		dvo->clk_aux_parent = NULL;
+	}
+
+	dvo->panel_node = of_parse_phandle(np, "sti,panel", 0);
+	if (!dvo->panel_node)
+		DRM_ERROR("No panel associated to the dvo output\n");
+
+	platform_set_drvdata(pdev, dvo);
+
+	return component_add(&pdev->dev, &sti_dvo_ops);
+}
+
+static int sti_dvo_remove(struct platform_device *pdev)
+{
+	component_del(&pdev->dev, &sti_dvo_ops);
+	return 0;
+}
+
+static struct of_device_id dvo_of_match[] = {
+	{ .compatible = "st,stih407-dvo", },
+	{ /* end node */ }
+};
+MODULE_DEVICE_TABLE(of, dvo_of_match);
+
+struct platform_driver sti_dvo_driver = {
+	.driver = {
+		.name = "sti-dvo",
+		.owner = THIS_MODULE,
+		.of_match_table = dvo_of_match,
+	},
+	.probe = sti_dvo_probe,
+	.remove = sti_dvo_remove,
+};
+
+module_platform_driver(sti_dvo_driver);
+
+MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
+MODULE_LICENSE("GPL");