diff options
Diffstat (limited to 'drivers/media/rc/meson-ir-tx.c')
| -rw-r--r-- | drivers/media/rc/meson-ir-tx.c | 404 |
1 files changed, 404 insertions, 0 deletions
diff --git a/drivers/media/rc/meson-ir-tx.c b/drivers/media/rc/meson-ir-tx.c new file mode 100644 index 000000000..abdb62b16 --- /dev/null +++ b/drivers/media/rc/meson-ir-tx.c @@ -0,0 +1,404 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * meson-ir-tx.c - Amlogic Meson IR TX driver + * + * Copyright (c) 2021, SberDevices. All Rights Reserved. + * + * Author: Viktor Prutyanov <viktor.prutyanov@phystech.edu> + */ + +#include <linux/device.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/platform_device.h> +#include <linux/of.h> +#include <linux/interrupt.h> +#include <linux/spinlock.h> +#include <linux/of_irq.h> +#include <linux/clk.h> +#include <linux/slab.h> +#include <media/rc-core.h> + +#define DEVICE_NAME "Meson IR TX" +#define DRIVER_NAME "meson-ir-tx" + +#define MIRTX_DEFAULT_CARRIER 38000 +#define MIRTX_DEFAULT_DUTY_CYCLE 50 +#define MIRTX_FIFO_THD 32 + +#define IRB_MOD_1US_CLK_RATE 1000000 + +#define IRB_FIFO_LEN 128 + +#define IRB_ADDR0 0x0 +#define IRB_ADDR1 0x4 +#define IRB_ADDR2 0x8 +#define IRB_ADDR3 0xc + +#define IRB_MAX_DELAY (1 << 10) +#define IRB_DELAY_MASK (IRB_MAX_DELAY - 1) + +/* IRCTRL_IR_BLASTER_ADDR0 */ +#define IRB_MOD_CLK(x) ((x) << 12) +#define IRB_MOD_SYS_CLK 0 +#define IRB_MOD_XTAL3_CLK 1 +#define IRB_MOD_1US_CLK 2 +#define IRB_MOD_10US_CLK 3 +#define IRB_INIT_HIGH BIT(2) +#define IRB_ENABLE BIT(0) + +/* IRCTRL_IR_BLASTER_ADDR2 */ +#define IRB_MOD_COUNT(lo, hi) ((((lo) - 1) << 16) | ((hi) - 1)) + +/* IRCTRL_IR_BLASTER_ADDR2 */ +#define IRB_WRITE_FIFO BIT(16) +#define IRB_MOD_ENABLE BIT(12) +#define IRB_TB_1US (0x0 << 10) +#define IRB_TB_10US (0x1 << 10) +#define IRB_TB_100US (0x2 << 10) +#define IRB_TB_MOD_CLK (0x3 << 10) + +/* IRCTRL_IR_BLASTER_ADDR3 */ +#define IRB_FIFO_THD_PENDING BIT(16) +#define IRB_FIFO_IRQ_ENABLE BIT(8) + +struct meson_irtx { + struct device *dev; + void __iomem *reg_base; + u32 *buf; + unsigned int buf_len; + unsigned int buf_head; + unsigned int carrier; + unsigned int duty_cycle; + /* Locks buf */ + spinlock_t lock; + struct completion completion; + unsigned long clk_rate; +}; + +static void meson_irtx_set_mod(struct meson_irtx *ir) +{ + unsigned int cnt = DIV_ROUND_CLOSEST(ir->clk_rate, ir->carrier); + unsigned int pulse_cnt = DIV_ROUND_CLOSEST(cnt * ir->duty_cycle, 100); + unsigned int space_cnt = cnt - pulse_cnt; + + dev_dbg(ir->dev, "F_mod = %uHz, T_mod = %luns, duty_cycle = %u%%\n", + ir->carrier, NSEC_PER_SEC / ir->clk_rate * cnt, + 100 * pulse_cnt / cnt); + + writel(IRB_MOD_COUNT(pulse_cnt, space_cnt), + ir->reg_base + IRB_ADDR1); +} + +static void meson_irtx_setup(struct meson_irtx *ir, unsigned int clk_nr) +{ + /* + * Disable the TX, set modulator clock tick and set initialize + * output to be high. Set up carrier frequency and duty cycle. Then + * unset initialize output. Enable FIFO interrupt, set FIFO interrupt + * threshold. Finally, enable the transmitter back. + */ + writel(~IRB_ENABLE & (IRB_MOD_CLK(clk_nr) | IRB_INIT_HIGH), + ir->reg_base + IRB_ADDR0); + meson_irtx_set_mod(ir); + writel(readl(ir->reg_base + IRB_ADDR0) & ~IRB_INIT_HIGH, + ir->reg_base + IRB_ADDR0); + writel(IRB_FIFO_IRQ_ENABLE | MIRTX_FIFO_THD, + ir->reg_base + IRB_ADDR3); + writel(readl(ir->reg_base + IRB_ADDR0) | IRB_ENABLE, + ir->reg_base + IRB_ADDR0); +} + +static u32 meson_irtx_prepare_pulse(struct meson_irtx *ir, unsigned int time) +{ + unsigned int delay; + unsigned int tb = IRB_TB_MOD_CLK; + unsigned int tb_us = DIV_ROUND_CLOSEST(USEC_PER_SEC, ir->carrier); + + delay = (DIV_ROUND_CLOSEST(time, tb_us) - 1) & IRB_DELAY_MASK; + + return ((IRB_WRITE_FIFO | IRB_MOD_ENABLE) | tb | delay); +} + +static u32 meson_irtx_prepare_space(struct meson_irtx *ir, unsigned int time) +{ + unsigned int delay; + unsigned int tb = IRB_TB_100US; + unsigned int tb_us = 100; + + if (time <= IRB_MAX_DELAY) { + tb = IRB_TB_1US; + tb_us = 1; + } else if (time <= 10 * IRB_MAX_DELAY) { + tb = IRB_TB_10US; + tb_us = 10; + } else if (time <= 100 * IRB_MAX_DELAY) { + tb = IRB_TB_100US; + tb_us = 100; + } + + delay = (DIV_ROUND_CLOSEST(time, tb_us) - 1) & IRB_DELAY_MASK; + + return ((IRB_WRITE_FIFO & ~IRB_MOD_ENABLE) | tb | delay); +} + +static void meson_irtx_send_buffer(struct meson_irtx *ir) +{ + unsigned int nr = 0; + unsigned int max_fifo_level = IRB_FIFO_LEN - MIRTX_FIFO_THD; + + while (ir->buf_head < ir->buf_len && nr < max_fifo_level) { + writel(ir->buf[ir->buf_head], ir->reg_base + IRB_ADDR2); + + ir->buf_head++; + nr++; + } +} + +static bool meson_irtx_check_buf(struct meson_irtx *ir, + unsigned int *buf, unsigned int len) +{ + unsigned int i; + + for (i = 0; i < len; i++) { + unsigned int max_tb_us; + /* + * Max space timebase is 100 us. + * Pulse timebase equals to carrier period. + */ + if (i % 2 == 0) + max_tb_us = USEC_PER_SEC / ir->carrier; + else + max_tb_us = 100; + + if (buf[i] >= max_tb_us * IRB_MAX_DELAY) + return false; + } + + return true; +} + +static void meson_irtx_fill_buf(struct meson_irtx *ir, u32 *dst_buf, + unsigned int *src_buf, unsigned int len) +{ + unsigned int i; + + for (i = 0; i < len; i++) { + if (i % 2 == 0) + dst_buf[i] = meson_irtx_prepare_pulse(ir, src_buf[i]); + else + dst_buf[i] = meson_irtx_prepare_space(ir, src_buf[i]); + } +} + +static irqreturn_t meson_irtx_irqhandler(int irq, void *data) +{ + unsigned long flags; + struct meson_irtx *ir = data; + + writel(readl(ir->reg_base + IRB_ADDR3) & ~IRB_FIFO_THD_PENDING, + ir->reg_base + IRB_ADDR3); + + if (completion_done(&ir->completion)) + return IRQ_HANDLED; + + spin_lock_irqsave(&ir->lock, flags); + if (ir->buf_head < ir->buf_len) + meson_irtx_send_buffer(ir); + else + complete(&ir->completion); + spin_unlock_irqrestore(&ir->lock, flags); + + return IRQ_HANDLED; +} + +static int meson_irtx_set_carrier(struct rc_dev *rc, u32 carrier) +{ + struct meson_irtx *ir = rc->priv; + + if (carrier == 0) + return -EINVAL; + + ir->carrier = carrier; + meson_irtx_set_mod(ir); + + return 0; +} + +static int meson_irtx_set_duty_cycle(struct rc_dev *rc, u32 duty_cycle) +{ + struct meson_irtx *ir = rc->priv; + + ir->duty_cycle = duty_cycle; + meson_irtx_set_mod(ir); + + return 0; +} + +static void meson_irtx_update_buf(struct meson_irtx *ir, u32 *buf, + unsigned int len, unsigned int head) +{ + ir->buf = buf; + ir->buf_len = len; + ir->buf_head = head; +} + +static int meson_irtx_transmit(struct rc_dev *rc, unsigned int *buf, + unsigned int len) +{ + unsigned long flags; + struct meson_irtx *ir = rc->priv; + u32 *tx_buf; + int ret = len; + + if (!meson_irtx_check_buf(ir, buf, len)) + return -EINVAL; + + tx_buf = kmalloc_array(len, sizeof(u32), GFP_KERNEL); + if (!tx_buf) + return -ENOMEM; + + meson_irtx_fill_buf(ir, tx_buf, buf, len); + dev_dbg(ir->dev, "TX buffer filled, length = %u\n", len); + + spin_lock_irqsave(&ir->lock, flags); + meson_irtx_update_buf(ir, tx_buf, len, 0); + reinit_completion(&ir->completion); + meson_irtx_send_buffer(ir); + spin_unlock_irqrestore(&ir->lock, flags); + + if (!wait_for_completion_timeout(&ir->completion, + usecs_to_jiffies(IR_MAX_DURATION))) + ret = -ETIMEDOUT; + + spin_lock_irqsave(&ir->lock, flags); + kfree(ir->buf); + meson_irtx_update_buf(ir, NULL, 0, 0); + spin_unlock_irqrestore(&ir->lock, flags); + + return ret; +} + +static int meson_irtx_mod_clock_probe(struct meson_irtx *ir, + unsigned int *clk_nr) +{ + struct device_node *np = ir->dev->of_node; + struct clk *clock; + + if (!np) + return -ENODEV; + + clock = devm_clk_get(ir->dev, "xtal"); + if (IS_ERR(clock) || clk_prepare_enable(clock)) + return -ENODEV; + + *clk_nr = IRB_MOD_XTAL3_CLK; + ir->clk_rate = clk_get_rate(clock) / 3; + + if (ir->clk_rate < IRB_MOD_1US_CLK_RATE) { + *clk_nr = IRB_MOD_1US_CLK; + ir->clk_rate = IRB_MOD_1US_CLK_RATE; + } + + dev_info(ir->dev, "F_clk = %luHz\n", ir->clk_rate); + + return 0; +} + +static int __init meson_irtx_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct meson_irtx *ir; + struct rc_dev *rc; + int irq; + unsigned int clk_nr; + int ret; + + ir = devm_kzalloc(dev, sizeof(*ir), GFP_KERNEL); + if (!ir) + return -ENOMEM; + + ir->reg_base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(ir->reg_base)) + return PTR_ERR(ir->reg_base); + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return -ENODEV; + + ir->dev = dev; + ir->carrier = MIRTX_DEFAULT_CARRIER; + ir->duty_cycle = MIRTX_DEFAULT_DUTY_CYCLE; + init_completion(&ir->completion); + spin_lock_init(&ir->lock); + + ret = meson_irtx_mod_clock_probe(ir, &clk_nr); + if (ret) { + dev_err(dev, "modulator clock setup failed\n"); + return ret; + } + meson_irtx_setup(ir, clk_nr); + + ret = devm_request_irq(dev, irq, + meson_irtx_irqhandler, + IRQF_TRIGGER_RISING, + DRIVER_NAME, ir); + if (ret) { + dev_err(dev, "irq request failed\n"); + return ret; + } + + rc = rc_allocate_device(RC_DRIVER_IR_RAW_TX); + if (!rc) + return -ENOMEM; + + rc->driver_name = DRIVER_NAME; + rc->device_name = DEVICE_NAME; + rc->priv = ir; + + rc->tx_ir = meson_irtx_transmit; + rc->s_tx_carrier = meson_irtx_set_carrier; + rc->s_tx_duty_cycle = meson_irtx_set_duty_cycle; + + ret = rc_register_device(rc); + if (ret < 0) { + dev_err(dev, "rc_dev registration failed\n"); + rc_free_device(rc); + return ret; + } + + platform_set_drvdata(pdev, rc); + + return 0; +} + +static int meson_irtx_remove(struct platform_device *pdev) +{ + struct rc_dev *rc = platform_get_drvdata(pdev); + + rc_unregister_device(rc); + + return 0; +} + +static const struct of_device_id meson_irtx_dt_match[] = { + { + .compatible = "amlogic,meson-g12a-ir-tx", + }, + {}, +}; +MODULE_DEVICE_TABLE(of, meson_irtx_dt_match); + +static struct platform_driver meson_irtx_pd = { + .remove = meson_irtx_remove, + .driver = { + .name = DRIVER_NAME, + .of_match_table = meson_irtx_dt_match, + }, +}; + +module_platform_driver_probe(meson_irtx_pd, meson_irtx_probe); + +MODULE_DESCRIPTION("Meson IR TX driver"); +MODULE_AUTHOR("Viktor Prutyanov <viktor.prutyanov@phystech.edu>"); +MODULE_LICENSE("GPL"); |