Re: [PATCH V2 4/4] irq: imx: irqsteer: add multi output interrupts support

[Lucas Stach <l.stach@pengutronix.de>]

Am Mittwoch, den 30.01.2019, 13:06 +0000 schrieb Aisheng Dong:
> One irqsteer channel can support up to 8 output interrupts.
> 
> > Cc: Marc Zyngier <marc.zyngier@arm.com>
> > Cc: Lucas Stach <l.stach@pengutronix.de>
> > Cc: Shawn Guo <shawnguo@kernel.org>
> > Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
> ---
> ChangeLog:
> v1->v2:
>  * calculate irq_count by fsl,num-irqs instead of parsing interrupts
>    property from devicetree to match the input interrupts and outputs
>  * improve output interrupt handler by searching only two registers
>    withint the same group
> ---
>  drivers/irqchip/irq-imx-irqsteer.c | 76 +++++++++++++++++++++++++++++---------
>  1 file changed, 59 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/irqchip/irq-imx-irqsteer.c b/drivers/irqchip/irq-imx-irqsteer.c
> index 67ed862..cc40039 100644
> --- a/drivers/irqchip/irq-imx-irqsteer.c
> +++ b/drivers/irqchip/irq-imx-irqsteer.c
> @@ -10,6 +10,7 @@
>  #include <linux/irqchip/chained_irq.h>
>  #include <linux/irqdomain.h>
>  #include <linux/kernel.h>
> +#include <linux/of_irq.h>
>  #include <linux/of_platform.h>
>  #include <linux/spinlock.h>
>  
> @@ -21,10 +22,13 @@
> >  #define CHAN_MINTDIS(t)		(CTRL_STRIDE_OFF(t, 3) + 0x4)
> >  #define CHAN_MASTRSTAT(t)	(CTRL_STRIDE_OFF(t, 3) + 0x8)
>  
> > +#define CHAN_MAX_OUTPUT_INT	0x8
> +
>  struct irqsteer_data {
> > >  	void __iomem		*regs;
> > >  	struct clk		*ipg_clk;
> > > -	int			irq;
> > > +	int			irq[CHAN_MAX_OUTPUT_INT];
> > > +	int			irq_count;
> > >  	raw_spinlock_t		lock;
> > >  	int			reg_num;
> > >  	int			channel;
> @@ -87,26 +91,45 @@ static const struct irq_domain_ops imx_irqsteer_domain_ops = {
> > >  	.xlate		= irq_domain_xlate_onecell,
>  };
>  
> +static int imx_irqsteer_get_hwirq_base(struct irqsteer_data *data, u32 irq)
> +{
> > +	int i;
> +
> > +	for (i = 0; i < data->irq_count; i++) {
> > +		if (data->irq[i] == irq)
> +			break;

return i * 64; here...
> +	}
> +
> +	return i * 64;

... and -EINVAL or something here, so we don't return a out of bounds
hwirq base if the loop ever doesn't match something?
 
> +}
> +
>  static void imx_irqsteer_irq_handler(struct irq_desc *desc)
>  {
> >  	struct irqsteer_data *data = irq_desc_get_handler_data(desc);
> > +	int hwirq;
> >  	int i;
>  
> >  	chained_irq_enter(irq_desc_get_chip(desc), desc);
>  
> > -	for (i = 0; i < data->reg_num * 32; i += 32) {
> > -		int idx = imx_irqsteer_get_reg_index(data, i);
> > +	hwirq = imx_irqsteer_get_hwirq_base(data, irq_desc_get_irq(desc));
> +
> > +	for (i = 0; i < 2; i++) {
> > +		int idx = imx_irqsteer_get_reg_index(data, hwirq);
> >  		unsigned long irqmap;
> >  		int pos, virq;
>  
> > +		if (hwirq >= data->reg_num * 32)
> > +			break;
> +
> >  		irqmap = readl_relaxed(data->regs +
> >  				       CHANSTATUS(idx, data->reg_num));
>  
> >  		for_each_set_bit(pos, &irqmap, 32) {
> > -			virq = irq_find_mapping(data->domain, pos + i);
> +			virq = irq_find_mapping(data->domain, pos + hwirq);

The irq index calculation need to be "pos + i * 32 + hwirq", otherwise
this will map to the wrong virqs for the second register in each group.

>  			if (virq)
> >  				generic_handle_irq(virq);
> >  		}
> +		hwirq += 32;

Could be folded into the loop head.

>  	}
>  
> >  	chained_irq_exit(irq_desc_get_chip(desc), desc);
> @@ -117,7 +140,8 @@ static int imx_irqsteer_probe(struct platform_device *pdev)
> >  	struct device_node *np = pdev->dev.of_node;
> >  	struct irqsteer_data *data;
> >  	struct resource *res;
> > -	int ret;
> > +	u32 irqs_num;
> > +	int i, ret;
>  
> >  	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> >  	if (!data)
> @@ -130,12 +154,6 @@ static int imx_irqsteer_probe(struct platform_device *pdev)
> >  		return PTR_ERR(data->regs);
> >  	}
>  
> > -	data->irq = platform_get_irq(pdev, 0);
> > -	if (data->irq <= 0) {
> > -		dev_err(&pdev->dev, "failed to get irq\n");
> > -		return -ENODEV;
> > -	}
> -
> >  	data->ipg_clk = devm_clk_get(&pdev->dev, "ipg");
> >  	if (IS_ERR(data->ipg_clk)) {
> >  		ret = PTR_ERR(data->ipg_clk);
> @@ -146,11 +164,17 @@ static int imx_irqsteer_probe(struct platform_device *pdev)
>  
> >  	raw_spin_lock_init(&data->lock);
>  
> > -	of_property_read_u32(np, "fsl,num-irqs", &data->reg_num);
> > +	of_property_read_u32(np, "fsl,num-irqs", &irqs_num);
> >  	of_property_read_u32(np, "fsl,channel", &data->channel);
>  
> > -	/* one register bit map represents 32 input interrupts */
> > -	data->reg_num /= 32;
> > +	/*
> +	 * There is one output irqs for each group of 64 inputs.

"irq", singular.

> +	 * One register bit map can represent 32 input interrupts.
> > +	 */
> > +	data->irq_count = irqs_num / 64;
> > +	if (irqs_num % 64)
> +		data->irq_count += 1;

This is a weird way of writing DIV_ROUND_UP.

> +	data->reg_num = irqs_num / 32;
>  
> >  	if (IS_ENABLED(CONFIG_PM_SLEEP)) {
> >  		data->saved_reg = devm_kzalloc(&pdev->dev,
> @@ -177,8 +201,22 @@ static int imx_irqsteer_probe(struct platform_device *pdev)
> >  		return -ENOMEM;
> >  	}
>  
> > -	irq_set_chained_handler_and_data(data->irq, imx_irqsteer_irq_handler,
> > -					 data);
> > +	if (!data->irq_count || data->irq_count > CHAN_MAX_OUTPUT_INT) {
> > +		clk_disable_unprepare(data->ipg_clk);
> > +		return -EINVAL;
> > +	}
> +
> > +	for (i = 0; i < data->irq_count; i++) {
> > +		data->irq[i] = irq_of_parse_and_map(np, i);
> > +		if (!data->irq[i]) {
> > +			clk_disable_unprepare(data->ipg_clk);
> +			return -EINVAL;

With a lot of failure paths now replicating the clk_disable_unprepare,
return error, I think this warrants a common cleanup path that all
those paths could reach via simple goto.

> +		}
> +
> > +		irq_set_chained_handler_and_data(data->irq[i],
> > +						 imx_irqsteer_irq_handler,
> > +						 data);
> > +	}
>  
> >  	platform_set_drvdata(pdev, data);
>  
> @@ -188,8 +226,12 @@ static int imx_irqsteer_probe(struct platform_device *pdev)
>  static int imx_irqsteer_remove(struct platform_device *pdev)
>  {
> >  	struct irqsteer_data *irqsteer_data = platform_get_drvdata(pdev);
> > +	int i;
> +
> > +	for (i = 0; i < irqsteer_data->irq_count; i++)
> > +		irq_set_chained_handler_and_data(irqsteer_data->irq[i],
> > +						 NULL, NULL);
>  
> > -	irq_set_chained_handler_and_data(irqsteer_data->irq, NULL, NULL);
> >  	irq_domain_remove(irqsteer_data->domain);
>  
> >  	clk_disable_unprepare(irqsteer_data->ipg_clk);