diff options
Diffstat (limited to 'drivers/media/rc/st_rc.c')
| -rw-r--r-- | drivers/media/rc/st_rc.c | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/drivers/media/rc/st_rc.c b/drivers/media/rc/st_rc.c new file mode 100644 index 000000000000..65120c2d47ad --- /dev/null +++ b/drivers/media/rc/st_rc.c @@ -0,0 +1,395 @@ +/* + * 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 enable */ +#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 err; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + + rc_dev->base = devm_ioremap_resource(dev, res); + if (IS_ERR(rc_dev->base)) { + ret = PTR_ERR(rc_dev->base); + goto err; + } + + 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"); |