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Subject[PATCH v5] media: st-rc: Add ST remote control driver
Date
From: Srinivas Kandagatla <srinivas.kandagatla@st.com>

This patch adds support to ST RC driver, which is basically a IR/UHF
receiver and transmitter. This IP (IRB) is common across all the ST
parts for settop box platforms. IRB is embedded in ST COMMS IP block.
It supports both Rx & Tx functionality.

This driver adds only Rx functionality via LIRC codec.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Acked-by: Sean Young <sean@mess.org>
---
Hi Chehab,

This is a very simple rc driver for IRB controller found in STi SOCs.
This driver is a raw driver which feeds data to lirc codec for the user lircd
to decode the keys.

This patch is based on v3.12-rc1.

Changes since v4:
- updated dt bindings doc with suggestions from Stephen W.

Changes since v3:
- updated dt bindings doc with suggestions from Mark R.

Changes since v2:
- Updated Kconfig dependencies as suggested by Sean and Chehab.
- Fixed a logical check spoted by Sean.

Changes since v1:
- Device tree bindings cleaned up as suggested by Mark and Pawel
- use ir_raw_event_reset under overflow conditions as suggested by Sean.
- call ir_raw_event_handle in interrupt handler as suggested by Sean.
- correct allowed_protos flag with RC_BIT_ types as suggested by Sean.
- timeout and rx resolution added as suggested by Sean.

Thankyou all for reviewing and commenting.

Thanks,
srini
Documentation/devicetree/bindings/media/st-rc.txt | 27 ++
drivers/media/rc/Kconfig | 10 +
drivers/media/rc/Makefile | 1 +
drivers/media/rc/st_rc.c | 396 +++++++++++++++++++++
4 files changed, 434 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/media/st-rc.txt
create mode 100644 drivers/media/rc/st_rc.c

diff --git a/Documentation/devicetree/bindings/media/st-rc.txt b/Documentation/devicetree/bindings/media/st-rc.txt
new file mode 100644
index 0000000..797ef39
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/st-rc.txt
@@ -0,0 +1,27 @@
+Device-Tree bindings for ST IRB IP
+
+Required properties:
+ - compatible: Should contain "st,comms-irb".
+ - reg: Base physical address of the controller and length of memory
+ mapped region.
+ - interrupts: interrupt-specifier for the sole interrupt generated by
+ the device. The interrupt specifier format depends on the interrupt
+ controller parent.
+ - rx-mode: can be "infrared" or "uhf". rx-mode should be present iff
+ the rx pins are wired up.
+ - tx-mode: should be "infrared". tx-mode should be present iff the tx
+ pins are wired up.
+
+Optional properties:
+ - pinctrl-names, pinctrl-0: the pincontrol settings to configure muxing
+ properly for IRB pins.
+ - clocks : phandle with clock-specifier pair for IRB block.
+
+Example node:
+
+ rc: rc@fe518000 {
+ compatible = "st,comms-irb";
+ reg = <0xfe518000 0x234>;
+ interrupts = <0 203 0>;
+ rx-mode = "infrared";
+ };
diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig
index 11e84bc..557afc5 100644
--- a/drivers/media/rc/Kconfig
+++ b/drivers/media/rc/Kconfig
@@ -322,4 +322,14 @@ config IR_GPIO_CIR
To compile this driver as a module, choose M here: the module will
be called gpio-ir-recv.

+config RC_ST
+ tristate "ST remote control receiver"
+ depends on ARCH_STI && RC_CORE
+ help
+ Say Y here if you want support for ST remote control driver
+ which allows both IR and UHF RX.
+ The driver passes raw pluse and space information to the LIRC decoder.
+
+ If you're not sure, select N here.
+
endif #RC_DEVICES
diff --git a/drivers/media/rc/Makefile b/drivers/media/rc/Makefile
index 56bacf0..f4eb32c 100644
--- a/drivers/media/rc/Makefile
+++ b/drivers/media/rc/Makefile
@@ -30,3 +30,4 @@ obj-$(CONFIG_RC_LOOPBACK) += rc-loopback.o
obj-$(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
diff --git a/drivers/media/rc/st_rc.c b/drivers/media/rc/st_rc.c
new file mode 100644
index 0000000..e2dad9c
--- /dev/null
+++ b/drivers/media/rc/st_rc.c
@@ -0,0 +1,396 @@
+/*
+ * Copyright (C) 2013 STMicroelectronics Limited
+ * Author: Srinivas Kandagatla <srinivas.kandagatla@st.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.
+ */
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <media/rc-core.h>
+#include <linux/pinctrl/consumer.h>
+
+struct st_rc_device {
+ struct device *dev;
+ int irq;
+ int irq_wake;
+ struct clk *sys_clock;
+ void *base; /* Register base address */
+ void *rx_base;/* RX Register base address */
+ struct rc_dev *rdev;
+ bool overclocking;
+ int sample_mult;
+ int sample_div;
+ bool rxuhfmode;
+};
+
+/* Registers */
+#define IRB_SAMPLE_RATE_COMM 0x64 /* sample freq divisor*/
+#define IRB_CLOCK_SEL 0x70 /* clock select */
+#define IRB_CLOCK_SEL_STATUS 0x74 /* clock status */
+/* IRB IR/UHF receiver registers */
+#define IRB_RX_ON 0x40 /* pulse time capture */
+#define IRB_RX_SYS 0X44 /* sym period capture */
+#define IRB_RX_INT_EN 0x48 /* IRQ enable (R/W) */
+#define IRB_RX_INT_STATUS 0x4C /* IRQ status (R/W) */
+#define IRB_RX_EN 0x50 /* Receive enablei */
+#define IRB_MAX_SYM_PERIOD 0x54 /* max sym value */
+#define IRB_RX_INT_CLEAR 0x58 /* overrun status */
+#define IRB_RX_STATUS 0x6C /* receive status */
+#define IRB_RX_NOISE_SUPPR 0x5C /* noise suppression */
+#define IRB_RX_POLARITY_INV 0x68 /* polarity inverter */
+
+/**
+ * IRQ set: Enable full FIFO 1 -> bit 3;
+ * Enable overrun IRQ 1 -> bit 2;
+ * Enable last symbol IRQ 1 -> bit 1:
+ * Enable RX interrupt 1 -> bit 0;
+ */
+#define IRB_RX_INTS 0x0f
+#define IRB_RX_OVERRUN_INT 0x04
+ /* maximum symbol period (microsecs),timeout to detect end of symbol train */
+#define MAX_SYMB_TIME 0x5000
+#define IRB_SAMPLE_FREQ 10000000
+#define IRB_FIFO_NOT_EMPTY 0xff00
+#define IRB_OVERFLOW 0x4
+#define IRB_TIMEOUT 0xffff
+#define IR_ST_NAME "st-rc"
+
+static void st_rc_send_lirc_timeout(struct rc_dev *rdev)
+{
+ DEFINE_IR_RAW_EVENT(ev);
+ ev.timeout = true;
+ ir_raw_event_store(rdev, &ev);
+}
+
+/**
+ * RX graphical example to better understand the difference between ST IR block
+ * output and standard definition used by LIRC (and most of the world!)
+ *
+ * mark mark
+ * |-IRB_RX_ON-| |-IRB_RX_ON-|
+ * ___ ___ ___ ___ ___ ___ _
+ * | | | | | | | | | | | | |
+ * | | | | | | space 0 | | | | | | space 1 |
+ * _____| |__| |__| |____________________________| |__| |__| |_____________|
+ *
+ * |--------------- IRB_RX_SYS -------------|------ IRB_RX_SYS -------|
+ *
+ * |------------- encoding bit 0 -----------|---- encoding bit 1 -----|
+ *
+ * ST hardware returns mark (IRB_RX_ON) and total symbol time (IRB_RX_SYS), so
+ * convert to standard mark/space we have to calculate space=(IRB_RX_SYS-mark)
+ * The mark time represents the amount of time the carrier (usually 36-40kHz)
+ * is detected.The above examples shows Pulse Width Modulation encoding where
+ * bit 0 is represented by space>mark.
+ */
+
+static irqreturn_t st_rc_rx_interrupt(int irq, void *data)
+{
+ unsigned int symbol, mark = 0;
+ struct st_rc_device *dev = data;
+ int last_symbol = 0;
+ u32 status;
+ DEFINE_IR_RAW_EVENT(ev);
+
+ if (dev->irq_wake)
+ pm_wakeup_event(dev->dev, 0);
+
+ status = readl(dev->rx_base + IRB_RX_STATUS);
+
+ while (status & (IRB_FIFO_NOT_EMPTY | IRB_OVERFLOW)) {
+ u32 int_status = readl(dev->rx_base + IRB_RX_INT_STATUS);
+ if (unlikely(int_status & IRB_RX_OVERRUN_INT)) {
+ /* discard the entire collection in case of errors! */
+ ir_raw_event_reset(dev->rdev);
+ dev_info(dev->dev, "IR RX overrun\n");
+ writel(IRB_RX_OVERRUN_INT,
+ dev->rx_base + IRB_RX_INT_CLEAR);
+ continue;
+ }
+
+ symbol = readl(dev->rx_base + IRB_RX_SYS);
+ mark = readl(dev->rx_base + IRB_RX_ON);
+
+ if (symbol == IRB_TIMEOUT)
+ last_symbol = 1;
+
+ /* Ignore any noise */
+ if ((mark > 2) && (symbol > 1)) {
+ symbol -= mark;
+ if (dev->overclocking) { /* adjustments to timings */
+ symbol *= dev->sample_mult;
+ symbol /= dev->sample_div;
+ mark *= dev->sample_mult;
+ mark /= dev->sample_div;
+ }
+
+ ev.duration = US_TO_NS(mark);
+ ev.pulse = true;
+ ir_raw_event_store(dev->rdev, &ev);
+
+ if (!last_symbol) {
+ ev.duration = US_TO_NS(symbol);
+ ev.pulse = false;
+ ir_raw_event_store(dev->rdev, &ev);
+ } else {
+ st_rc_send_lirc_timeout(dev->rdev);
+ }
+
+ }
+ last_symbol = 0;
+ status = readl(dev->rx_base + IRB_RX_STATUS);
+ }
+
+ writel(IRB_RX_INTS, dev->rx_base + IRB_RX_INT_CLEAR);
+
+ /* Empty software fifo */
+ ir_raw_event_handle(dev->rdev);
+ return IRQ_HANDLED;
+}
+
+static void st_rc_hardware_init(struct st_rc_device *dev)
+{
+ int baseclock, freqdiff;
+ unsigned int rx_max_symbol_per = MAX_SYMB_TIME;
+ unsigned int rx_sampling_freq_div;
+
+ clk_prepare_enable(dev->sys_clock);
+ baseclock = clk_get_rate(dev->sys_clock);
+
+ /* IRB input pins are inverted internally from high to low. */
+ writel(1, dev->rx_base + IRB_RX_POLARITY_INV);
+
+ rx_sampling_freq_div = baseclock / IRB_SAMPLE_FREQ;
+ writel(rx_sampling_freq_div, dev->base + IRB_SAMPLE_RATE_COMM);
+
+ freqdiff = baseclock - (rx_sampling_freq_div * IRB_SAMPLE_FREQ);
+ if (freqdiff) { /* over clocking, workout the adjustment factors */
+ dev->overclocking = true;
+ dev->sample_mult = 1000;
+ dev->sample_div = baseclock / (10000 * rx_sampling_freq_div);
+ rx_max_symbol_per = (rx_max_symbol_per * 1000)/dev->sample_div;
+ }
+
+ writel(rx_max_symbol_per, dev->rx_base + IRB_MAX_SYM_PERIOD);
+}
+
+static int st_rc_remove(struct platform_device *pdev)
+{
+ struct st_rc_device *rc_dev = platform_get_drvdata(pdev);
+ clk_disable_unprepare(rc_dev->sys_clock);
+ rc_unregister_device(rc_dev->rdev);
+ return 0;
+}
+
+static int st_rc_open(struct rc_dev *rdev)
+{
+ struct st_rc_device *dev = rdev->priv;
+ unsigned long flags;
+ local_irq_save(flags);
+ /* enable interrupts and receiver */
+ writel(IRB_RX_INTS, dev->rx_base + IRB_RX_INT_EN);
+ writel(0x01, dev->rx_base + IRB_RX_EN);
+ local_irq_restore(flags);
+
+ return 0;
+}
+
+static void st_rc_close(struct rc_dev *rdev)
+{
+ struct st_rc_device *dev = rdev->priv;
+ /* disable interrupts and receiver */
+ writel(0x00, dev->rx_base + IRB_RX_EN);
+ writel(0x00, dev->rx_base + IRB_RX_INT_EN);
+}
+
+static int st_rc_probe(struct platform_device *pdev)
+{
+ int ret = -EINVAL;
+ struct rc_dev *rdev;
+ struct device *dev = &pdev->dev;
+ struct resource *res;
+ struct st_rc_device *rc_dev;
+ struct device_node *np = pdev->dev.of_node;
+ const char *rx_mode;
+
+ rc_dev = devm_kzalloc(dev, sizeof(struct st_rc_device), GFP_KERNEL);
+
+ if (!rc_dev)
+ return -ENOMEM;
+
+ rdev = rc_allocate_device();
+
+ if (!rdev)
+ return -ENOMEM;
+
+ if (np && !of_property_read_string(np, "rx-mode", &rx_mode)) {
+
+ if (!strcmp(rx_mode, "uhf")) {
+ rc_dev->rxuhfmode = true;
+ } else if (!strcmp(rx_mode, "infrared")) {
+ rc_dev->rxuhfmode = false;
+ } else {
+ dev_err(dev, "Unsupported rx mode [%s]\n", rx_mode);
+ goto err;
+ }
+
+ } else {
+ goto err;
+ }
+
+ rc_dev->sys_clock = devm_clk_get(dev, NULL);
+ if (IS_ERR(rc_dev->sys_clock)) {
+ dev_err(dev, "System clock not found\n");
+ ret = PTR_ERR(rc_dev->sys_clock);
+ goto err;
+ }
+
+ rc_dev->irq = platform_get_irq(pdev, 0);
+ if (rc_dev->irq < 0) {
+ ret = rc_dev->irq;
+ goto clkerr;
+ }
+
+ ret = -ENODEV;
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ goto clkerr;
+
+ rc_dev->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(rc_dev->base))
+ goto clkerr;
+
+ if (rc_dev->rxuhfmode)
+ rc_dev->rx_base = rc_dev->base + 0x40;
+ else
+ rc_dev->rx_base = rc_dev->base;
+
+ rc_dev->dev = dev;
+ platform_set_drvdata(pdev, rc_dev);
+ st_rc_hardware_init(rc_dev);
+
+ rdev->driver_type = RC_DRIVER_IR_RAW;
+ rdev->allowed_protos = RC_BIT_ALL;
+ /* rx sampling rate is 10Mhz */
+ rdev->rx_resolution = 100;
+ rdev->timeout = US_TO_NS(MAX_SYMB_TIME);
+ rdev->priv = rc_dev;
+ rdev->open = st_rc_open;
+ rdev->close = st_rc_close;
+ rdev->driver_name = IR_ST_NAME;
+ rdev->map_name = RC_MAP_LIRC;
+ rdev->input_name = "ST Remote Control Receiver";
+
+ /* enable wake via this device */
+ device_set_wakeup_capable(dev, true);
+ device_set_wakeup_enable(dev, true);
+
+ ret = rc_register_device(rdev);
+ if (ret < 0)
+ goto clkerr;
+
+ rc_dev->rdev = rdev;
+ if (devm_request_irq(dev, rc_dev->irq, st_rc_rx_interrupt,
+ IRQF_NO_SUSPEND, IR_ST_NAME, rc_dev) < 0) {
+ dev_err(dev, "IRQ %d register failed\n", rc_dev->irq);
+ ret = -EINVAL;
+ goto rcerr;
+ }
+
+ /**
+ * for LIRC_MODE_MODE2 or LIRC_MODE_PULSE or LIRC_MODE_RAW
+ * lircd expects a long space first before a signal train to sync.
+ */
+ st_rc_send_lirc_timeout(rdev);
+
+ dev_info(dev, "setup in %s mode\n", rc_dev->rxuhfmode ? "UHF" : "IR");
+
+ return ret;
+rcerr:
+ rc_unregister_device(rdev);
+ rdev = NULL;
+clkerr:
+ clk_disable_unprepare(rc_dev->sys_clock);
+err:
+ rc_free_device(rdev);
+ dev_err(dev, "Unable to register device (%d)\n", ret);
+ return ret;
+}
+
+#ifdef CONFIG_PM
+static int st_rc_suspend(struct device *dev)
+{
+ struct st_rc_device *rc_dev = dev_get_drvdata(dev);
+
+ if (device_may_wakeup(dev)) {
+ if (!enable_irq_wake(rc_dev->irq))
+ rc_dev->irq_wake = 1;
+ else
+ return -EINVAL;
+ } else {
+ pinctrl_pm_select_sleep_state(dev);
+ writel(0x00, rc_dev->rx_base + IRB_RX_EN);
+ writel(0x00, rc_dev->rx_base + IRB_RX_INT_EN);
+ clk_disable_unprepare(rc_dev->sys_clock);
+ }
+
+ return 0;
+}
+
+static int st_rc_resume(struct device *dev)
+{
+ struct st_rc_device *rc_dev = dev_get_drvdata(dev);
+ struct rc_dev *rdev = rc_dev->rdev;
+
+ if (rc_dev->irq_wake) {
+ disable_irq_wake(rc_dev->irq);
+ rc_dev->irq_wake = 0;
+ } else {
+ pinctrl_pm_select_default_state(dev);
+ st_rc_hardware_init(rc_dev);
+ if (rdev->users) {
+ writel(IRB_RX_INTS, rc_dev->rx_base + IRB_RX_INT_EN);
+ writel(0x01, rc_dev->rx_base + IRB_RX_EN);
+ }
+ }
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(st_rc_pm_ops, st_rc_suspend, st_rc_resume);
+#endif
+
+#ifdef CONFIG_OF
+static struct of_device_id st_rc_match[] = {
+ { .compatible = "st,comms-irb", },
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, st_rc_match);
+#endif
+
+static struct platform_driver st_rc_driver = {
+ .driver = {
+ .name = IR_ST_NAME,
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(st_rc_match),
+#ifdef CONFIG_PM
+ .pm = &st_rc_pm_ops,
+#endif
+ },
+ .probe = st_rc_probe,
+ .remove = st_rc_remove,
+};
+
+module_platform_driver(st_rc_driver);
+
+MODULE_DESCRIPTION("RC Transceiver driver for STMicroelectronics platforms");
+MODULE_AUTHOR("STMicroelectronics (R&D) Ltd");
+MODULE_LICENSE("GPL");
--
1.7.6.5


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