Re: [PATCH v2 2/3] media: rc: add driver for Amlogic Meson IR remote receiver

[Sean Young]

On Sun, Nov 09, 2014 at 09:32:07AM +0100, Beniamino Galvani wrote:
> Amlogic Meson SoCs include a infrared remote control receiver that can
> operate in two modes: "NEC" mode in which the hardware decodes frames
> using the NEC IR protocol, and "general" mode in which the receiver
> simply reports the duration of pulses and spaces for software
> decoding.
> 
> This is a driver for the IR receiver that implements software decoding
> of received frames.
> 
> Signed-off-by: Beniamino Galvani <b.galvani@xxxxxxxxx>
> ---
>  MAINTAINERS                 |   1 +
>  drivers/media/rc/Kconfig    |  11 +++
>  drivers/media/rc/Makefile   |   1 +
>  drivers/media/rc/meson-ir.c | 215 ++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 228 insertions(+)
>  create mode 100644 drivers/media/rc/meson-ir.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 0662378..f1bc045 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -850,6 +850,7 @@ ARM/Amlogic MesonX SoC support
>  M:	Carlo Caione <carlo@xxxxxxxxxx>
>  L:	linux-arm-kernel@xxxxxxxxxxxxxxxxxxx (moderated for non-subscribers)
>  S:	Maintained
> +F:	drivers/media/rc/meson-ir.c
>  N:	meson[x68]
>  
>  ARM/ATMEL AT91RM9200 AND AT91SAM ARM ARCHITECTURES
> diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig
> index 1aea732..ddfab25 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 || COMPILE_TEST
> +	---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 8f509e0..379a5c0 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..4d6aed1
> --- /dev/null
> +++ b/drivers/media/rc/meson-ir.c
> @@ -0,0 +1,215 @@
> +/*
> + * 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/device.h>
> +#include <linux/err.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.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;
> +	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);

rc_unregister_device() already calls rc_free_device().

> +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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