From 601b6a88cd14e655ccd246fe122cbf496a891cbb Mon Sep 17 00:00:00 2001
From: Alexander Bersenev <bay@hackerdom.ru>
Date: Mon, 9 Jun 2014 00:08:10 +0600
Subject: [PATCH] rc: add sunxi-ir driver

This patch adds driver for sunxi IR controller.
It is based on Alexsey Shestacov's work based on the original driver
supplied by Allwinner.

Signed-off-by: Alexander Bersenev <bay@hackerdom.ru>
Signed-off-by: Alexsey Shestacov <wingrime@linux-sunxi.org>
---
 drivers/media/rc/Kconfig     |  10 ++
 drivers/media/rc/Makefile    |   1 +
 drivers/media/rc/sunxi-cir.c | 318 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 329 insertions(+)
 create mode 100644 drivers/media/rc/sunxi-cir.c

diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig
index 8fbd377..9427fad 100644
--- a/drivers/media/rc/Kconfig
+++ b/drivers/media/rc/Kconfig
@@ -343,4 +343,14 @@ config RC_ST
 
 	 If you're not sure, select N here.
 
+config IR_SUNXI
+    tristate "SUNXI IR remote control"
+    depends on RC_CORE
+    depends on ARCH_SUNXI
+    ---help---
+      Say Y if you want to use sunXi internal IR Controller
+
+      To compile this driver as a module, choose M here: the module will
+      be called sunxi-ir.
+
 endif #RC_DEVICES
diff --git a/drivers/media/rc/Makefile b/drivers/media/rc/Makefile
index f8b54ff..9ee9ee7 100644
--- a/drivers/media/rc/Makefile
+++ b/drivers/media/rc/Makefile
@@ -32,3 +32,4 @@ obj-$(CONFIG_IR_GPIO_CIR) += gpio-ir-recv.o
 obj-$(CONFIG_IR_IGUANA) += iguanair.o
 obj-$(CONFIG_IR_TTUSBIR) += ttusbir.o
 obj-$(CONFIG_RC_ST) += st_rc.o
+obj-$(CONFIG_IR_SUNXI) += sunxi-cir.o
diff --git a/drivers/media/rc/sunxi-cir.c b/drivers/media/rc/sunxi-cir.c
new file mode 100644
index 0000000..5971b69
--- /dev/null
+++ b/drivers/media/rc/sunxi-cir.c
@@ -0,0 +1,318 @@
+/*
+ * Driver for Allwinner sunXi IR controller
+ *
+ * Copyright (C) 2014 Alexsey Shestacov <wingrime@linux-sunxi.org>
+ * Copyright (C) 2014 Alexander Bersenev <bay@hackerdom.ru>
+ *
+ * Based on sun5i-ir.c:
+ * Copyright (C) 2007-2012 Daniel Wang
+ * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <media/rc-core.h>
+
+#define SUNXI_IR_DEV "sunxi-ir"
+
+/* Registers */
+/* IR Control */
+#define SUNXI_IR_CTL_REG      0x00
+/* Global Enable */
+#define REG_CTL_GEN			BIT(0)
+/* RX block enable */
+#define REG_CTL_RXEN			BIT(1)
+/* CIR mode */
+#define REG_CTL_MD			(BIT(4) | BIT(5))
+
+/* Rx Config */
+#define SUNXI_IR_RXCTL_REG    0x10
+/* Pulse Polarity Invert flag */
+#define REG_RXCTL_RPPI			BIT(2)
+
+/* Rx Data */
+#define SUNXI_IR_RXFIFO_REG   0x20
+
+/* Rx Interrupt Enable */
+#define SUNXI_IR_RXINT_REG    0x2C
+/* Rx FIFO Overflow */
+#define REG_RXINT_ROI_EN		BIT(0)
+/* Rx Packet End */
+#define REG_RXINT_RPEI_EN		BIT(1)
+/* Rx FIFO Data Available */
+#define REG_RXINT_RAI_EN		BIT(4)
+
+/* Rx FIFO available byte level */
+#define REG_RXINT_RAL(val)    (((val) << 8) & (GENMASK(11, 8)))
+
+/* Rx Interrupt Status */
+#define SUNXI_IR_RXSTA_REG    0x30
+/* RX FIFO Get Available Counter */
+#define REG_RXSTA_GET_AC(val) (((val) >> 8) & (GENMASK(5, 0)))
+/* Clear all interrupt status value */
+#define REG_RXSTA_CLEARALL    0xff
+
+/* IR Sample Config */
+#define SUNXI_IR_CIR_REG      0x34
+/* CIR_REG register noise threshold */
+#define REG_CIR_NTHR(val)    (((val) << 2) & (GENMASK(7, 2)))
+/* CIR_REG register idle threshold */
+#define REG_CIR_ITHR(val)    (((val) << 8) & (GENMASK(15, 8)))
+
+/* Hardware supported fifo size */
+#define SUNXI_IR_FIFO_SIZE    16
+/* How many messages in FIFO trigger IRQ */
+#define TRIGGER_LEVEL         8
+/* Required frequency for IR0 or IR1 clock in CIR mode */
+#define SUNXI_IR_BASE_CLK     8000000
+/* Frequency after IR internal divider  */
+#define SUNXI_IR_CLK          (SUNXI_IR_BASE_CLK / 64)
+/* Sample period in ns */
+#define SUNXI_IR_SAMPLE       (1000000000ul / SUNXI_IR_CLK)
+/* Noise threshold in samples  */
+#define SUNXI_IR_RXNOISE      1
+/* Idle Threshold in samples */
+#define SUNXI_IR_RXIDLE       20
+/* Time after which device stops sending data in ms */
+#define SUNXI_IR_TIMEOUT      120
+
+struct sunxi_ir {
+	spinlock_t      ir_lock;
+	struct rc_dev   *rc;
+	void __iomem    *base;
+	int             irq;
+	struct clk      *clk;
+	struct clk      *apb_clk;
+	const char      *map_name;
+};
+
+static irqreturn_t sunxi_ir_irq(int irqno, void *dev_id)
+{
+	unsigned long status;
+	unsigned char dt;
+	unsigned int cnt, rc;
+	struct sunxi_ir *ir = dev_id;
+	DEFINE_IR_RAW_EVENT(rawir);
+
+	spin_lock(&ir->ir_lock);
+
+	status = readl(ir->base + SUNXI_IR_RXSTA_REG);
+
+	/* clean all pending statuses */
+	writel(status | REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
+
+	if (status & REG_RXINT_RAI_EN) {
+		/* How many messages in fifo */
+		rc  = REG_RXSTA_GET_AC(status);
+		/* Sanity check */
+		rc = rc > SUNXI_IR_FIFO_SIZE ? SUNXI_IR_FIFO_SIZE : rc;
+		/* If we have data */
+		for (cnt = 0; cnt < rc; cnt++) {
+			/* for each bit in fifo */
+			dt = readb(ir->base + SUNXI_IR_RXFIFO_REG);
+			rawir.pulse = (dt & 0x80) != 0;
+			rawir.duration = ((dt & 0x7f) + 1) * SUNXI_IR_SAMPLE;
+			ir_raw_event_store_with_filter(ir->rc, &rawir);
+		}
+	}
+
+	if (status & REG_RXINT_ROI_EN) {
+		ir_raw_event_reset(ir->rc);
+	} else if (status & REG_RXINT_RPEI_EN) {
+		ir_raw_event_set_idle(ir->rc, true);
+		ir_raw_event_handle(ir->rc);
+	}
+
+	spin_unlock(&ir->ir_lock);
+
+	return IRQ_HANDLED;
+}
+
+static int sunxi_ir_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+	unsigned long tmp = 0;
+
+	struct device *dev = &pdev->dev;
+	struct device_node *dn = dev->of_node;
+	struct resource *res;
+	struct sunxi_ir *ir;
+
+	ir = devm_kzalloc(dev, sizeof(struct sunxi_ir), GFP_KERNEL);
+	if (!ir)
+		return -ENOMEM;
+
+	/* Clock */
+	ir->apb_clk = devm_clk_get(dev, "apb");
+	if (IS_ERR(ir->apb_clk)) {
+		dev_err(dev, "failed to get a apb clock.\n");
+		return PTR_ERR(ir->apb_clk);
+	}
+	ir->clk = devm_clk_get(dev, "ir");
+	if (IS_ERR(ir->clk)) {
+		dev_err(dev, "failed to get a ir clock.\n");
+		return PTR_ERR(ir->clk);
+	}
+
+	ret = clk_set_rate(ir->clk, SUNXI_IR_BASE_CLK);
+	if (ret) {
+		dev_err(dev, "set ir base clock failed!\n");
+		return ret;
+	}
+
+	if (clk_prepare_enable(ir->apb_clk)) {
+		dev_err(dev, "try to enable apb_ir_clk failed\n");
+		return -EINVAL;
+	}
+
+	if (clk_prepare_enable(ir->clk)) {
+		dev_err(dev, "try to enable ir_clk failed\n");
+		ret = -EINVAL;
+		goto exit_clkdisable_apb_clk;
+	}
+
+	/* IO */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	ir->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(ir->base)) {
+		dev_err(dev, "failed to map registers\n");
+		ret = PTR_ERR(ir->base);
+		goto exit_clkdisable_clk;
+	}
+
+	ir->rc = rc_allocate_device();
+	if (!ir->rc) {
+		dev_err(dev, "failed to allocate device\n");
+		ret = -ENOMEM;
+		goto exit_clkdisable_clk;
+	}
+
+	ir->rc->priv = ir;
+	ir->rc->input_name = SUNXI_IR_DEV;
+	ir->rc->input_phys = "sunxi-ir/input0";
+	ir->rc->input_id.bustype = BUS_HOST;
+	ir->rc->input_id.vendor = 0x0001;
+	ir->rc->input_id.product = 0x0001;
+	ir->rc->input_id.version = 0x0100;
+	ir->map_name = of_get_property(dn, "linux,rc-map-name", NULL);
+	ir->rc->map_name = ir->map_name ?: RC_MAP_EMPTY;
+	ir->rc->dev.parent = dev;
+	ir->rc->driver_type = RC_DRIVER_IR_RAW;
+	rc_set_allowed_protocols(ir->rc, RC_BIT_ALL);
+	ir->rc->rx_resolution = SUNXI_IR_SAMPLE;
+	ir->rc->timeout = MS_TO_NS(SUNXI_IR_TIMEOUT);
+	ir->rc->driver_name = SUNXI_IR_DEV;
+
+	ret = rc_register_device(ir->rc);
+	if (ret) {
+		dev_err(dev, "failed to register rc device\n");
+		goto exit_free_dev;
+	}
+
+	platform_set_drvdata(pdev, ir);
+
+	/* IRQ */
+	ir->irq = platform_get_irq(pdev, 0);
+	if (ir->irq < 0) {
+		dev_err(dev, "no irq resource\n");
+		ret = ir->irq;
+		goto exit_free_dev;
+	}
+
+	ret = devm_request_irq(dev, ir->irq, sunxi_ir_irq, 0, SUNXI_IR_DEV, ir);
+	if (ret) {
+		dev_err(dev, "failed request irq\n");
+		goto exit_free_dev;
+	}
+
+	/* Enable CIR Mode */
+	writel(REG_CTL_MD, ir->base+SUNXI_IR_CTL_REG);
+
+	/* Set noise threshold and idle threshold */
+	writel(REG_CIR_NTHR(SUNXI_IR_RXNOISE)|REG_CIR_ITHR(SUNXI_IR_RXIDLE),
+	       ir->base + SUNXI_IR_CIR_REG);
+
+	/* Invert Input Signal */
+	writel(REG_RXCTL_RPPI, ir->base + SUNXI_IR_RXCTL_REG);
+
+	/* Clear All Rx Interrupt Status */
+	writel(REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
+
+	/*
+	 * Enable IRQ on overflow, packet end, FIFO available with trigger
+	 * level
+	 */
+	writel(REG_RXINT_ROI_EN | REG_RXINT_RPEI_EN |
+	       REG_RXINT_RAI_EN | REG_RXINT_RAL(TRIGGER_LEVEL - 1),
+	       ir->base + SUNXI_IR_RXINT_REG);
+
+	/* Enable IR Module */
+	tmp = readl(ir->base + SUNXI_IR_CTL_REG);
+	writel(tmp | REG_CTL_GEN | REG_CTL_RXEN, ir->base + SUNXI_IR_CTL_REG);
+
+	dev_info(dev, "initialized sunXi IR driver\n");
+	return 0;
+
+exit_free_dev:
+	rc_free_device(ir->rc);
+exit_clkdisable_clk:
+	clk_disable_unprepare(ir->clk);
+exit_clkdisable_apb_clk:
+	clk_disable_unprepare(ir->apb_clk);
+
+	return ret;
+}
+
+static int sunxi_ir_remove(struct platform_device *pdev)
+{
+	unsigned long flags;
+	struct sunxi_ir *ir = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(ir->clk);
+	clk_disable_unprepare(ir->apb_clk);
+
+	spin_lock_irqsave(&ir->ir_lock, flags);
+	/* disable IR IRQ */
+	writel(0, ir->base + SUNXI_IR_RXINT_REG);
+	/* clear All Rx Interrupt Status */
+	writel(REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
+	/* disable IR */
+	writel(0, ir->base + SUNXI_IR_CTL_REG);
+	spin_unlock_irqrestore(&ir->ir_lock, flags);
+
+	rc_unregister_device(ir->rc);
+	return 0;
+}
+
+static const struct of_device_id sunxi_ir_match[] = {
+	{ .compatible = "allwinner,sun7i-a20-ir", },
+	{},
+};
+
+static struct platform_driver sunxi_ir_driver = {
+	.probe          = sunxi_ir_probe,
+	.remove         = sunxi_ir_remove,
+	.driver = {
+		.name = SUNXI_IR_DEV,
+		.owner = THIS_MODULE,
+		.of_match_table = sunxi_ir_match,
+	},
+};
+
+module_platform_driver(sunxi_ir_driver);
+
+MODULE_DESCRIPTION("Allwinner sunXi IR controller driver");
+MODULE_AUTHOR("Alexsey Shestacov <wingrime@linux-sunxi.org>");
+MODULE_LICENSE("GPL");
