--- /dev/null
+/*
+ * Copyright (C) STMicroelectronics SA 2014
+ * Authors: Benjamin Gaignard <benjamin.gaignard@st.com>
+ * Fabien Dessenne <fabien.dessenne@st.com>
+ * Vincent Abriou <vincent.abriou@st.com>
+ * for STMicroelectronics.
+ * License terms: GNU General Public License (GPL), version 2
+ */
+
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/platform_device.h>
+
+#include <drm/drmP.h>
+
+#include "sti_vtg.h"
+
+#define VTG_TYPE_MASTER 0
+#define VTG_TYPE_SLAVE_BY_EXT0 1
+
+/* registers offset */
+#define VTG_MODE 0x0000
+#define VTG_CLKLN 0x0008
+#define VTG_HLFLN 0x000C
+#define VTG_DRST_AUTOC 0x0010
+#define VTG_VID_TFO 0x0040
+#define VTG_VID_TFS 0x0044
+#define VTG_VID_BFO 0x0048
+#define VTG_VID_BFS 0x004C
+
+#define VTG_HOST_ITS 0x0078
+#define VTG_HOST_ITS_BCLR 0x007C
+#define VTG_HOST_ITM_BCLR 0x0088
+#define VTG_HOST_ITM_BSET 0x008C
+
+#define VTG_H_HD_1 0x00C0
+#define VTG_TOP_V_VD_1 0x00C4
+#define VTG_BOT_V_VD_1 0x00C8
+#define VTG_TOP_V_HD_1 0x00CC
+#define VTG_BOT_V_HD_1 0x00D0
+
+#define VTG_H_HD_2 0x00E0
+#define VTG_TOP_V_VD_2 0x00E4
+#define VTG_BOT_V_VD_2 0x00E8
+#define VTG_TOP_V_HD_2 0x00EC
+#define VTG_BOT_V_HD_2 0x00F0
+
+#define VTG_H_HD_3 0x0100
+#define VTG_TOP_V_VD_3 0x0104
+#define VTG_BOT_V_VD_3 0x0108
+#define VTG_TOP_V_HD_3 0x010C
+#define VTG_BOT_V_HD_3 0x0110
+
+#define VTG_IRQ_BOTTOM BIT(0)
+#define VTG_IRQ_TOP BIT(1)
+#define VTG_IRQ_MASK (VTG_IRQ_TOP | VTG_IRQ_BOTTOM)
+
+/* delay introduced by the Arbitrary Waveform Generator in nb of pixels */
+#define AWG_DELAY_HD (-9)
+#define AWG_DELAY_ED (-8)
+#define AWG_DELAY_SD (-7)
+
+LIST_HEAD(vtg_lookup);
+
+/**
+ * STI VTG structure
+ *
+ * @dev: pointer to device driver
+ * @data: data associated to the device
+ * @irq: VTG irq
+ * @type: VTG type (main or aux)
+ * @notifier_list: notifier callback
+ * @crtc_id: the crtc id for vblank event
+ * @slave: slave vtg
+ * @link: List node to link the structure in lookup list
+ */
+struct sti_vtg {
+ struct device *dev;
+ struct device_node *np;
+ void __iomem *regs;
+ int irq;
+ u32 irq_status;
+ struct raw_notifier_head notifier_list;
+ int crtc_id;
+ struct sti_vtg *slave;
+ struct list_head link;
+};
+
+static void vtg_register(struct sti_vtg *vtg)
+{
+ list_add_tail(&vtg->link, &vtg_lookup);
+}
+
+struct sti_vtg *of_vtg_find(struct device_node *np)
+{
+ struct sti_vtg *vtg;
+
+ list_for_each_entry(vtg, &vtg_lookup, link) {
+ if (vtg->np == np)
+ return vtg;
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(of_vtg_find);
+
+static void vtg_reset(struct sti_vtg *vtg)
+{
+ /* reset slave and then master */
+ if (vtg->slave)
+ vtg_reset(vtg->slave);
+
+ writel(1, vtg->regs + VTG_DRST_AUTOC);
+}
+
+static void vtg_set_mode(struct sti_vtg *vtg,
+ int type, const struct drm_display_mode *mode)
+{
+ u32 tmp;
+
+ if (vtg->slave)
+ vtg_set_mode(vtg->slave, VTG_TYPE_SLAVE_BY_EXT0, mode);
+
+ writel(mode->htotal, vtg->regs + VTG_CLKLN);
+ writel(mode->vtotal * 2, vtg->regs + VTG_HLFLN);
+
+ tmp = (mode->vtotal - mode->vsync_start + 1) << 16;
+ tmp |= mode->htotal - mode->hsync_start;
+ writel(tmp, vtg->regs + VTG_VID_TFO);
+ writel(tmp, vtg->regs + VTG_VID_BFO);
+
+ tmp = (mode->vdisplay + mode->vtotal - mode->vsync_start + 1) << 16;
+ tmp |= mode->hdisplay + mode->htotal - mode->hsync_start;
+ writel(tmp, vtg->regs + VTG_VID_TFS);
+ writel(tmp, vtg->regs + VTG_VID_BFS);
+
+ /* prepare VTG set 1 and 2 for HDMI and VTG set 3 for HD DAC */
+ tmp = (mode->hsync_end - mode->hsync_start) << 16;
+ writel(tmp, vtg->regs + VTG_H_HD_1);
+ writel(tmp, vtg->regs + VTG_H_HD_2);
+
+ tmp = (mode->vsync_end - mode->vsync_start + 1) << 16;
+ tmp |= 1;
+ writel(tmp, vtg->regs + VTG_TOP_V_VD_1);
+ writel(tmp, vtg->regs + VTG_BOT_V_VD_1);
+ writel(0, vtg->regs + VTG_TOP_V_HD_1);
+ writel(0, vtg->regs + VTG_BOT_V_HD_1);
+
+ /* prepare VTG set 2 for for HD DCS */
+ writel(tmp, vtg->regs + VTG_TOP_V_VD_2);
+ writel(tmp, vtg->regs + VTG_BOT_V_VD_2);
+ writel(0, vtg->regs + VTG_TOP_V_HD_2);
+ writel(0, vtg->regs + VTG_BOT_V_HD_2);
+
+ /* prepare VTG set 3 for HD Analog in HD mode */
+ tmp = (mode->hsync_end - mode->hsync_start + AWG_DELAY_HD) << 16;
+ tmp |= mode->htotal + AWG_DELAY_HD;
+ writel(tmp, vtg->regs + VTG_H_HD_3);
+
+ tmp = (mode->vsync_end - mode->vsync_start) << 16;
+ tmp |= mode->vtotal;
+ writel(tmp, vtg->regs + VTG_TOP_V_VD_3);
+ writel(tmp, vtg->regs + VTG_BOT_V_VD_3);
+
+ tmp = (mode->htotal + AWG_DELAY_HD) << 16;
+ tmp |= mode->htotal + AWG_DELAY_HD;
+ writel(tmp, vtg->regs + VTG_TOP_V_HD_3);
+ writel(tmp, vtg->regs + VTG_BOT_V_HD_3);
+
+ /* mode */
+ writel(type, vtg->regs + VTG_MODE);
+}
+
+static void vtg_enable_irq(struct sti_vtg *vtg)
+{
+ /* clear interrupt status and mask */
+ writel(0xFFFF, vtg->regs + VTG_HOST_ITS_BCLR);
+ writel(0xFFFF, vtg->regs + VTG_HOST_ITM_BCLR);
+ writel(VTG_IRQ_MASK, vtg->regs + VTG_HOST_ITM_BSET);
+}
+
+void sti_vtg_set_config(struct sti_vtg *vtg,
+ const struct drm_display_mode *mode)
+{
+ /* write configuration */
+ vtg_set_mode(vtg, VTG_TYPE_MASTER, mode);
+
+ vtg_reset(vtg);
+
+ /* enable irq for the vtg vblank synchro */
+ if (vtg->slave)
+ vtg_enable_irq(vtg->slave);
+ else
+ vtg_enable_irq(vtg);
+}
+EXPORT_SYMBOL(sti_vtg_set_config);
+
+/**
+ * sti_vtg_get_line_number
+ *
+ * @mode: display mode to be used
+ * @y: line
+ *
+ * Return the line number according to the display mode taking
+ * into account the Sync and Back Porch information.
+ * Video frame line numbers start at 1, y starts at 0.
+ * In interlaced modes the start line is the field line number of the odd
+ * field, but y is still defined as a progressive frame.
+ */
+u32 sti_vtg_get_line_number(struct drm_display_mode mode, int y)
+{
+ u32 start_line = mode.vtotal - mode.vsync_start + 1;
+
+ if (mode.flags & DRM_MODE_FLAG_INTERLACE)
+ start_line *= 2;
+
+ return start_line + y;
+}
+EXPORT_SYMBOL(sti_vtg_get_line_number);
+
+/**
+ * sti_vtg_get_pixel_number
+ *
+ * @mode: display mode to be used
+ * @x: row
+ *
+ * Return the pixel number according to the display mode taking
+ * into account the Sync and Back Porch information.
+ * Pixels are counted from 0.
+ */
+u32 sti_vtg_get_pixel_number(struct drm_display_mode mode, int x)
+{
+ return mode.htotal - mode.hsync_start + x;
+}
+EXPORT_SYMBOL(sti_vtg_get_pixel_number);
+
+int sti_vtg_register_client(struct sti_vtg *vtg,
+ struct notifier_block *nb, int crtc_id)
+{
+ if (vtg->slave)
+ return sti_vtg_register_client(vtg->slave, nb, crtc_id);
+
+ vtg->crtc_id = crtc_id;
+ return raw_notifier_chain_register(&vtg->notifier_list, nb);
+}
+EXPORT_SYMBOL(sti_vtg_register_client);
+
+int sti_vtg_unregister_client(struct sti_vtg *vtg, struct notifier_block *nb)
+{
+ if (vtg->slave)
+ return sti_vtg_unregister_client(vtg->slave, nb);
+
+ return raw_notifier_chain_unregister(&vtg->notifier_list, nb);
+}
+EXPORT_SYMBOL(sti_vtg_unregister_client);
+
+static irqreturn_t vtg_irq_thread(int irq, void *arg)
+{
+ struct sti_vtg *vtg = arg;
+ u32 event;
+
+ event = (vtg->irq_status & VTG_IRQ_TOP) ?
+ VTG_TOP_FIELD_EVENT : VTG_BOTTOM_FIELD_EVENT;
+
+ raw_notifier_call_chain(&vtg->notifier_list, event, &vtg->crtc_id);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t vtg_irq(int irq, void *arg)
+{
+ struct sti_vtg *vtg = arg;
+
+ vtg->irq_status = readl(vtg->regs + VTG_HOST_ITS);
+
+ writel(vtg->irq_status, vtg->regs + VTG_HOST_ITS_BCLR);
+
+ /* force sync bus write */
+ readl(vtg->regs + VTG_HOST_ITS);
+
+ return IRQ_WAKE_THREAD;
+}
+
+static int vtg_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np;
+ struct sti_vtg *vtg;
+ struct resource *res;
+ char irq_name[32];
+ int ret;
+
+ vtg = devm_kzalloc(dev, sizeof(*vtg), GFP_KERNEL);
+ if (!vtg)
+ return -ENOMEM;
+
+ vtg->dev = dev;
+ vtg->np = pdev->dev.of_node;
+
+ /* Get Memory ressources */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ DRM_ERROR("Get memory resource failed\n");
+ return -ENOMEM;
+ }
+ vtg->regs = devm_ioremap_nocache(dev, res->start, resource_size(res));
+
+ np = of_parse_phandle(pdev->dev.of_node, "st,slave", 0);
+ if (np) {
+ vtg->slave = of_vtg_find(np);
+
+ if (!vtg->slave)
+ return -EPROBE_DEFER;
+ } else {
+ vtg->irq = platform_get_irq(pdev, 0);
+ if (IS_ERR_VALUE(vtg->irq)) {
+ DRM_ERROR("Failed to get VTG interrupt\n");
+ return vtg->irq;
+ }
+
+ snprintf(irq_name, sizeof(irq_name), "vsync-%s",
+ dev_name(vtg->dev));
+
+ RAW_INIT_NOTIFIER_HEAD(&vtg->notifier_list);
+
+ ret = devm_request_threaded_irq(dev, vtg->irq, vtg_irq,
+ vtg_irq_thread, IRQF_ONESHOT, irq_name, vtg);
+ if (IS_ERR_VALUE(ret)) {
+ DRM_ERROR("Failed to register VTG interrupt\n");
+ return ret;
+ }
+ }
+
+ vtg_register(vtg);
+ platform_set_drvdata(pdev, vtg);
+
+ DRM_INFO("%s %s\n", __func__, dev_name(vtg->dev));
+
+ return 0;
+}
+
+static int vtg_remove(struct platform_device *pdev)
+{
+ return 0;
+}
+
+static const struct of_device_id vtg_of_match[] = {
+ { .compatible = "st,vtg", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, vtg_of_match);
+
+struct platform_driver sti_vtg_driver = {
+ .driver = {
+ .name = "sti-vtg",
+ .owner = THIS_MODULE,
+ .of_match_table = vtg_of_match,
+ },
+ .probe = vtg_probe,
+ .remove = vtg_remove,
+};
+
+module_platform_driver(sti_vtg_driver);
+
+MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
+MODULE_LICENSE("GPL");