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Date: Wed, 13 Jan 2021 09:00:20 -0600
From: Samuel Holland <samuel@...lland.org>
To: Sean Young <sean@...s.org>
Cc: Mauro Carvalho Chehab <mchehab@...nel.org>,
Maxime Ripard <mripard@...nel.org>,
Chen-Yu Tsai <wens@...e.org>,
Jernej Skrabec <jernej.skrabec@...l.net>,
linux-media@...r.kernel.org, linux-kernel@...r.kernel.org,
linux-sunxi@...glegroups.com
Subject: Re: [PATCH 3/4] media: sunxi-cir: Factor out hardware initialization
On 1/13/21 8:36 AM, Sean Young wrote:
> On Tue, Jan 12, 2021 at 10:51:31PM -0600, Samuel Holland wrote:
>> In preparation for adding suspend/resume hooks, factor out the hardware
>> initialization from the driver probe/remove functions.
>>
>> The timeout programmed during init is taken from the `struct rc_dev` so
>> it is maintained across an exit/init cycle.
>>
>> This resolves some trivial issues with the probe function: throwing away
>> the error from clk_prepare_enable and using the wrong type for the
>> temporary register value.
>>
>> Signed-off-by: Samuel Holland <samuel@...lland.org>
>> ---
>> drivers/media/rc/sunxi-cir.c | 128 ++++++++++++++++++++---------------
>> 1 file changed, 74 insertions(+), 54 deletions(-)
>>
>> diff --git a/drivers/media/rc/sunxi-cir.c b/drivers/media/rc/sunxi-cir.c
>> index 48be400421cd..ccb9d6b4225d 100644
>> --- a/drivers/media/rc/sunxi-cir.c
>> +++ b/drivers/media/rc/sunxi-cir.c
>> @@ -169,10 +169,74 @@ static int sunxi_ir_set_timeout(struct rc_dev *rc_dev, unsigned int timeout)
>> return 0;
>> }
>>
>> +static int sunxi_ir_hw_init(struct device *dev)
>> +{
>> + struct sunxi_ir *ir = dev_get_drvdata(dev);
>> + u32 tmp;
>> + int ret;
>> +
>> + ret = reset_control_deassert(ir->rst);
>> + if (ret)
>> + return ret;
>> +
>> + ret = clk_prepare_enable(ir->apb_clk);
>> + if (ret) {
>> + dev_err(dev, "failed to enable apb clk\n");
>> + goto exit_assert_reset;
>> + }
>> +
>> + ret = clk_prepare_enable(ir->clk);
>> + if (ret) {
>> + dev_err(dev, "failed to enable ir clk\n");
>> + goto exit_disable_apb_clk;
>> + }
>> +
>> + /* Enable CIR Mode */
>> + writel(REG_CTL_MD, ir->base + SUNXI_IR_CTL_REG);
>> +
>> + /* Set noise threshold and idle threshold */
>> + sunxi_ir_set_timeout(ir->rc, ir->rc->timeout);
Initializing ir->rc->timeout in .probe is needed because of this line.
As the changelog mentions, this reprograms the user-configured timeout
after an exit/init (suspend/resume) cycle. It needs some default value
the first time, when called from .probe.
>> +
>> + /* Invert Input Signal */
>> + writel(REG_RXCTL_RPPI, ir->base + SUNXI_IR_RXCTL_REG);
>> +
>> + /* Clear All Rx Interrupt Status */
>> + writel(REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
>> +
>> + /*
>> + * Enable IRQ on overflow, packet end, FIFO available with trigger
>> + * level
>> + */
>> + writel(REG_RXINT_ROI_EN | REG_RXINT_RPEI_EN |
>> + REG_RXINT_RAI_EN | REG_RXINT_RAL(ir->fifo_size / 2 - 1),
>> + ir->base + SUNXI_IR_RXINT_REG);
>> +
>> + /* Enable IR Module */
>> + tmp = readl(ir->base + SUNXI_IR_CTL_REG);
>> + writel(tmp | REG_CTL_GEN | REG_CTL_RXEN, ir->base + SUNXI_IR_CTL_REG);
>> +
>> + return 0;
>> +
>> +exit_disable_apb_clk:
>> + clk_disable_unprepare(ir->apb_clk);
>> +exit_assert_reset:
>> + reset_control_assert(ir->rst);
>> +
>> + return ret;
>> +}
>> +
>> +static void sunxi_ir_hw_exit(struct device *dev)
>> +{
>> + struct sunxi_ir *ir = dev_get_drvdata(dev);
>> +
>> + clk_disable_unprepare(ir->clk);
>> + clk_disable_unprepare(ir->apb_clk);
>> + reset_control_assert(ir->rst);
>> +}
>> +
>> static int sunxi_ir_probe(struct platform_device *pdev)
>> {
>> int ret = 0;
>> - unsigned long tmp = 0;
>>
>> struct device *dev = &pdev->dev;
>> struct device_node *dn = dev->of_node;
>> @@ -213,43 +277,26 @@ static int sunxi_ir_probe(struct platform_device *pdev)
>> ir->rst = devm_reset_control_get_exclusive(dev, NULL);
>> if (IS_ERR(ir->rst))
>> return PTR_ERR(ir->rst);
>> - ret = reset_control_deassert(ir->rst);
>> - if (ret)
>> - return ret;
>> }
>>
>> ret = clk_set_rate(ir->clk, b_clk_freq);
>> if (ret) {
>> dev_err(dev, "set ir base clock failed!\n");
>> - goto exit_reset_assert;
>> + return ret;
>> }
>> dev_dbg(dev, "set base clock frequency to %d Hz.\n", b_clk_freq);
>>
>> - if (clk_prepare_enable(ir->apb_clk)) {
>> - dev_err(dev, "try to enable apb_ir_clk failed\n");
>> - ret = -EINVAL;
>> - goto exit_reset_assert;
>> - }
>> -
>> - if (clk_prepare_enable(ir->clk)) {
>> - dev_err(dev, "try to enable ir_clk failed\n");
>> - ret = -EINVAL;
>> - goto exit_clkdisable_apb_clk;
>> - }
>> -
>> /* IO */
>> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> ir->base = devm_ioremap_resource(dev, res);
>> if (IS_ERR(ir->base)) {
>> - ret = PTR_ERR(ir->base);
>> - goto exit_clkdisable_clk;
>> + return PTR_ERR(ir->base);
>> }
>>
>> ir->rc = rc_allocate_device(RC_DRIVER_IR_RAW);
>> if (!ir->rc) {
>> dev_err(dev, "failed to allocate device\n");
>> - ret = -ENOMEM;
>> - goto exit_clkdisable_clk;
>> + return -ENOMEM;
>> }
>>
>> ir->rc->priv = ir;
>> @@ -265,6 +312,7 @@ static int sunxi_ir_probe(struct platform_device *pdev)
>> ir->rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
>> /* Frequency after IR internal divider with sample period in us */
>> ir->rc->rx_resolution = (USEC_PER_SEC / (b_clk_freq / 64));
>> + ir->rc->timeout = IR_DEFAULT_TIMEOUT;
>
> Why? This is set from sunxi_ir_set_timeout().
Because it is also sent as an argument to sunxi_ir_set_timeout().
>> ir->rc->min_timeout = sunxi_ithr_to_usec(b_clk_freq, 0);
>> ir->rc->max_timeout = sunxi_ithr_to_usec(b_clk_freq, 255);
>> ir->rc->s_timeout = sunxi_ir_set_timeout;
>> @@ -291,41 +339,15 @@ static int sunxi_ir_probe(struct platform_device *pdev)
>> goto exit_free_dev;
>> }
>>
>> - /* Enable CIR Mode */
>> - writel(REG_CTL_MD, ir->base+SUNXI_IR_CTL_REG);
>> -
>> - /* Set noise threshold and idle threshold */
>> - sunxi_ir_set_timeout(ir->rc, IR_DEFAULT_TIMEOUT);
This is where the default timeout was originally programmed.
>> -
>> - /* Invert Input Signal */
>> - writel(REG_RXCTL_RPPI, ir->base + SUNXI_IR_RXCTL_REG);
>> -
>> - /* Clear All Rx Interrupt Status */
>> - writel(REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
>> -
>> - /*
>> - * Enable IRQ on overflow, packet end, FIFO available with trigger
>> - * level
>> - */
>> - writel(REG_RXINT_ROI_EN | REG_RXINT_RPEI_EN |
>> - REG_RXINT_RAI_EN | REG_RXINT_RAL(ir->fifo_size / 2 - 1),
>> - ir->base + SUNXI_IR_RXINT_REG);
>> -
>> - /* Enable IR Module */
>> - tmp = readl(ir->base + SUNXI_IR_CTL_REG);
>> - writel(tmp | REG_CTL_GEN | REG_CTL_RXEN, ir->base + SUNXI_IR_CTL_REG);
>> + ret = sunxi_ir_hw_init(dev);
>> + if (ret)
>> + goto exit_free_dev;
>>
>> dev_info(dev, "initialized sunXi IR driver\n");
>> return 0;
>>
>> exit_free_dev:
>> rc_free_device(ir->rc);
>> -exit_clkdisable_clk:
>> - clk_disable_unprepare(ir->clk);
>> -exit_clkdisable_apb_clk:
>> - clk_disable_unprepare(ir->apb_clk);
>> -exit_reset_assert:
>> - reset_control_assert(ir->rst);
>>
>> return ret;
>> }
>> @@ -334,11 +356,9 @@ static int sunxi_ir_remove(struct platform_device *pdev)
>> {
>> struct sunxi_ir *ir = platform_get_drvdata(pdev);
>>
>> - clk_disable_unprepare(ir->clk);
>> - clk_disable_unprepare(ir->apb_clk);
>> - reset_control_assert(ir->rst);
>> -
>> + sunxi_ir_hw_exit(&pdev->dev);
>> rc_unregister_device(ir->rc);
I can swap these lines to fix your comment on patch 1.
>> +
>> return 0;
>> }
>>
>> --
>> 2.26.2
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