Re: [PATCH v2 3/4] irqchip: irq-mtk-cirq: Move register offsets to const array

AngeloGioacchino Del Regno
2022-11-23T14:57:24Z

Il 23/11/22 14:50, Marc Zyngier ha scritto:
> On Wed, 23 Nov 2022 11:22:48 +0000,
> AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> wrote:
>>
>> In preparation to add support for new SoCs having a different
>> register layout, add an enumeration that documents register
>> offsets and move the definitions for the same to a u32 array;
>>
>> Selecting the right register offsets array is done by adding an
>> of_device_id array containing all of the currently supported
>> compatible strings pointing to the "v1" offsets array (as data):
>> since no devicetree declares the `mediatek,mtk-cirq` compatible
>> without a SoC-specific one, it wasn't necessary to provide any
>> legacy fallback.
>>
>> Every usage of the aforemementioned definitions was changed to
>> get a register address through a newly introduced `mtk_cirq_reg()`
>> accessor.
>>
>> This change brings no functional changes.
>>
>> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
>> ---
>> drivers/irqchip/irq-mtk-cirq.c | 78 ++++++++++++++++++++++++++--------
>> 1 file changed, 61 insertions(+), 17 deletions(-)
>>
>> diff --git a/drivers/irqchip/irq-mtk-cirq.c b/drivers/irqchip/irq-mtk-cirq.c
>> index 9bca0918078e..4d873d2ba0fd 100644
>> --- a/drivers/irqchip/irq-mtk-cirq.c
>> +++ b/drivers/irqchip/irq-mtk-cirq.c
>> @@ -15,14 +15,29 @@
>> #include <linux/slab.h>
>> #include <linux/syscore_ops.h>
>>
>> -#define CIRQ_ACK 0x40
>> -#define CIRQ_MASK_SET 0xc0
>> -#define CIRQ_MASK_CLR 0x100
>> -#define CIRQ_SENS_SET 0x180
>> -#define CIRQ_SENS_CLR 0x1c0
>> -#define CIRQ_POL_SET 0x240
>> -#define CIRQ_POL_CLR 0x280
>> -#define CIRQ_CONTROL 0x300
>> +enum mtk_cirq_reg_index {
>> + CIRQ_STA,
>> + CIRQ_ACK,
>> + CIRQ_MASK_SET,
>> + CIRQ_MASK_CLR,
>> + CIRQ_SENS_SET,
>> + CIRQ_SENS_CLR,
>> + CIRQ_POL_SET,
>> + CIRQ_POL_CLR,
>> + CIRQ_CONTROL
>> +};
>> +
>> +static const u32 mtk_cirq_regs_v1[] = {
>
> Again: this contains offsets, not registers. Consistency matters.
>

Ack.

>> + [CIRQ_STA] = 0x0,
>> + [CIRQ_ACK] = 0x40,
>> + [CIRQ_MASK_SET] = 0xc0,
>> + [CIRQ_MASK_CLR] = 0x100,
>> + [CIRQ_SENS_SET] = 0x180,
>> + [CIRQ_SENS_CLR] = 0x1c0,
>> + [CIRQ_POL_SET] = 0x240,
>> + [CIRQ_POL_CLR] = 0x280,
>> + [CIRQ_CONTROL] = 0x300,
>> +};
>>
>> #define CIRQ_EN 0x1
>> #define CIRQ_EDGE 0x2
>> @@ -32,18 +47,28 @@ struct mtk_cirq_chip_data {
>> void __iomem *base;
>> unsigned int ext_irq_start;
>> unsigned int ext_irq_end;
>> + const u32 *offsets;
>> struct irq_domain *domain;
>> };
>>
>> static struct mtk_cirq_chip_data *cirq_data;
>>
>> -static void mtk_cirq_write_mask(struct irq_data *data, unsigned int offset)
>> +static inline void __iomem *mtk_cirq_reg(struct mtk_cirq_chip_data *chip_data,
>
> Drop the inline. That's for the compiler to figure it out.
>

Will do.

>> + enum mtk_cirq_reg_index idx,
>> + unsigned int cirq_num)
>
> What does cirq_num mean for registers that are not relative to an
> interrupt? Create a separate helper for those.
>
Means literally nothing, so yes I agree, but...

... mtk_cirq_irq_reg(), mtk_cirq_reg() feels too similar and may lead to
confusion while reading the code.

Any advice about a possibly clear-er name?

>> +{
>> + void __iomem *reg = chip_data->base + chip_data->offsets[idx];
>> +
>> + return reg + (cirq_num / 32) * 4;
>> +}
>> +
>> +static void mtk_cirq_write_mask(struct irq_data *data, enum mtk_cirq_reg_index idx)
>> {
>> struct mtk_cirq_chip_data *chip_data = data->chip_data;
>> unsigned int cirq_num = data->hwirq;
>> u32 mask = 1 << (cirq_num % 32);
>>
>> - writel_relaxed(mask, chip_data->base + offset + (cirq_num / 32) * 4);
>> + writel_relaxed(mask, mtk_cirq_reg(chip_data, idx, cirq_num));
>> }
>>
>> static void mtk_cirq_mask(struct irq_data *data)
>> @@ -160,6 +185,7 @@ static const struct irq_domain_ops cirq_domain_ops = {
>> #ifdef CONFIG_PM_SLEEP
>> static int mtk_cirq_suspend(void)
>> {
>> + void __iomem *reg;
>> u32 value, mask;
>> unsigned int irq, hwirq_num;
>> bool pending, masked;
>> @@ -200,31 +226,34 @@ static int mtk_cirq_suspend(void)
>> continue;
>> }
>>
>> + reg = mtk_cirq_reg(cirq_data, CIRQ_ACK, i);
>> mask = 1 << (i % 32);
>> - writel_relaxed(mask, cirq_data->base + CIRQ_ACK + (i / 32) * 4);
>> + writel_relaxed(mask, reg);
>> }
>>
>> /* set edge_only mode, record edge-triggerd interrupts */
>> /* enable cirq */
>> - value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
>> + reg = mtk_cirq_reg(cirq_data, CIRQ_CONTROL, 0);
>> + value = readl_relaxed(reg);
>> value |= (CIRQ_EDGE | CIRQ_EN);
>> - writel_relaxed(value, cirq_data->base + CIRQ_CONTROL);
>> + writel_relaxed(value, reg);
>>
>> return 0;
>> }
>>
>> static void mtk_cirq_resume(void)
>> {
>> + void __iomem *reg = mtk_cirq_reg(cirq_data, CIRQ_CONTROL, 0);
>> u32 value;
>>
>> /* flush recorded interrupts, will send signals to parent controller */
>> - value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
>> - writel_relaxed(value | CIRQ_FLUSH, cirq_data->base + CIRQ_CONTROL);
>> + value = readl_relaxed(reg);
>> + writel_relaxed(value | CIRQ_FLUSH, reg);
>>
>> /* disable cirq */
>> - value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
>> + value = readl_relaxed(reg);
>> value &= ~(CIRQ_EDGE | CIRQ_EN);
>> - writel_relaxed(value, cirq_data->base + CIRQ_CONTROL);
>> + writel_relaxed(value, reg);
>> }
>>
>> static struct syscore_ops mtk_cirq_syscore_ops = {
>> @@ -240,10 +269,18 @@ static void mtk_cirq_syscore_init(void)
>> static inline void mtk_cirq_syscore_init(void) {}
>> #endif
>>
>> +static const struct of_device_id mtk_cirq_of_match[] = {
>
> Can't this be made __initconst?
>

Ack.

>> + { .compatible = "mediatek,mt2701-cirq", .data = &mtk_cirq_regs_v1 },
>> + { .compatible = "mediatek,mt8135-cirq", .data = &mtk_cirq_regs_v1 },
>> + { .compatible = "mediatek,mt8173-cirq", .data = &mtk_cirq_regs_v1 },
>> + { /* sentinel */ }
>> +};
>> +
>> static int __init mtk_cirq_of_init(struct device_node *node,
>> struct device_node *parent)
>> {
>> struct irq_domain *domain, *domain_parent;
>> + const struct of_device_id *match;
>> unsigned int irq_num;
>> int ret;
>>
>> @@ -274,6 +311,13 @@ static int __init mtk_cirq_of_init(struct device_node *node,
>> if (ret)
>> goto out_unmap;
>>
>> + match = of_match_node(mtk_cirq_of_match, node);
>> + if (!match) {
>> + ret = -ENODEV;
>> + goto out_unmap;
>> + }
>
> Can't you perform this before mapping the MMIO region and allocating
> memory? If you must fail, fail early.
>

I was thinking the same, but ultimately chose to aggregate handling that entirely
in one place...

I'll move that as suggested.

Many thanks,
Angelo