media: rc: introduce Meson IR TX driver

This patch adds the driver for Amlogic Meson IR transmitter.

Some Amlogic SoCs such as A311D and T950D4 have IR transmitter
(also called blaster) controller onboard. It is capable of sending
IR signals with arbitrary carrier frequency and duty cycle.

The driver supports 2 modulation clock sources:
 - xtal3 clock (xtal divided by 3)
 - 1us clock

Signed-off-by: Viktor Prutyanov <viktor.prutyanov@phystech.edu>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This commit is contained in:
Viktor Prutyanov 2021-07-19 19:05:06 +02:00 committed by Mauro Carvalho Chehab
parent e9f504f7b5
commit 49be1c78d5
3 changed files with 418 additions and 0 deletions

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@ -246,6 +246,16 @@ config IR_MESON
To compile this driver as a module, choose M here: the
module will be called meson-ir.
config IR_MESON_TX
tristate "Amlogic Meson IR TX"
depends on ARCH_MESON || COMPILE_TEST
help
Say Y if you want to use the IR transmitter available on
Amlogic Meson SoCs.
To compile this driver as a module, choose M here: the
module will be called meson-ir-tx.
config IR_MTK
tristate "Mediatek IR remote receiver"
depends on ARCH_MEDIATEK || COMPILE_TEST

View File

@ -28,6 +28,7 @@ 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-$(CONFIG_IR_MESON_TX) += meson-ir-tx.o
obj-$(CONFIG_IR_NUVOTON) += nuvoton-cir.o
obj-$(CONFIG_IR_ENE) += ene_ir.o
obj-$(CONFIG_IR_REDRAT3) += redrat3.o

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@ -0,0 +1,407 @@
// 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) {
dev_err(dev, "no irq resource found\n");
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,
.owner = THIS_MODULE,
.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");