[PATCH 1/3] media: rc: add driver for Amlogic Meson IR remote receiver

[Beniamino Galvani]

Amlogic Meson SoCs include a infrared remote control receiver that can
operate in two modes: in "NEC" mode the hardware can decode frames
using the NEC IR protocol, while in "general" mode the receiver simply
reports the duration of pulses and spaces for software decoding.

This is a driver for the IR receiver that uses software decoding of
received frames.

Signed-off-by: Beniamino Galvani <b.galvani@xxxxxxxxx>
---
 drivers/media/rc/Kconfig    |  11 +++
 drivers/media/rc/Makefile   |   1 +
 drivers/media/rc/meson-ir.c | 214 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 226 insertions(+)
 create mode 100644 drivers/media/rc/meson-ir.c

diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig
index 8ce0810..2d742e2 100644
--- a/drivers/media/rc/Kconfig
+++ b/drivers/media/rc/Kconfig
@@ -223,6 +223,17 @@ config IR_FINTEK
 	   To compile this driver as a module, choose M here: the
 	   module will be called fintek-cir.
 
+config IR_MESON
+	tristate "Amlogic Meson IR remote receiver"
+	depends on RC_CORE
+	depends on ARCH_MESON
+	---help---
+	   Say Y if you want to use the IR remote receiver available
+	   on Amlogic Meson SoCs.
+
+	   To compile this driver as a module, choose M here: the
+	   module will be called meson-ir.
+
 config IR_NUVOTON
 	tristate "Nuvoton w836x7hg Consumer Infrared Transceiver"
 	depends on PNP
diff --git a/drivers/media/rc/Makefile b/drivers/media/rc/Makefile
index 0989f94..06859bf 100644
--- a/drivers/media/rc/Makefile
+++ b/drivers/media/rc/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_IR_IMON) += imon.o
 obj-$(CONFIG_IR_ITE_CIR) += ite-cir.o
 obj-$(CONFIG_IR_MCEUSB) += mceusb.o
 obj-$(CONFIG_IR_FINTEK) += fintek-cir.o
+obj-$(CONFIG_IR_MESON) += meson-ir.o
 obj-$(CONFIG_IR_NUVOTON) += nuvoton-cir.o
 obj-$(CONFIG_IR_ENE) += ene_ir.o
 obj-$(CONFIG_IR_REDRAT3) += redrat3.o
diff --git a/drivers/media/rc/meson-ir.c b/drivers/media/rc/meson-ir.c
new file mode 100644
index 0000000..0900ece
--- /dev/null
+++ b/drivers/media/rc/meson-ir.c
@@ -0,0 +1,214 @@
+/*
+ * Driver for Amlogic Meson IR remote receiver
+ *
+ * Copyright (C) 2014 Beniamino Galvani <b.galvani@xxxxxxxxx>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/spinlock.h>
+
+#include <media/rc-core.h>
+
+#define DRIVER_NAME		"meson-ir"
+
+#define IR_DEC_LDR_ACTIVE	0x00
+#define IR_DEC_LDR_IDLE		0x04
+#define IR_DEC_LDR_REPEAT	0x08
+#define IR_DEC_BIT_0		0x0c
+#define IR_DEC_REG0		0x10
+#define IR_DEC_FRAME		0x14
+#define IR_DEC_STATUS		0x18
+#define IR_DEC_REG1		0x1c
+
+#define REG0_RATE_MASK		(BIT(11) - 1)
+
+#define REG1_MODE_MASK		(BIT(7) | BIT(8))
+#define REG1_MODE_NEC		(0 << 7)
+#define REG1_MODE_GENERAL	(2 << 7)
+
+#define REG1_TIME_IV_SHIFT	16
+#define REG1_TIME_IV_MASK	((BIT(13) - 1) << REG1_TIME_IV_SHIFT)
+
+#define REG1_IRQSEL_MASK	(BIT(2) | BIT(3))
+#define REG1_IRQSEL_NEC_MODE	(0 << 2)
+#define REG1_IRQSEL_RISE_FALL	(1 << 2)
+#define REG1_IRQSEL_FALL	(2 << 2)
+#define REG1_IRQSEL_RISE	(3 << 2)
+
+#define REG1_RESET		BIT(0)
+#define REG1_ENABLE		BIT(15)
+
+#define STATUS_IR_DEC_IN	BIT(8)
+
+#define MESON_TRATE		10	/* us */
+
+struct meson_ir {
+	void __iomem	*reg;
+	struct rc_dev	*rc;
+	int		irq;
+	spinlock_t	lock;
+};
+
+static void meson_ir_set_mask(struct meson_ir *ir, unsigned int reg,
+			      u32 mask, u32 value)
+{
+	u32 data;
+
+	data = readl(ir->reg + reg);
+	data &= ~mask;
+	data |= (value & mask);
+	writel(data, ir->reg + reg);
+}
+
+static irqreturn_t meson_ir_irq(int irqno, void *dev_id)
+{
+	struct meson_ir *ir = dev_id;
+	u32 duration;
+	DEFINE_IR_RAW_EVENT(rawir);
+
+	spin_lock(&ir->lock);
+
+	duration = readl(ir->reg + IR_DEC_REG1);
+	duration = (duration & REG1_TIME_IV_MASK) >> REG1_TIME_IV_SHIFT;
+	rawir.duration = US_TO_NS(duration * MESON_TRATE);
+
+	rawir.pulse = !!(readl(ir->reg + IR_DEC_STATUS) & STATUS_IR_DEC_IN);
+
+	ir_raw_event_store_with_filter(ir->rc, &rawir);
+	ir_raw_event_handle(ir->rc);
+
+	spin_unlock(&ir->lock);
+
+	return IRQ_HANDLED;
+}
+
+static int meson_ir_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *node = dev->of_node;
+	struct resource *res;
+	const char *map_name;
+	struct meson_ir *ir;
+	int ret;
+
+	ir = devm_kzalloc(dev, sizeof(struct meson_ir), GFP_KERNEL);
+	if (!ir)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	ir->reg = devm_ioremap_resource(dev, res);
+	if (IS_ERR(ir->reg)) {
+		dev_err(dev, "failed to map registers\n");
+		return PTR_ERR(ir->reg);
+	}
+
+	ir->irq = platform_get_irq(pdev, 0);
+	if (ir->irq < 0) {
+		dev_err(dev, "no irq resource\n");
+		return ir->irq;
+	}
+
+	ir->rc = rc_allocate_device();
+	if (!ir->rc) {
+		dev_err(dev, "failed to allocate rc device\n");
+		return -ENOMEM;
+	}
+
+	ir->rc->priv = ir;
+	ir->rc->input_name = DRIVER_NAME;
+	ir->rc->input_phys = DRIVER_NAME "/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;
+	map_name = of_get_property(node, "linux,rc-map-name", NULL);
+	ir->rc->map_name = map_name ? map_name : RC_MAP_EMPTY;
+	ir->rc->dev.parent = dev;
+	ir->rc->driver_type = RC_DRIVER_IR_RAW;
+	ir->rc->allowed_protocols = RC_BIT_ALL;
+	ir->rc->rx_resolution = US_TO_NS(MESON_TRATE);
+	ir->rc->timeout = MS_TO_NS(200);
+	ir->rc->driver_name = DRIVER_NAME;
+
+	spin_lock_init(&ir->lock);
+	platform_set_drvdata(pdev, ir);
+
+	ret = rc_register_device(ir->rc);
+	if (ret) {
+		dev_err(dev, "failed to register rc device\n");
+		goto out_free;
+	}
+
+	ret = devm_request_irq(dev, ir->irq, meson_ir_irq, 0, "ir-meson", ir);
+	if (ret) {
+		dev_err(dev, "failed to request irq\n");
+		goto out_unreg;
+	}
+
+	/* Reset the decoder */
+	meson_ir_set_mask(ir, IR_DEC_REG1, REG1_RESET, REG1_RESET);
+	meson_ir_set_mask(ir, IR_DEC_REG1, REG1_RESET, 0);
+	/* Set general operation mode */
+	meson_ir_set_mask(ir, IR_DEC_REG1, REG1_MODE_MASK, REG1_MODE_GENERAL);
+	/* Set rate */
+	meson_ir_set_mask(ir, IR_DEC_REG0, REG0_RATE_MASK, MESON_TRATE - 1);
+	/* IRQ on rising and falling edges */
+	meson_ir_set_mask(ir, IR_DEC_REG1, REG1_IRQSEL_MASK,
+			  REG1_IRQSEL_RISE_FALL);
+	/* Enable the decoder */
+	meson_ir_set_mask(ir, IR_DEC_REG1, REG1_ENABLE, REG1_ENABLE);
+
+	dev_info(dev, "receiver initialized\n");
+
+	return 0;
+out_unreg:
+	rc_unregister_device(ir->rc);
+out_free:
+	rc_free_device(ir->rc);
+
+	return ret;
+}
+
+static int meson_ir_remove(struct platform_device *pdev)
+{
+	struct meson_ir *ir = platform_get_drvdata(pdev);
+	unsigned long flags;
+
+	/* Disable the decoder */
+	spin_lock_irqsave(&ir->lock, flags);
+	meson_ir_set_mask(ir, IR_DEC_REG1, REG1_ENABLE, 0);
+	spin_unlock_irqrestore(&ir->lock, flags);
+
+	rc_unregister_device(ir->rc);
+
+	return 0;
+}
+
+static const struct of_device_id meson_ir_match[] = {
+	{ .compatible = "amlogic,meson6-ir" },
+	{ },
+};
+
+static struct platform_driver meson_ir_driver = {
+	.probe		= meson_ir_probe,
+	.remove		= meson_ir_remove,
+	.driver = {
+		.name		= DRIVER_NAME,
+		.of_match_table	= meson_ir_match,
+	},
+};
+
+module_platform_driver(meson_ir_driver);
+
+MODULE_DESCRIPTION("Amlogic Meson IR remote receiver driver");
+MODULE_AUTHOR("Beniamino Galvani <b.galvani@xxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
-- 
1.9.1

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