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

From: Julien Thierry
Date: Thu Oct 26 2017 - 10:36:15 EST

Hi Ludovic,

On 25/10/17 18:10, Ludovic Barre wrote:
From: Ludovic Barre <ludovic.barre@xxxxxx>

-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@xxxxxx>
---
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?

+ 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,

--
Julien Thierry