Re: [PATCH] irqchip: renesas-intc-irqpin: r8a7779 IRLM setup support

[Jason Cooper <jason@lakedaemon.net>]

On Mon, Dec 15, 2014 at 02:09:20PM +0900, Magnus Damm wrote:
> From: Magnus Damm <damm+renesas@opensource.se>
> 
> Add r8a7779 specific support for IRLM bit configuration
> in the INTC-IRQPIN driver. Without this code we need
> special workaround code in arch/arm/mach-shmobile.
> 
> The IRLM bit for the INTC hardware exists on various
> older SH-based SoCs and is used to select between two
> modes for the external interrupt pins IRQ0 to IRQ3:
> 
> IRLM = 0: (default from reset on r8a7779)
> In this mode the pins IRQ0 to IRQ3 are used together
> to give a value between 0 and 15 to the SoC. External
> logic is required for masking. This mode is not
> supported by the INTC-IRQPIN driver.
> 
> IRLM = 1: (needs this patch or configuration elsewhere)
> In this mode IRQ0 to IRQ3 operate as 4 individual
> external interrupt pins. In this mode the SMSC ethernet
> chip can be used via IRQ1 on r8a7779 Marzen. This mode
> is the only supported mode by the INTC-IRQPIN driver.
> 
> For this patch to work the r8a7779 DTS needs to pass
> the ICR0 register as the last register bank.
> 
> Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
> ---
> 
>  Same version as sent on December 3rd.
> 
>  Written against renesas-devel-20141202-v3.18-rc7 which is
>  basically v3.18-rc7 plus latest arch/arm/mach-shmobile code.
>  
>  Documentation/devicetree/bindings/interrupt-controller/renesas,intc-irqpin.txt |    5 +
>  drivers/irqchip/irq-renesas-intc-irqpin.c                                      |   50 ++++++++--
>  2 files changed, 46 insertions(+), 9 deletions(-)
> 
> --- 0001/Documentation/devicetree/bindings/interrupt-controller/renesas,intc-irqpin.txt
> +++ work/Documentation/devicetree/bindings/interrupt-controller/renesas,intc-irqpin.txt	2014-12-03 20:25:13.000000000 +0900
> @@ -9,6 +9,11 @@ Required properties:
>      - "renesas,intc-irqpin-r8a7778" (R-Car M1A)
>      - "renesas,intc-irqpin-r8a7779" (R-Car H1)
>      - "renesas,intc-irqpin-sh73a0" (SH-Mobile AG5)
> +
> +- reg: Base address and length of each register bank used by the external
> +  IRQ pins driven by the interrupt controller hardware module. The base
> +  addresses, length and number of required register banks varies with soctype.
> +
>  - #interrupt-cells: has to be <2>: an interrupt index and flags, as defined in
>    interrupts.txt in this directory
>  
> --- 0001/drivers/irqchip/irq-renesas-intc-irqpin.c
> +++ work/drivers/irqchip/irq-renesas-intc-irqpin.c	2014-12-03 20:32:59.000000000 +0900
> @@ -30,6 +30,7 @@
>  #include <linux/err.h>
>  #include <linux/slab.h>
>  #include <linux/module.h>
> +#include <linux/of_device.h>
>  #include <linux/platform_data/irq-renesas-intc-irqpin.h>
>  #include <linux/pm_runtime.h>
>  
> @@ -40,7 +41,9 @@
>  #define INTC_IRQPIN_REG_SOURCE 2 /* INTREQnn */
>  #define INTC_IRQPIN_REG_MASK 3 /* INTMSKnn */
>  #define INTC_IRQPIN_REG_CLEAR 4 /* INTMSKCLRnn */
> -#define INTC_IRQPIN_REG_NR 5
> +#define INTC_IRQPIN_REG_NR_MANDATORY 5
> +#define INTC_IRQPIN_REG_IRLM 5 /* ICR0 with IRLM bit (optional) */
> +#define INTC_IRQPIN_REG_NR 6
>  
>  /* INTC external IRQ PIN hardware register access:
>   *
> @@ -82,6 +85,10 @@ struct intc_irqpin_priv {
>  	u8 shared_irq_mask;
>  };
>  
> +struct intc_irqpin_irlm_config {
> +	unsigned int irlm_bit;
> +};
> +
>  static unsigned long intc_irqpin_read32(void __iomem *iomem)
>  {
>  	return ioread32(iomem);
> @@ -345,10 +352,23 @@ static struct irq_domain_ops intc_irqpin
>  	.xlate  = irq_domain_xlate_twocell,
>  };
>  
> +static const struct intc_irqpin_irlm_config intc_irqpin_irlm_r8a7779 = {
> +	.irlm_bit = 23, /* ICR0.IRLM0 */
> +};
> +
> +static const struct of_device_id intc_irqpin_dt_ids[] = {
> +	{ .compatible = "renesas,intc-irqpin", },
> +	{ .compatible = "renesas,intc-irqpin-r8a7779",
> +	  .data = &intc_irqpin_irlm_r8a7779 },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, intc_irqpin_dt_ids);
> +
>  static int intc_irqpin_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
>  	struct renesas_intc_irqpin_config *pdata = dev->platform_data;
> +	const struct of_device_id *of_id;
>  	struct intc_irqpin_priv *p;
>  	struct intc_irqpin_iomem *i;
>  	struct resource *io[INTC_IRQPIN_REG_NR];
> @@ -391,10 +411,11 @@ static int intc_irqpin_probe(struct plat
>  	pm_runtime_enable(dev);
>  	pm_runtime_get_sync(dev);
>  
> -	/* get hold of manadatory IOMEM */
> +	/* get hold of register banks */
> +	memset(io, 0, sizeof(io));
>  	for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
>  		io[k] = platform_get_resource(pdev, IORESOURCE_MEM, k);
> -		if (!io[k]) {
> +		if (!io[k] && k < INTC_IRQPIN_REG_NR_MANDATORY) {
>  			dev_err(dev, "not enough IOMEM resources\n");
>  			ret = -EINVAL;
>  			goto err0;
> @@ -422,6 +443,10 @@ static int intc_irqpin_probe(struct plat
>  	for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
>  		i = &p->iomem[k];
>  
> +		/* handle optional registers */
> +		if (!io[k])
> +			continue;
> +
>  		switch (resource_size(io[k])) {
>  		case 1:
>  			i->width = 8;
> @@ -448,6 +473,19 @@ static int intc_irqpin_probe(struct plat
>  		}
>  	}
>  
> +	/* configure "individual IRQ mode" where needed */
> +	of_id = of_match_device(intc_irqpin_dt_ids, dev);
> +	if (of_id && of_id->data) {
> +		const struct intc_irqpin_irlm_config *irlm_config = of_id->data;
> +
> +		if (io[INTC_IRQPIN_REG_IRLM])
> +			intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_IRLM,
> +						      irlm_config->irlm_bit,
> +						      1, 1);
> +		else
> +			dev_warn(dev, "unable to select IRLM mode\n");

What was the default behavior of the arch code before the DT binding
change?  Should that action be performed here?

thx,

Jason.

> +	}
> +
>  	/* mask all interrupts using priority */
>  	for (k = 0; k < p->number_of_irqs; k++)
>  		intc_irqpin_mask_unmask_prio(p, k, 1);
> @@ -550,12 +588,6 @@ static int intc_irqpin_remove(struct pla
>  	return 0;
>  }
>  
> -static const struct of_device_id intc_irqpin_dt_ids[] = {
> -	{ .compatible = "renesas,intc-irqpin", },
> -	{},
> -};
> -MODULE_DEVICE_TABLE(of, intc_irqpin_dt_ids);
> -
>  static struct platform_driver intc_irqpin_device_driver = {
>  	.probe		= intc_irqpin_probe,
>  	.remove		= intc_irqpin_remove,