--- /dev/null
+// 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");
projects / thirdparty / kernel / linux.git / commitdiff
