[PATCH v2 2/9] irqchip: stm32: add multi-bank management

Ludovic BARRE ludovic.barre at st.com
Fri Oct 27 01:10:55 PDT 2017


Hi Julien

thank for your review

On 10/26/2017 04:36 PM, Julien Thierry wrote:
> Hi Ludovic,
> 
> On 25/10/17 18:10, Ludovic Barre wrote:
>> From: Ludovic Barre <ludovic.barre at st.com>
>>
>> -Prepare to manage multi-bank of external interrupts
>> (N banks of 32 inputs).
>> -Prepare to manage registers offsets by compatible
>> (registers offsets could be different follow per stm32 platform).
>>
>> Signed-off-by: Ludovic Barre <ludovic.barre at st.com>
>> ---
>>   drivers/irqchip/irq-stm32-exti.c | 151 
>> +++++++++++++++++++++++++++------------
>>   1 file changed, 105 insertions(+), 46 deletions(-)
>>
>> diff --git a/drivers/irqchip/irq-stm32-exti.c 
>> b/drivers/irqchip/irq-stm32-exti.c
>> index 45363ff..6b4109b 100644
>> --- a/drivers/irqchip/irq-stm32-exti.c
>> +++ b/drivers/irqchip/irq-stm32-exti.c
>> @@ -14,27 +14,66 @@
>>   #include <linux/of_address.h>
>>   #include <linux/of_irq.h>
>> -#define EXTI_IMR    0x0
>> -#define EXTI_EMR    0x4
>> -#define EXTI_RTSR    0x8
>> -#define EXTI_FTSR    0xc
>> -#define EXTI_SWIER    0x10
>> -#define EXTI_PR        0x14
>> +#define IRQS_PER_BANK 32
>> +
>> +struct stm32_exti_bank {
>> +    u32 imr_ofst;
>> +    u32 emr_ofst;
>> +    u32 rtsr_ofst;
>> +    u32 ftsr_ofst;
>> +    u32 swier_ofst;
>> +    u32 pr_ofst;
>> +};
>> +
>> +static const struct stm32_exti_bank stm32f4xx_exti_b1 = {
>> +    .imr_ofst    = 0x00,
>> +    .emr_ofst    = 0x04,
>> +    .rtsr_ofst    = 0x08,
>> +    .ftsr_ofst    = 0x0C,
>> +    .swier_ofst    = 0x10,
>> +    .pr_ofst    = 0x14,
>> +};
>> +
>> +static const struct stm32_exti_bank *stm32f4xx_exti_banks[] = {
>> +    &stm32f4xx_exti_b1,
>> +};
>> +
>> +static unsigned long stm32_exti_pending(struct irq_chip_generic *gc)
>> +{
>> +    const struct stm32_exti_bank *stm32_bank = gc->private;
>> +
>> +    return irq_reg_readl(gc, stm32_bank->pr_ofst);
>> +}
>> +
>> +static void stm32_exti_irq_ack(struct irq_chip_generic *gc, u32 mask)
>> +{
>> +    const struct stm32_exti_bank *stm32_bank = gc->private;
>> +
>> +    irq_reg_writel(gc, mask, stm32_bank->pr_ofst);
>> +}
>>   static void stm32_irq_handler(struct irq_desc *desc)
>>   {
>>       struct irq_domain *domain = irq_desc_get_handler_data(desc);
>> -    struct irq_chip_generic *gc = domain->gc->gc[0];
>>       struct irq_chip *chip = irq_desc_get_chip(desc);
>> +    unsigned int virq, nbanks = domain->gc->num_chips;
>> +    struct irq_chip_generic *gc;
>> +    const struct stm32_exti_bank *stm32_bank;
>>       unsigned long pending;
>> -    int n;
>> +    int n, i, irq_base = 0;
>>       chained_irq_enter(chip, desc);
>> -    while ((pending = irq_reg_readl(gc, EXTI_PR))) {
>> -        for_each_set_bit(n, &pending, BITS_PER_LONG) {
>> -            generic_handle_irq(irq_find_mapping(domain, n));
>> -            irq_reg_writel(gc, BIT(n), EXTI_PR);
>> +    for (i = 0; i < nbanks; i++, irq_base += IRQS_PER_BANK) {
>> +        gc = irq_get_domain_generic_chip(domain, irq_base);
>> +        stm32_bank = gc->private;
>> +
>> +        while ((pending = stm32_exti_pending(gc))) {
>> +            for_each_set_bit(n, &pending, IRQS_PER_BANK) {
>> +                virq = irq_find_mapping(domain, irq_base + n);
>> +                generic_handle_irq(virq);
>> +                stm32_exti_irq_ack(gc, BIT(n));
>> +            }
>>           }
>>       }
>> @@ -44,13 +83,14 @@ static void stm32_irq_handler(struct irq_desc *desc)
>>   static int stm32_irq_set_type(struct irq_data *data, unsigned int type)
>>   {
>>       struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
>> -    int pin = data->hwirq;
>> +    const struct stm32_exti_bank *stm32_bank = gc->private;
>> +    int pin = data->hwirq % IRQS_PER_BANK;
>>       u32 rtsr, ftsr;
>>       irq_gc_lock(gc);
>> -    rtsr = irq_reg_readl(gc, EXTI_RTSR);
>> -    ftsr = irq_reg_readl(gc, EXTI_FTSR);
>> +    rtsr = irq_reg_readl(gc, stm32_bank->rtsr_ofst);
>> +    ftsr = irq_reg_readl(gc, stm32_bank->ftsr_ofst);
>>       switch (type) {
>>       case IRQ_TYPE_EDGE_RISING:
>> @@ -70,8 +110,8 @@ static int stm32_irq_set_type(struct irq_data 
>> *data, unsigned int type)
>>           return -EINVAL;
>>       }
>> -    irq_reg_writel(gc, rtsr, EXTI_RTSR);
>> -    irq_reg_writel(gc, ftsr, EXTI_FTSR);
>> +    irq_reg_writel(gc, rtsr, stm32_bank->rtsr_ofst);
>> +    irq_reg_writel(gc, ftsr, stm32_bank->ftsr_ofst);
>>       irq_gc_unlock(gc);
>> @@ -81,17 +121,18 @@ static int stm32_irq_set_type(struct irq_data 
>> *data, unsigned int type)
>>   static int stm32_irq_set_wake(struct irq_data *data, unsigned int on)
>>   {
>>       struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
>> -    int pin = data->hwirq;
>> +    const struct stm32_exti_bank *stm32_bank = gc->private;
>> +    int pin = data->hwirq % IRQS_PER_BANK;
>>       u32 emr;
>>       irq_gc_lock(gc);
>> -    emr = irq_reg_readl(gc, EXTI_EMR);
>> +    emr = irq_reg_readl(gc, stm32_bank->emr_ofst);
>>       if (on)
>>           emr |= BIT(pin);
>>       else
>>           emr &= ~BIT(pin);
>> -    irq_reg_writel(gc, emr, EXTI_EMR);
>> +    irq_reg_writel(gc, emr, stm32_bank->emr_ofst);
>>       irq_gc_unlock(gc);
>> @@ -101,11 +142,12 @@ static int stm32_irq_set_wake(struct irq_data 
>> *data, unsigned int on)
>>   static int stm32_exti_alloc(struct irq_domain *d, unsigned int virq,
>>                   unsigned int nr_irqs, void *data)
>>   {
>> -    struct irq_chip_generic *gc = d->gc->gc[0];
>> +    struct irq_chip_generic *gc;
>>       struct irq_fwspec *fwspec = data;
>>       irq_hw_number_t hwirq;
>>       hwirq = fwspec->param[0];
>> +    gc = irq_get_domain_generic_chip(d, hwirq);
>>       irq_map_generic_chip(d, virq, hwirq);
>>       irq_domain_set_info(d, virq, hwirq, &gc->chip_types->chip, gc,
>> @@ -129,8 +171,9 @@ struct irq_domain_ops irq_exti_domain_ops = {
>>       .free    = stm32_exti_free,
>>   };
>> -static int __init stm32_exti_init(struct device_node *node,
>> -                  struct device_node *parent)
>> +static int
>> +__init stm32_exti_init(const struct stm32_exti_bank **stm32_exti_banks,
>> +               int bank_nr, struct device_node *node)
>>   {
>>       unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
>>       int nr_irqs, nr_exti, ret, i;
>> @@ -144,23 +187,16 @@ static int __init stm32_exti_init(struct 
>> device_node *node,
>>           return -ENOMEM;
>>       }
>> -    /* Determine number of irqs supported */
>> -    writel_relaxed(~0UL, base + EXTI_RTSR);
>> -    nr_exti = fls(readl_relaxed(base + EXTI_RTSR));
>> -    writel_relaxed(0, base + EXTI_RTSR);
>> -
>> -    pr_info("%pOF: %d External IRQs detected\n", node, nr_exti);
>> -
>> -    domain = irq_domain_add_linear(node, nr_exti,
>> +    domain = irq_domain_add_linear(node, bank_nr * IRQS_PER_BANK,
>>                          &irq_exti_domain_ops, NULL);
>>       if (!domain) {
>>           pr_err("%s: Could not register interrupt domain.\n",
>> -                node->name);
>> +               node->name);
>>           ret = -ENOMEM;
>>           goto out_unmap;
>>       }
>> -    ret = irq_alloc_domain_generic_chips(domain, nr_exti, 1, "exti",
>> +    ret = irq_alloc_domain_generic_chips(domain, IRQS_PER_BANK, 1, 
>> "exti",
>>                            handle_edge_irq, clr, 0, 0);
>>       if (ret) {
>>           pr_err("%pOF: Could not allocate generic interrupt chip.\n",
>> @@ -168,18 +204,34 @@ static int __init stm32_exti_init(struct 
>> device_node *node,
>>           goto out_free_domain;
>>       }
>> -    gc = domain->gc->gc[0];
>> -    gc->reg_base                         = base;
>> -    gc->chip_types->type               = IRQ_TYPE_EDGE_BOTH;
>> -    gc->chip_types->chip.name          = gc->chip_types[0].chip.name;
>> -    gc->chip_types->chip.irq_ack       = irq_gc_ack_set_bit;
>> -    gc->chip_types->chip.irq_mask      = irq_gc_mask_clr_bit;
>> -    gc->chip_types->chip.irq_unmask    = irq_gc_mask_set_bit;
>> -    gc->chip_types->chip.irq_set_type  = stm32_irq_set_type;
>> -    gc->chip_types->chip.irq_set_wake  = stm32_irq_set_wake;
>> -    gc->chip_types->regs.ack           = EXTI_PR;
>> -    gc->chip_types->regs.mask          = EXTI_IMR;
>> -    gc->chip_types->handler            = handle_edge_irq;
>> +    for (i = 0; i < bank_nr; i++) {
>> +        const struct stm32_exti_bank *stm32_bank = stm32_exti_banks[i];
>> +        u32 irqs_mask;
>> +
>> +        gc = irq_get_domain_generic_chip(domain, i * IRQS_PER_BANK);
>> +
>> +        gc->reg_base = base;
>> +        gc->chip_types->type = IRQ_TYPE_EDGE_BOTH;
>> +        gc->chip_types->chip.name = gc->chip_types[0].chip.name;
> 
> I might be missing something, but what is the point of this line?
indeed these 2 lines:
  gc->chip_types->chip.name = gc->chip_types[0].chip.name
  gc->chip_types->handler = handle_edge_irq;

are not needed, it's done in irq_alloc_domain_generic_chips
> 
>> +        gc->chip_types->chip.irq_ack = irq_gc_ack_set_bit;
>> +        gc->chip_types->chip.irq_mask = irq_gc_mask_clr_bit;
>> +        gc->chip_types->chip.irq_unmask = irq_gc_mask_set_bit;
>> +        gc->chip_types->chip.irq_set_type = stm32_irq_set_type;
>> +        gc->chip_types->chip.irq_set_wake = stm32_irq_set_wake;
>> +        gc->chip_types->regs.ack = stm32_bank->pr_ofst;
>> +        gc->chip_types->regs.mask = stm32_bank->imr_ofst;
>> +        gc->chip_types->handler = handle_edge_irq;
> 
> I believe this is already done by irq_alloc_domain_generic_chips.
> 
> Thanks,
> 



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