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path: root/drivers/gpu/drm/mediatek/mtk_cec.c
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Diffstat (limited to 'drivers/gpu/drm/mediatek/mtk_cec.c')
-rw-r--r--drivers/gpu/drm/mediatek/mtk_cec.c258
1 files changed, 258 insertions, 0 deletions
diff --git a/drivers/gpu/drm/mediatek/mtk_cec.c b/drivers/gpu/drm/mediatek/mtk_cec.c
new file mode 100644
index 000000000..cdfa64891
--- /dev/null
+++ b/drivers/gpu/drm/mediatek/mtk_cec.c
@@ -0,0 +1,258 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2014 MediaTek Inc.
+ * Author: Jie Qiu <jie.qiu@mediatek.com>
+ */
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+
+#include "mtk_cec.h"
+
+#define TR_CONFIG 0x00
+#define CLEAR_CEC_IRQ BIT(15)
+
+#define CEC_CKGEN 0x04
+#define CEC_32K_PDN BIT(19)
+#define PDN BIT(16)
+
+#define RX_EVENT 0x54
+#define HDMI_PORD BIT(25)
+#define HDMI_HTPLG BIT(24)
+#define HDMI_PORD_INT_EN BIT(9)
+#define HDMI_HTPLG_INT_EN BIT(8)
+
+#define RX_GEN_WD 0x58
+#define HDMI_PORD_INT_32K_STATUS BIT(26)
+#define RX_RISC_INT_32K_STATUS BIT(25)
+#define HDMI_HTPLG_INT_32K_STATUS BIT(24)
+#define HDMI_PORD_INT_32K_CLR BIT(18)
+#define RX_INT_32K_CLR BIT(17)
+#define HDMI_HTPLG_INT_32K_CLR BIT(16)
+#define HDMI_PORD_INT_32K_STA_MASK BIT(10)
+#define RX_RISC_INT_32K_STA_MASK BIT(9)
+#define HDMI_HTPLG_INT_32K_STA_MASK BIT(8)
+#define HDMI_PORD_INT_32K_EN BIT(2)
+#define RX_INT_32K_EN BIT(1)
+#define HDMI_HTPLG_INT_32K_EN BIT(0)
+
+#define NORMAL_INT_CTRL 0x5C
+#define HDMI_HTPLG_INT_STA BIT(0)
+#define HDMI_PORD_INT_STA BIT(1)
+#define HDMI_HTPLG_INT_CLR BIT(16)
+#define HDMI_PORD_INT_CLR BIT(17)
+#define HDMI_FULL_INT_CLR BIT(20)
+
+struct mtk_cec {
+ void __iomem *regs;
+ struct clk *clk;
+ int irq;
+ bool hpd;
+ void (*hpd_event)(bool hpd, struct device *dev);
+ struct device *hdmi_dev;
+ spinlock_t lock;
+};
+
+static void mtk_cec_clear_bits(struct mtk_cec *cec, unsigned int offset,
+ unsigned int bits)
+{
+ void __iomem *reg = cec->regs + offset;
+ u32 tmp;
+
+ tmp = readl(reg);
+ tmp &= ~bits;
+ writel(tmp, reg);
+}
+
+static void mtk_cec_set_bits(struct mtk_cec *cec, unsigned int offset,
+ unsigned int bits)
+{
+ void __iomem *reg = cec->regs + offset;
+ u32 tmp;
+
+ tmp = readl(reg);
+ tmp |= bits;
+ writel(tmp, reg);
+}
+
+static void mtk_cec_mask(struct mtk_cec *cec, unsigned int offset,
+ unsigned int val, unsigned int mask)
+{
+ u32 tmp = readl(cec->regs + offset) & ~mask;
+
+ tmp |= val & mask;
+ writel(tmp, cec->regs + offset);
+}
+
+void mtk_cec_set_hpd_event(struct device *dev,
+ void (*hpd_event)(bool hpd, struct device *dev),
+ struct device *hdmi_dev)
+{
+ struct mtk_cec *cec = dev_get_drvdata(dev);
+ unsigned long flags;
+
+ spin_lock_irqsave(&cec->lock, flags);
+ cec->hdmi_dev = hdmi_dev;
+ cec->hpd_event = hpd_event;
+ spin_unlock_irqrestore(&cec->lock, flags);
+}
+
+bool mtk_cec_hpd_high(struct device *dev)
+{
+ struct mtk_cec *cec = dev_get_drvdata(dev);
+ unsigned int status;
+
+ status = readl(cec->regs + RX_EVENT);
+
+ return (status & (HDMI_PORD | HDMI_HTPLG)) == (HDMI_PORD | HDMI_HTPLG);
+}
+
+static void mtk_cec_htplg_irq_init(struct mtk_cec *cec)
+{
+ mtk_cec_mask(cec, CEC_CKGEN, 0 | CEC_32K_PDN, PDN | CEC_32K_PDN);
+ mtk_cec_set_bits(cec, RX_GEN_WD, HDMI_PORD_INT_32K_CLR |
+ RX_INT_32K_CLR | HDMI_HTPLG_INT_32K_CLR);
+ mtk_cec_mask(cec, RX_GEN_WD, 0, HDMI_PORD_INT_32K_CLR | RX_INT_32K_CLR |
+ HDMI_HTPLG_INT_32K_CLR | HDMI_PORD_INT_32K_EN |
+ RX_INT_32K_EN | HDMI_HTPLG_INT_32K_EN);
+}
+
+static void mtk_cec_htplg_irq_enable(struct mtk_cec *cec)
+{
+ mtk_cec_set_bits(cec, RX_EVENT, HDMI_PORD_INT_EN | HDMI_HTPLG_INT_EN);
+}
+
+static void mtk_cec_htplg_irq_disable(struct mtk_cec *cec)
+{
+ mtk_cec_clear_bits(cec, RX_EVENT, HDMI_PORD_INT_EN | HDMI_HTPLG_INT_EN);
+}
+
+static void mtk_cec_clear_htplg_irq(struct mtk_cec *cec)
+{
+ mtk_cec_set_bits(cec, TR_CONFIG, CLEAR_CEC_IRQ);
+ mtk_cec_set_bits(cec, NORMAL_INT_CTRL, HDMI_HTPLG_INT_CLR |
+ HDMI_PORD_INT_CLR | HDMI_FULL_INT_CLR);
+ mtk_cec_set_bits(cec, RX_GEN_WD, HDMI_PORD_INT_32K_CLR |
+ RX_INT_32K_CLR | HDMI_HTPLG_INT_32K_CLR);
+ usleep_range(5, 10);
+ mtk_cec_clear_bits(cec, NORMAL_INT_CTRL, HDMI_HTPLG_INT_CLR |
+ HDMI_PORD_INT_CLR | HDMI_FULL_INT_CLR);
+ mtk_cec_clear_bits(cec, TR_CONFIG, CLEAR_CEC_IRQ);
+ mtk_cec_clear_bits(cec, RX_GEN_WD, HDMI_PORD_INT_32K_CLR |
+ RX_INT_32K_CLR | HDMI_HTPLG_INT_32K_CLR);
+}
+
+static void mtk_cec_hpd_event(struct mtk_cec *cec, bool hpd)
+{
+ void (*hpd_event)(bool hpd, struct device *dev);
+ struct device *hdmi_dev;
+ unsigned long flags;
+
+ spin_lock_irqsave(&cec->lock, flags);
+ hpd_event = cec->hpd_event;
+ hdmi_dev = cec->hdmi_dev;
+ spin_unlock_irqrestore(&cec->lock, flags);
+
+ if (hpd_event)
+ hpd_event(hpd, hdmi_dev);
+}
+
+static irqreturn_t mtk_cec_htplg_isr_thread(int irq, void *arg)
+{
+ struct device *dev = arg;
+ struct mtk_cec *cec = dev_get_drvdata(dev);
+ bool hpd;
+
+ mtk_cec_clear_htplg_irq(cec);
+ hpd = mtk_cec_hpd_high(dev);
+
+ if (cec->hpd != hpd) {
+ dev_dbg(dev, "hotplug event! cur hpd = %d, hpd = %d\n",
+ cec->hpd, hpd);
+ cec->hpd = hpd;
+ mtk_cec_hpd_event(cec, hpd);
+ }
+ return IRQ_HANDLED;
+}
+
+static int mtk_cec_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mtk_cec *cec;
+ struct resource *res;
+ int ret;
+
+ cec = devm_kzalloc(dev, sizeof(*cec), GFP_KERNEL);
+ if (!cec)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, cec);
+ spin_lock_init(&cec->lock);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ cec->regs = devm_ioremap_resource(dev, res);
+ if (IS_ERR(cec->regs)) {
+ ret = PTR_ERR(cec->regs);
+ dev_err(dev, "Failed to ioremap cec: %d\n", ret);
+ return ret;
+ }
+
+ cec->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(cec->clk)) {
+ ret = PTR_ERR(cec->clk);
+ dev_err(dev, "Failed to get cec clock: %d\n", ret);
+ return ret;
+ }
+
+ cec->irq = platform_get_irq(pdev, 0);
+ if (cec->irq < 0)
+ return cec->irq;
+
+ ret = devm_request_threaded_irq(dev, cec->irq, NULL,
+ mtk_cec_htplg_isr_thread,
+ IRQF_SHARED | IRQF_TRIGGER_LOW |
+ IRQF_ONESHOT, "hdmi hpd", dev);
+ if (ret) {
+ dev_err(dev, "Failed to register cec irq: %d\n", ret);
+ return ret;
+ }
+
+ ret = clk_prepare_enable(cec->clk);
+ if (ret) {
+ dev_err(dev, "Failed to enable cec clock: %d\n", ret);
+ return ret;
+ }
+
+ mtk_cec_htplg_irq_init(cec);
+ mtk_cec_htplg_irq_enable(cec);
+
+ return 0;
+}
+
+static int mtk_cec_remove(struct platform_device *pdev)
+{
+ struct mtk_cec *cec = platform_get_drvdata(pdev);
+
+ mtk_cec_htplg_irq_disable(cec);
+ clk_disable_unprepare(cec->clk);
+ return 0;
+}
+
+static const struct of_device_id mtk_cec_of_ids[] = {
+ { .compatible = "mediatek,mt8173-cec", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, mtk_cec_of_ids);
+
+struct platform_driver mtk_cec_driver = {
+ .probe = mtk_cec_probe,
+ .remove = mtk_cec_remove,
+ .driver = {
+ .name = "mediatek-cec",
+ .of_match_table = mtk_cec_of_ids,
+ },
+};