Re: [PATCH v3 3/5] irqchip: ocelot: Add support for Luton platforms

From: Marc Zyngier
Date: Wed Nov 18 2020 - 07:38:36 EST


On 2020-11-16 16:24, Gregory CLEMENT wrote:
This patch extends irqchip driver for oceleot to be used with an other
vcoreiii base platform: Luton.

Based on a larger patch from Lars Povlsen <lars.povlsen@xxxxxxxxxxxxx>
Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxx>
---
drivers/irqchip/irq-mscc-ocelot.c | 145 +++++++++++++++++++++++++-----
1 file changed, 123 insertions(+), 22 deletions(-)

diff --git a/drivers/irqchip/irq-mscc-ocelot.c
b/drivers/irqchip/irq-mscc-ocelot.c
index 88143c0b700c..9964800c53c2 100644
--- a/drivers/irqchip/irq-mscc-ocelot.c
+++ b/drivers/irqchip/irq-mscc-ocelot.c
@@ -12,39 +12,115 @@
#include <linux/irqchip/chained_irq.h>
#include <linux/interrupt.h>

-#define ICPU_CFG_INTR_INTR_STICKY 0x10
-#define ICPU_CFG_INTR_INTR_ENA 0x18
-#define ICPU_CFG_INTR_INTR_ENA_CLR 0x1c
-#define ICPU_CFG_INTR_INTR_ENA_SET 0x20
-#define ICPU_CFG_INTR_DST_INTR_IDENT(x) (0x38 + 0x4 * (x))
-#define ICPU_CFG_INTR_INTR_TRIGGER(x) (0x5c + 0x4 * (x))
-
-#define OCELOT_NR_IRQ 24
+#define ICPU_CFG_INTR_DST_INTR_IDENT(_p, x) (_p->reg_off_ident + 0x4 * (x))
+#define ICPU_CFG_INTR_INTR_TRIGGER(_p, x) (_p->reg_off_trigger + 0x4 * (x))
+
+#define FLAGS_NEED_INIT_ENABLE BIT(0)
+#define FLAGS_FORCE_LUTON_STYLE BIT(1)
+#define FLAGS_HAS_TRIGGER BIT(2)
+
+struct chip_props {
+ u32 flags;
+ u32 reg_off_sticky;
+ u32 reg_off_ena;
+ u32 reg_off_ena_clr;
+ u32 reg_off_ena_set;
+ u32 reg_off_ident;
+ u32 reg_off_trigger;
+ u32 reg_off_force;
+ u32 reg_off_ena_irq0;

Do all these fields need to be u32s?

+ u32 n_irq;
+};
+
+static const struct chip_props ocelot_props = {
+ .flags = FLAGS_HAS_TRIGGER,
+ .reg_off_sticky = 0x10,
+ .reg_off_ena = 0x18,
+ .reg_off_ena_clr = 0x1c,
+ .reg_off_ena_set = 0x20,
+ .reg_off_ident = 0x38,
+ .reg_off_trigger = 0x5c,
+ .reg_off_force = 0xc,
+ .n_irq = 24,
+};
+
+static const struct chip_props luton_props = {
+ .flags = FLAGS_NEED_INIT_ENABLE |
+ FLAGS_FORCE_LUTON_STYLE,

LUTON_STYLE doesn't quite convey the idea of what this implies.
Please use a name that actually means something (other than the
city north of London). And force what exactly?

+ .reg_off_sticky = 0,
+ .reg_off_ena = 0x4,
+ .reg_off_ena_clr = 0x8,
+ .reg_off_ena_set = 0xc,
+ .reg_off_ident = 0x18,
+ .reg_off_trigger = 0,

If this field doesn't exist (because the matching flag isn't set), don't
list it.

+ .reg_off_force = 0x38,
+ .reg_off_ena_irq0 = 0x14,
+ .n_irq = 28,
+};

Please split this patch in two: rework the Ocelot driver to the "new"
style in one patch, then introduce new platform in another.


static void ocelot_irq_unmask(struct irq_data *data)
{
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
+ struct irq_domain *d = data->domain;
+ struct chip_props *p = d->host_data;
struct irq_chip_type *ct = irq_data_get_chip_type(data);
unsigned int mask = data->mask;
u32 val;

irq_gc_lock(gc);
- val = irq_reg_readl(gc, ICPU_CFG_INTR_INTR_TRIGGER(0)) |
- irq_reg_readl(gc, ICPU_CFG_INTR_INTR_TRIGGER(1));
- if (!(val & mask))
- irq_reg_writel(gc, mask, ICPU_CFG_INTR_INTR_STICKY);
+ if (p->flags & FLAGS_HAS_TRIGGER) {
+ val = irq_reg_readl(gc, ICPU_CFG_INTR_INTR_TRIGGER(p, 0)) |
+ irq_reg_readl(gc, ICPU_CFG_INTR_INTR_TRIGGER(p, 1));
+ if (!(val & mask))
+ irq_reg_writel(gc, mask, p->reg_off_sticky);
+ }

*ct->mask_cache &= ~mask;
- irq_reg_writel(gc, mask, ICPU_CFG_INTR_INTR_ENA_SET);
+ irq_reg_writel(gc, mask, p->reg_off_ena_set);
irq_gc_unlock(gc);
}

+static void luton_irq_force(struct irq_data *data,
+ struct irq_chip_generic *gc,
+ struct chip_props *p)
+{
+ int off = p->reg_off_force + (data->hwirq * sizeof(u32));
+ u32 val = irq_reg_readl(gc, off);
+
+ irq_reg_writel(gc, val | BIT(3), off);
+}
+
+static int ocelot_irq_force(struct irq_data *data,
+ enum irqchip_irq_state which, bool state)

Please use a name that matches the same of the API.

+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
+ struct irq_domain *d = data->domain;
+ struct chip_props *p = d->host_data;
+ int ret = -EINVAL;
+
+ /* Only supports triggering */
+ if ((which == IRQCHIP_STATE_PENDING ||
+ which == IRQCHIP_STATE_ACTIVE) &&

PENDING and ACTIVE are two very different things, and yet you handle
them the same way. Which one does your interrupt controller support?

+ state && p->reg_off_force) {
+ if (p->flags & FLAGS_FORCE_LUTON_STYLE)
+ /* Config register style */
+ luton_irq_force(data, gc, p);
+ else
+ /* New, bitmask style */
+ irq_reg_writel(gc, data->mask, p->reg_off_force);
+ ret = 0;
+ }
+
+ return ret;
+}
+
static void ocelot_irq_handler(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
struct irq_domain *d = irq_desc_get_handler_data(desc);
+ struct chip_props *p = d->host_data;
struct irq_chip_generic *gc = irq_get_domain_generic_chip(d, 0);
- u32 reg = irq_reg_readl(gc, ICPU_CFG_INTR_DST_INTR_IDENT(0));
+ u32 reg = irq_reg_readl(gc, ICPU_CFG_INTR_DST_INTR_IDENT(p, 0));

chained_irq_enter(chip, desc);

@@ -58,25 +134,28 @@ static void ocelot_irq_handler(struct irq_desc *desc)
chained_irq_exit(chip, desc);
}

-static int __init ocelot_irq_init(struct device_node *node,
- struct device_node *parent)
+static int __init vcoreiii_irq_init(struct device_node *node,
+ struct device_node *parent,
+ const struct chip_props *p)
{
struct irq_domain *domain;
struct irq_chip_generic *gc;
int parent_irq, ret;

+ pr_info("%s: Load, %d irqs\n", node->name, p->n_irq);

If you must print something, use %pOFn, just like in the rest of the driver.

+
parent_irq = irq_of_parse_and_map(node, 0);
if (!parent_irq)
return -EINVAL;

- domain = irq_domain_add_linear(node, OCELOT_NR_IRQ,
+ domain = irq_domain_add_linear(node, p->n_irq,
&irq_generic_chip_ops, NULL);
if (!domain) {
pr_err("%pOFn: unable to add irq domain\n", node);
return -ENOMEM;
}

- ret = irq_alloc_domain_generic_chips(domain, OCELOT_NR_IRQ, 1,
+ ret = irq_alloc_domain_generic_chips(domain, p->n_irq, 1,
"icpu", handle_level_irq,
0, 0, 0);
if (ret) {
@@ -92,16 +171,23 @@ static int __init ocelot_irq_init(struct device_node *node,
goto err_gc_free;
}

- gc->chip_types[0].regs.ack = ICPU_CFG_INTR_INTR_STICKY;
- gc->chip_types[0].regs.mask = ICPU_CFG_INTR_INTR_ENA_CLR;
+ gc->chip_types[0].regs.ack = p->reg_off_sticky;
+ gc->chip_types[0].regs.mask = p->reg_off_ena_clr;
gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
gc->chip_types[0].chip.irq_mask = irq_gc_mask_set_bit;
gc->chip_types[0].chip.irq_unmask = ocelot_irq_unmask;
+ gc->chip_types[0].chip.irq_unmask = ocelot_irq_unmask;
+ gc->chip_types[0].chip.irq_set_irqchip_state = ocelot_irq_force;

/* Mask and ack all interrupts */
- irq_reg_writel(gc, 0, ICPU_CFG_INTR_INTR_ENA);
- irq_reg_writel(gc, 0xffffffff, ICPU_CFG_INTR_INTR_STICKY);
+ irq_reg_writel(gc, 0, p->reg_off_ena);
+ irq_reg_writel(gc, 0xffffffff, p->reg_off_sticky);
+
+ /* Overall init */
+ if (p->flags & FLAGS_NEED_INIT_ENABLE)
+ irq_reg_writel(gc, BIT(0), p->reg_off_ena_irq0);

+ domain->host_data = (void *)p;

Useless cast.

irq_set_chained_handler_and_data(parent_irq, ocelot_irq_handler,
domain);

@@ -115,4 +201,19 @@ static int __init ocelot_irq_init(struct device_node *node,

return ret;
}
+
+static int __init ocelot_irq_init(struct device_node *node,
+ struct device_node *parent)
+{
+ return vcoreiii_irq_init(node, parent, &ocelot_props);
+}
+
IRQCHIP_DECLARE(ocelot_icpu, "mscc,ocelot-icpu-intr", ocelot_irq_init);
+
+static int __init luton_irq_init(struct device_node *node,
+ struct device_node *parent)
+{
+ return vcoreiii_irq_init(node, parent, &luton_props);
+}
+
+IRQCHIP_DECLARE(luton_icpu, "mscc,luton-icpu-intr", luton_irq_init);

Thanks,

M.
--
Jazz is not dead. It just smells funny...