Hi,
this is a driver for the IR transmitter (also called IR blaster)
available in some Amlogic Meson SoCs.
Viktor Prutyanov (2):
media: rc: meson-ir-tx: document device tree bindings
media: rc: introduce Meson IR TX driver
.../bindings/media/amlogic,meson-ir-tx.yaml | 65 +++
drivers/media/rc/Kconfig | 10 +
drivers/media/rc/Makefile | 1 +
drivers/media/rc/meson-ir-tx.c | 404 ++++++++++++++++++
4 files changed, 480 insertions(+)
create mode 100644 Documentation/devicetree/bindings/media/amlogic,meson-ir-tx.yaml
create mode 100644 drivers/media/rc/meson-ir-tx.c
--
2.21.0
This patch adds binding documentation for the IR transmitter
available in Amlogic Meson SoCs.
Signed-off-by: Viktor Prutyanov <[email protected]>
---
changes in v2:
- compatible = "amlogic,meson-g12a-irblaster" added
- clocks, clock-names and mod-clock updated
changes in v3:
- mod-clock removed
- max-fifo-level added
changes in v4:
- irblaster -> ir-tx renaming
.../bindings/media/amlogic,meson-ir-tx.yaml | 65 +++++++++++++++++++
1 file changed, 65 insertions(+)
create mode 100644 Documentation/devicetree/bindings/media/amlogic,meson-ir-tx.yaml
diff --git a/Documentation/devicetree/bindings/media/amlogic,meson-ir-tx.yaml b/Documentation/devicetree/bindings/media/amlogic,meson-ir-tx.yaml
new file mode 100644
index 000000000000..f9f20e30be2f
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/amlogic,meson-ir-tx.yaml
@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/media/amlogic,meson-ir-tx.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Amlogic Meson IR transmitter
+
+maintainers:
+ - Viktor Prutyanov <[email protected]>
+
+description: |
+ 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.
+
+properties:
+ compatible:
+ oneOf:
+ - const: amlogic,meson-ir-tx
+ - items:
+ - const: amlogic,meson-g12a-ir-tx
+ - const: amlogic,meson-ir-tx
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ maxItems: 1
+
+ clocks:
+ maxItems: 2
+
+ clock-names:
+ items:
+ - const: sysclk
+ - const: xtal
+
+ max-fifo-level:
+ maxItems: 1
+ description:
+ Maximum IR TX FIFO fill level
+
+required:
+ - compatible
+ - reg
+ - interrupts
+ - clocks
+ - clock-names
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/irq.h>
+ #include <dt-bindings/clock/g12a-clkc.h>
+
+ ir@ff80014c {
+ compatible = "amlogic,meson-g12a-ir-tx", "amlogic,meson-ir-tx";
+ reg = <0xff80014c 0x10>;
+ interrupts = <0 198 IRQ_TYPE_EDGE_RISING>;
+ clocks = <&clkc CLKID_CLK81>, <&xtal>;
+ clock-names = "sysclk", "xtal";
+ };
--
2.21.0
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 <[email protected]>
---
changes in v2:
- threaded IRQ removed, all stuff done in IRQ handler
- DIV_ROUND_CLOSEST_ULL replaced with DIV_ROUND_CLOSEST
- compatible changed to "amlogic,meson-g12a-irblaster"
- 'debug' parameter removed
- dprintk() replaced with dev_dbg()/dev_info()
- carrier frequency checked against 0
- device_name added
changes in v3:
- license header fixed
- 'max_fifo_level' parameter removed
- irq and clk_nr deleted from irblaster_dev struct
- some divisions replaced with DIV_ROUND_CLOSEST
- irb_send inlined
- fixed early completion in IRQ handler
- spin lock added before kfree
changes in v4:
- irblaster -> ir-tx renaming
- spin lock added before buffer allocation
drivers/media/rc/Kconfig | 10 +
drivers/media/rc/Makefile | 1 +
drivers/media/rc/meson-ir-tx.c | 404 +++++++++++++++++++++++++++++++++
3 files changed, 415 insertions(+)
create mode 100644 drivers/media/rc/meson-ir-tx.c
diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig
index d0a8326b75c2..fd5a7a058714 100644
--- a/drivers/media/rc/Kconfig
+++ b/drivers/media/rc/Kconfig
@@ -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
diff --git a/drivers/media/rc/Makefile b/drivers/media/rc/Makefile
index 692e9b6b203f..0db51fad27d6 100644
--- a/drivers/media/rc/Makefile
+++ b/drivers/media/rc/Makefile
@@ -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
diff --git a/drivers/media/rc/meson-ir-tx.c b/drivers/media/rc/meson-ir-tx.c
new file mode 100644
index 000000000000..b936a6962849
--- /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 <[email protected]>
+ */
+
+#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_DEFAULT_MAX_FIFO_LEVEL 96
+
+#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;
+ spinlock_t lock;
+ struct completion completion;
+ unsigned int max_fifo_level;
+ 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)
+{
+ unsigned int fifo_irq_threshold = IRB_FIFO_LEN - ir->max_fifo_level;
+
+ /*
+ * 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 | fifo_irq_threshold,
+ 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;
+
+ while (ir->buf_head < ir->buf_len && nr < ir->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, unsigned int *buf)
+{
+ unsigned int i;
+
+ for (i = 0; i < ir->buf_len; i++) {
+ if (i % 2 == 0)
+ ir->buf[i] = meson_irtx_prepare_pulse(ir, buf[i]);
+ else
+ ir->buf[i] = meson_irtx_prepare_space(ir, 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);
+
+ 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 int meson_irtx_transmit(struct rc_dev *rc, unsigned int *buf,
+ unsigned int len)
+{
+ unsigned long flags;
+ struct meson_irtx *ir = rc->priv;
+
+ if (!meson_irtx_check_buf(ir, buf, len))
+ return -EINVAL;
+
+ spin_lock_irqsave(&ir->lock, flags);
+ ir->buf = kmalloc_array(len, sizeof(u32), GFP_KERNEL);
+ if (!ir->buf)
+ return -ENOMEM;
+
+ ir->buf_len = len;
+ ir->buf_head = 0;
+ meson_irtx_fill_buf(ir, buf);
+ spin_unlock_irqrestore(&ir->lock, flags);
+
+ reinit_completion(&ir->completion);
+ dev_dbg(ir->dev, "tx started, buffer length = %u\n", ir->buf_len);
+
+ spin_lock_irqsave(&ir->lock, flags);
+ meson_irtx_send_buffer(ir);
+ spin_unlock_irqrestore(&ir->lock, flags);
+
+ wait_for_completion_interruptible(&ir->completion);
+ dev_dbg(ir->dev, "tx completed\n");
+
+ spin_lock_irqsave(&ir->lock, flags);
+ kfree(ir->buf);
+ ir->buf = NULL;
+ ir->buf_len = 0;
+ spin_unlock_irqrestore(&ir->lock, flags);
+
+ return len;
+}
+
+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;
+ }
+
+ if (of_property_read_u32(dev->of_node, "max-fifo-level",
+ &ir->max_fifo_level))
+ ir->max_fifo_level = MIRTX_DEFAULT_MAX_FIFO_LEVEL;
+ else if (ir->max_fifo_level > IRB_FIFO_LEN)
+ ir->max_fifo_level = MIRTX_DEFAULT_MAX_FIFO_LEVEL;
+ dev_dbg(dev, "max FIFO level set to %u\n", ir->max_fifo_level);
+
+ 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 <[email protected]>");
+MODULE_LICENSE("GPL");
--
2.21.0
Hi Viktor,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on linuxtv-media/master]
[also build test WARNING on v5.14-rc1 next-20210712]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Viktor-Prutyanov/media-rc-add-support-for-Amlogic-Meson-IR-blaster/20210713-041906
base: git://linuxtv.org/media_tree.git master
config: sh-allmodconfig (attached as .config)
compiler: sh4-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/0day-ci/linux/commit/f74878fc5e09af1a0ea3a7e0c37badd2d3d0963f
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Viktor-Prutyanov/media-rc-add-support-for-Amlogic-Meson-IR-blaster/20210713-041906
git checkout f74878fc5e09af1a0ea3a7e0c37badd2d3d0963f
# save the attached .config to linux build tree
mkdir build_dir
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross O=build_dir ARCH=sh SHELL=/bin/bash
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email protected]>
All warnings (new ones prefixed by >>):
>> drivers/media/rc/meson-ir-tx.c:22: warning: expecting prototype for meson(). Prototype was for DEVICE_NAME() instead
Kconfig warnings: (for reference only)
WARNING: unmet direct dependencies detected for SND_ATMEL_SOC_PDC
Depends on SOUND && !UML && SND && SND_SOC && SND_ATMEL_SOC && HAS_DMA
Selected by
- SND_ATMEL_SOC_SSC && SOUND && !UML && SND && SND_SOC && SND_ATMEL_SOC
- SND_ATMEL_SOC_SSC_PDC && SOUND && !UML && SND && SND_SOC && SND_ATMEL_SOC && ATMEL_SSC
vim +22 drivers/media/rc/meson-ir-tx.c
21
> 22 #define DEVICE_NAME "Meson IR TX"
23 #define DRIVER_NAME "meson-ir-tx"
24
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]
Hi Viktor,
On Mon, Jul 12, 2021 at 11:17:32PM +0300, Viktor Prutyanov wrote:
> 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 <[email protected]>
> ---
> changes in v2:
> - threaded IRQ removed, all stuff done in IRQ handler
> - DIV_ROUND_CLOSEST_ULL replaced with DIV_ROUND_CLOSEST
> - compatible changed to "amlogic,meson-g12a-irblaster"
> - 'debug' parameter removed
> - dprintk() replaced with dev_dbg()/dev_info()
> - carrier frequency checked against 0
> - device_name added
> changes in v3:
> - license header fixed
> - 'max_fifo_level' parameter removed
> - irq and clk_nr deleted from irblaster_dev struct
> - some divisions replaced with DIV_ROUND_CLOSEST
> - irb_send inlined
> - fixed early completion in IRQ handler
> - spin lock added before kfree
> changes in v4:
> - irblaster -> ir-tx renaming
> - spin lock added before buffer allocation
>
> drivers/media/rc/Kconfig | 10 +
> drivers/media/rc/Makefile | 1 +
> drivers/media/rc/meson-ir-tx.c | 404 +++++++++++++++++++++++++++++++++
> 3 files changed, 415 insertions(+)
> create mode 100644 drivers/media/rc/meson-ir-tx.c
>
> diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig
> index d0a8326b75c2..fd5a7a058714 100644
> --- a/drivers/media/rc/Kconfig
> +++ b/drivers/media/rc/Kconfig
> @@ -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
> diff --git a/drivers/media/rc/Makefile b/drivers/media/rc/Makefile
> index 692e9b6b203f..0db51fad27d6 100644
> --- a/drivers/media/rc/Makefile
> +++ b/drivers/media/rc/Makefile
> @@ -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
> diff --git a/drivers/media/rc/meson-ir-tx.c b/drivers/media/rc/meson-ir-tx.c
> new file mode 100644
> index 000000000000..b936a6962849
> --- /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 <[email protected]>
> + */
> +
> +#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_DEFAULT_MAX_FIFO_LEVEL 96
> +
> +#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;
> + spinlock_t lock;
> + struct completion completion;
> + unsigned int max_fifo_level;
> + 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)
> +{
> + unsigned int fifo_irq_threshold = IRB_FIFO_LEN - ir->max_fifo_level;
> +
> + /*
> + * 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 | fifo_irq_threshold,
> + 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;
> +
> + while (ir->buf_head < ir->buf_len && nr < ir->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, unsigned int *buf)
> +{
> + unsigned int i;
> +
> + for (i = 0; i < ir->buf_len; i++) {
> + if (i % 2 == 0)
> + ir->buf[i] = meson_irtx_prepare_pulse(ir, buf[i]);
> + else
> + ir->buf[i] = meson_irtx_prepare_space(ir, 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);
> +
> + 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 int meson_irtx_transmit(struct rc_dev *rc, unsigned int *buf,
> + unsigned int len)
> +{
> + unsigned long flags;
> + struct meson_irtx *ir = rc->priv;
> +
> + if (!meson_irtx_check_buf(ir, buf, len))
> + return -EINVAL;
> +
> + spin_lock_irqsave(&ir->lock, flags);
> + ir->buf = kmalloc_array(len, sizeof(u32), GFP_KERNEL);
Please don't call kmalloc() while holding a spinlock, the kmalloc() could
take some time.
> + if (!ir->buf)
> + return -ENOMEM;
> +
> + ir->buf_len = len;
> + ir->buf_head = 0;
> + meson_irtx_fill_buf(ir, buf);
Please lock the spinlock after populating the buffer, and only then assign
the ir->buf/buf_len/buf_head. It's the assignement to ir->buf/ir->buf_head
etc that we are trying to protect.
> + spin_unlock_irqrestore(&ir->lock, flags);
> +
> + reinit_completion(&ir->completion);
> + dev_dbg(ir->dev, "tx started, buffer length = %u\n", ir->buf_len);
> +
> + spin_lock_irqsave(&ir->lock, flags);
You might be able to do that here so you avoid the spin_lock/spin_unlock
above.
> + meson_irtx_send_buffer(ir);
> + spin_unlock_irqrestore(&ir->lock, flags);
> +
> + wait_for_completion_interruptible(&ir->completion);
> + dev_dbg(ir->dev, "tx completed\n");
> +
> + spin_lock_irqsave(&ir->lock, flags);
> + kfree(ir->buf);
> + ir->buf = NULL;
> + ir->buf_len = 0;
> + spin_unlock_irqrestore(&ir->lock, flags);
> +
> + return len;
> +}
> +
> +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;
> + }
> +
> + if (of_property_read_u32(dev->of_node, "max-fifo-level",
> + &ir->max_fifo_level))
> + ir->max_fifo_level = MIRTX_DEFAULT_MAX_FIFO_LEVEL;
> + else if (ir->max_fifo_level > IRB_FIFO_LEN)
> + ir->max_fifo_level = MIRTX_DEFAULT_MAX_FIFO_LEVEL;
> + dev_dbg(dev, "max FIFO level set to %u\n", ir->max_fifo_level);
> +
> + 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 <[email protected]>");
> +MODULE_LICENSE("GPL");
> --
> 2.21.0
Hi Viktor,
On Mon, Jul 12, 2021 at 10:17 PM Viktor Prutyanov
<[email protected]> wrote:
[...]
> + max-fifo-level:
> + maxItems: 1
> + description:
> + Maximum IR TX FIFO fill level
From Documentation/devicetree/bindings/writing-bindings.rst:
"DO use a vendor prefix on device specific property names. Consider if
properties could be common among devices of the same class. Check
other existing bindings for similar devices."
I am not sure if there's a "common" fifo size property for IR
transmitters though.
Also in general I think it's good to write the schema for properties
in a way so the binding validation can detect issues.
For "common" properties (like clocks, interrupts, etc.) this is
inherited by default
However, for custom properties this needs to be defined manually.
For this property I would add:
$ref: /schemas/types.yaml#/definitions/uint32
(I think this can replace maxItems)
And I would define the allowed value, from what I have seen in the
vendor driver (which I am not sure about though!) that would be:
const: 1024
Best regards,
Martin