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[23.128.96.18]) by mx.google.com with ESMTP id u12si8278991ilm.99.2021.07.09.15.12.22; Fri, 09 Jul 2021 15:12:34 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=fail header.i=@mess.org header.s=2020 header.b=Lat8P29I; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231216AbhGIWOM (ORCPT + 99 others); Fri, 9 Jul 2021 18:14:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51736 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229552AbhGIWOM (ORCPT ); Fri, 9 Jul 2021 18:14:12 -0400 Received: from gofer.mess.org (gofer.mess.org [IPv6:2a02:8011:d000:212::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 34938C0613DD; Fri, 9 Jul 2021 15:11:28 -0700 (PDT) Received: by gofer.mess.org (Postfix, from userid 1000) id 083A6C6349; Fri, 9 Jul 2021 23:11:25 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=mess.org; s=2020; t=1625868685; bh=VzoMJLTBOWaLkJ4ticoaaU1Qg0X6A0sEdFxheLOHvqI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Lat8P29IDFv2N3lbrv7Fbl3X3DvEWR25VKU8qFpRKAA0DsGgepO+9k7shv4Hil1wh cyXcS25qlE0HzmFbDeCdyHexIFlMQEDAjlwVB9AKK8ONQVdX0WnfH9vsCwMuMOSQW9 OAeOrkhoku+nH0AVP7MEMWgubAHGUOcdInw8bZiwgHbJPmFTkn1r8DLmJeeq1uVE7r Da2Kdt2f9cQ48LVBHrAjnh3idFOJxX4LCjXSnCZzdwpypUEJyjXI94kbvPDlKG3PoN wxvfX4B/CDyetU+7PaKXltEugHmDT/NiEoVJYwJKC0vdl23nHaJ1jAHidI9qLcCgJF 7awov5yc1TPBw== Date: Fri, 9 Jul 2021 23:11:24 +0100 From: Sean Young To: Viktor Prutyanov Cc: mchehab@kernel.org, robh+dt@kernel.org, khilman@baylibre.com, narmstrong@baylibre.com, jbrunet@baylibre.com, martin.blumenstingl@googlemail.com, linux-media@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org, rockosov@gmail.com Subject: Re: [PATCH v3 2/2] media: rc: introduce Meson IR blaster driver Message-ID: <20210709221124.GA22240@gofer.mess.org> References: <20210709165753.29353-1-viktor.prutyanov@phystech.edu> <20210709165753.29353-3-viktor.prutyanov@phystech.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210709165753.29353-3-viktor.prutyanov@phystech.edu> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Viktor, The driver look great! Thanks for making those changes. Just two minor comments. On Fri, Jul 09, 2021 at 07:57:53PM +0300, Viktor Prutyanov wrote: > This patch adds the driver for Amlogic Meson IR blaster. > > Some Amlogic SoCs such as A311D and T950D4 have IR transmitter > (blaster) controller onboard. It is capable of sending IR > signals with arbitrary carrier frequency and duty cycle. > > The driver supports 3 modulation clock sources: > - sysclk > - xtal3 clock (xtal divided by 3) > - 1us clock > > Signed-off-by: Viktor Prutyanov > --- > 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 > > drivers/media/rc/Kconfig | 10 + > drivers/media/rc/Makefile | 1 + > drivers/media/rc/meson-irblaster.c | 400 +++++++++++++++++++++++++++++ > 3 files changed, 411 insertions(+) > create mode 100644 drivers/media/rc/meson-irblaster.c > > diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig > index d0a8326b75c2..6e60348e1bcf 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_IRBLASTER > + tristate "Amlogic Meson IR blaster" > + depends on ARCH_MESON || COMPILE_TEST > + help > + Say Y if you want to use the IR blaster available on > + Amlogic Meson SoCs. > + > + To compile this driver as a module, choose M here: the > + module will be called meson-irblaster. > + > 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..b108f2b0420c 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-$(CONFIG_IR_MESON_IRBLASTER) += meson-irblaster.o > obj-$(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-irblaster.c b/drivers/media/rc/meson-irblaster.c > new file mode 100644 > index 000000000000..758d9abf252e > --- /dev/null > +++ b/drivers/media/rc/meson-irblaster.c > @@ -0,0 +1,400 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/** > + * meson-irblaster.c - Amlogic Meson IR blaster driver > + * > + * Copyright (c) 2021, SberDevices. All Rights Reserved. > + * > + * Author: Viktor Prutyanov > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define DEVICE_NAME "Meson IR blaster" > +#define DRIVER_NAME "meson-irblaster" This driver uses the term "blaster" rather "transmitter" or "tx". Is there a good reason for this? None of the other IR transmitters use the term blaster; the rc core kapi also only talks about tx. "IR Blaster" seems like a marketing term for what is essentially a led switching on and off. > + > +#define IRB_MOD_1US_CLK_RATE 1000000 > + > +#define IRB_DEFAULT_CARRIER 38000 > +#define IRB_DEFAULT_DUTY_CYCLE 50 > + > +#define IRB_FIFO_LEN 128 > +#define IRB_DEFAULT_MAX_FIFO_LEVEL 96 > + > +#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 irblaster_dev { > + 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 irb_set_mod(struct irblaster_dev *irb) > +{ > + unsigned int cnt = DIV_ROUND_CLOSEST(irb->clk_rate, irb->carrier); > + unsigned int pulse_cnt = DIV_ROUND_CLOSEST(cnt * irb->duty_cycle, 100); > + unsigned int space_cnt = cnt - pulse_cnt; > + > + dev_dbg(irb->dev, "F_mod = %uHz, T_mod = %luns, duty_cycle = %u%%\n", > + irb->carrier, NSEC_PER_SEC / irb->clk_rate * cnt, > + 100 * pulse_cnt / cnt); > + > + writel(IRB_MOD_COUNT(pulse_cnt, space_cnt), > + irb->reg_base + IRB_ADDR1); > +} > + > +static void irb_setup(struct irblaster_dev *irb, unsigned int clk_nr) > +{ > + unsigned int fifo_irq_threshold = IRB_FIFO_LEN - irb->max_fifo_level; > + > + /* > + * Disable the blaster, 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 blaster back. > + */ > + writel(~IRB_ENABLE & (IRB_MOD_CLK(clk_nr) | IRB_INIT_HIGH), > + irb->reg_base + IRB_ADDR0); > + irb_set_mod(irb); > + writel(readl(irb->reg_base + IRB_ADDR0) & ~IRB_INIT_HIGH, > + irb->reg_base + IRB_ADDR0); > + writel(IRB_FIFO_IRQ_ENABLE | fifo_irq_threshold, > + irb->reg_base + IRB_ADDR3); > + writel(readl(irb->reg_base + IRB_ADDR0) | IRB_ENABLE, > + irb->reg_base + IRB_ADDR0); > +} > + > +static u32 irb_prepare_pulse(struct irblaster_dev *irb, unsigned int time) > +{ > + unsigned int delay; > + unsigned int tb = IRB_TB_MOD_CLK; > + unsigned int tb_us = DIV_ROUND_CLOSEST(USEC_PER_SEC, irb->carrier); > + > + delay = (DIV_ROUND_CLOSEST(time, tb_us) - 1) & IRB_DELAY_MASK; > + > + return ((IRB_WRITE_FIFO | IRB_MOD_ENABLE) | tb | delay); > +} > + > +static u32 irb_prepare_space(struct irblaster_dev *irb, 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 irb_send_buffer(struct irblaster_dev *irb) > +{ > + unsigned int nr = 0; > + > + while (irb->buf_head < irb->buf_len && nr < irb->max_fifo_level) { > + writel(irb->buf[irb->buf_head], irb->reg_base + IRB_ADDR2); > + > + irb->buf_head++; > + nr++; > + } > +} > + > +static bool irb_check_buf(struct irblaster_dev *irb, > + 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 / irb->carrier; > + else > + max_tb_us = 100; > + > + if (buf[i] >= max_tb_us * IRB_MAX_DELAY) > + return false; > + } > + > + return true; > +} > + > +static void irb_fill_buf(struct irblaster_dev *irb, unsigned int *buf) > +{ > + unsigned int i; > + > + for (i = 0; i < irb->buf_len; i++) { > + if (i % 2 == 0) > + irb->buf[i] = irb_prepare_pulse(irb, buf[i]); > + else > + irb->buf[i] = irb_prepare_space(irb, buf[i]); > + } > +} > + > +static irqreturn_t irb_irqhandler(int irq, void *data) > +{ > + unsigned long flags; > + struct irblaster_dev *irb = data; > + > + writel(readl(irb->reg_base + IRB_ADDR3) & ~IRB_FIFO_THD_PENDING, > + irb->reg_base + IRB_ADDR3); > + > + spin_lock_irqsave(&irb->lock, flags); > + if (irb->buf_head < irb->buf_len) > + irb_send_buffer(irb); > + else > + complete(&irb->completion); > + spin_unlock_irqrestore(&irb->lock, flags); > + > + return IRQ_HANDLED; > +} > + > +static int irb_set_tx_carrier(struct rc_dev *rc, u32 carrier) > +{ > + struct irblaster_dev *irb = rc->priv; > + > + if (carrier == 0) > + return -EINVAL; > + > + irb->carrier = carrier; > + irb_set_mod(irb); > + > + return 0; > +} > + > +static int irb_set_tx_duty_cycle(struct rc_dev *rc, u32 duty_cycle) > +{ > + struct irblaster_dev *irb = rc->priv; > + > + irb->duty_cycle = duty_cycle; > + irb_set_mod(irb); > + > + return 0; > +} > + > +static int irb_tx_ir(struct rc_dev *rc, unsigned int *buf, unsigned int len) > +{ > + unsigned long flags; > + struct irblaster_dev *irb = rc->priv; > + > + if (!irb_check_buf(irb, buf, len)) > + return -EINVAL; > + > + irb->buf = kmalloc_array(len, sizeof(u32), GFP_KERNEL); Right now the interrupt handler could still called, if the previous tx was interrupted early with a signal. This should also be in spinlock so we make sure we are not sending garbage. > + if (!irb->buf) > + return -ENOMEM; > + > + irb->buf_len = len; > + irb->buf_head = 0; > + irb_fill_buf(irb, buf); > + > + reinit_completion(&irb->completion); > + > + dev_dbg(irb->dev, "tx started, buffer length = %u\n", irb->buf_len); > + spin_lock_irqsave(&irb->lock, flags); > + irb_send_buffer(irb); > + spin_unlock_irqrestore(&irb->lock, flags); > + wait_for_completion_interruptible(&irb->completion); > + dev_dbg(irb->dev, "tx completed\n"); Here the debug talks about tx, not blasting. > + > + spin_lock_irqsave(&irb->lock, flags); > + kfree(irb->buf); > + irb->buf = NULL; > + irb->buf_len = 0; > + spin_unlock_irqrestore(&irb->lock, flags); > + > + return len; > +} > + > +static int irb_mod_clock_probe(struct irblaster_dev *irb, unsigned int *clk_nr) > +{ > + struct device_node *np = irb->dev->of_node; > + struct clk *clock; > + > + if (!np) > + return -ENODEV; > + > + clock = devm_clk_get(irb->dev, "xtal"); > + if (IS_ERR(clock) || clk_prepare_enable(clock)) > + return -ENODEV; > + > + *clk_nr = IRB_MOD_XTAL3_CLK; > + irb->clk_rate = clk_get_rate(clock) / 3; > + > + if (irb->clk_rate < IRB_MOD_1US_CLK_RATE) { > + *clk_nr = IRB_MOD_1US_CLK; > + irb->clk_rate = IRB_MOD_1US_CLK_RATE; > + } > + > + dev_info(irb->dev, "F_clk = %luHz\n", irb->clk_rate); > + > + return 0; > +} > + > +static int __init irblaster_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct irblaster_dev *irb; > + struct rc_dev *rc; > + int irq; > + unsigned int clk_nr; > + int ret; > + > + irb = devm_kzalloc(dev, sizeof(*irb), GFP_KERNEL); > + if (!irb) > + return -ENOMEM; > + > + irb->reg_base = devm_platform_ioremap_resource(pdev, 0); > + if (IS_ERR(irb->reg_base)) > + return PTR_ERR(irb->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", > + &irb->max_fifo_level)) > + irb->max_fifo_level = IRB_DEFAULT_MAX_FIFO_LEVEL; > + else if (irb->max_fifo_level > IRB_FIFO_LEN) > + irb->max_fifo_level = IRB_DEFAULT_MAX_FIFO_LEVEL; > + dev_dbg(dev, "max FIFO level set to %u\n", irb->max_fifo_level); > + > + irb->dev = dev; > + irb->carrier = IRB_DEFAULT_CARRIER; > + irb->duty_cycle = IRB_DEFAULT_DUTY_CYCLE; > + init_completion(&irb->completion); > + spin_lock_init(&irb->lock); > + > + ret = irb_mod_clock_probe(irb, &clk_nr); > + if (ret) { > + dev_err(dev, "modulator clock setup failed\n"); > + return ret; > + } > + irb_setup(irb, clk_nr); > + > + ret = devm_request_irq(dev, irq, > + irb_irqhandler, > + IRQF_TRIGGER_RISING, > + DRIVER_NAME, irb); > + 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 = irb; > + > + rc->tx_ir = irb_tx_ir; > + rc->s_tx_carrier = irb_set_tx_carrier; > + rc->s_tx_duty_cycle = irb_set_tx_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 irblaster_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 irblaster_dt_match[] = { > + { > + .compatible = "amlogic,meson-g12a-irblaster", > + }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, irblaster_dt_match); > + > +static struct platform_driver irblaster_pd = { > + .remove = irblaster_remove, > + .driver = { > + .name = DRIVER_NAME, > + .owner = THIS_MODULE, > + .of_match_table = irblaster_dt_match, > + }, > +}; > + > +module_platform_driver_probe(irblaster_pd, irblaster_probe); > + > +MODULE_DESCRIPTION("Meson IR blaster driver"); > +MODULE_AUTHOR("Viktor Prutyanov "); > +MODULE_LICENSE("GPL"); > -- > 2.21.0