On 22/06/18 16:14, Miquel Raynal wrote:
> Before splitting the code to support multiple platform devices to
> be probed (one for the ICU, one per interrupt group), let's switch to
> regmap first by creating one in the ->probe().
What's the benefit of doing so? I assume that has to do with supporting
multiple devices that share an MMIO range?
>
> Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
> ---
> drivers/irqchip/irq-mvebu-icu.c | 45 +++++++++++++++++++++++++++--------------
> 1 file changed, 30 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/irqchip/irq-mvebu-icu.c b/drivers/irqchip/irq-mvebu-icu.c
> index 0f2655d7f19e..3694c0d73c0d 100644
> --- a/drivers/irqchip/irq-mvebu-icu.c
> +++ b/drivers/irqchip/irq-mvebu-icu.c
> @@ -18,6 +18,8 @@
> #include <linux/of_irq.h>
> #include <linux/of_platform.h>
> #include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/mfd/syscon.h>
>
> #include <dt-bindings/interrupt-controller/mvebu-icu.h>
>
> @@ -38,7 +40,7 @@
>
> struct mvebu_icu {
> struct irq_chip irq_chip;
> - void __iomem *base;
> + struct regmap *regmap;
> struct irq_domain *domain;
> struct device *dev;
> atomic_t initialized;
> @@ -56,10 +58,10 @@ static void mvebu_icu_init(struct mvebu_icu *icu, struct msi_msg *msg)
> return;
>
> /* Set Clear/Set ICU SPI message address in AP */
> - writel_relaxed(msg[0].address_hi, icu->base + ICU_SETSPI_NSR_AH);
> - writel_relaxed(msg[0].address_lo, icu->base + ICU_SETSPI_NSR_AL);
> - writel_relaxed(msg[1].address_hi, icu->base + ICU_CLRSPI_NSR_AH);
> - writel_relaxed(msg[1].address_lo, icu->base + ICU_CLRSPI_NSR_AL);
> + regmap_write(icu->regmap, ICU_SETSPI_NSR_AH, msg[0].address_hi);
> + regmap_write(icu->regmap, ICU_SETSPI_NSR_AL, msg[0].address_lo);
> + regmap_write(icu->regmap, ICU_CLRSPI_NSR_AH, msg[1].address_hi);
> + regmap_write(icu->regmap, ICU_CLRSPI_NSR_AL, msg[1].address_lo);
Isn't this a change in the way we write things to the MMIO registers?
You're now trading a writel_relaxed for a writel, plus some locking...
Talking about which: Are you always in a context where you can take that
lock? The bit of documentation I've just read seems to imply that the
default lock is a mutex. Is that always safe? My guess is that it isn't,
and any callback that can end-up here after having taken something like
the desc lock is going to blow in your face.
Have you tried lockdep?
> }
>
> static void mvebu_icu_write_msg(struct msi_desc *desc, struct msi_msg *msg)
> @@ -82,7 +84,7 @@ static void mvebu_icu_write_msg(struct msi_desc *desc, struct msi_msg *msg)
> icu_int = 0;
> }
>
> - writel_relaxed(icu_int, icu->base + ICU_INT_CFG(d->hwirq));
> + regmap_write(icu->regmap, ICU_INT_CFG(d->hwirq), icu_int);
>
> /*
> * The SATA unit has 2 ports, and a dedicated ICU entry per
> @@ -94,10 +96,10 @@ static void mvebu_icu_write_msg(struct msi_desc *desc, struct msi_msg *msg)
> * configured (regardless of which port is actually in use).
> */
> if (d->hwirq == ICU_SATA0_ICU_ID || d->hwirq == ICU_SATA1_ICU_ID) {
> - writel_relaxed(icu_int,
> - icu->base + ICU_INT_CFG(ICU_SATA0_ICU_ID));
> - writel_relaxed(icu_int,
> - icu->base + ICU_INT_CFG(ICU_SATA1_ICU_ID));
> + regmap_write(icu->regmap, ICU_INT_CFG(ICU_SATA0_ICU_ID),
> + icu_int);
> + regmap_write(icu->regmap, ICU_INT_CFG(ICU_SATA1_ICU_ID),
> + icu_int);
> }
> }
>
> @@ -204,12 +206,20 @@ static const struct irq_domain_ops mvebu_icu_domain_ops = {
> .free = mvebu_icu_irq_domain_free,
> };
>
> +static struct regmap_config mvebu_icu_regmap_config = {
> + .reg_bits = 32,
> + .val_bits = 32,
> + .reg_stride = 4,
> + .name = "mvebu_icu",
> +};
> +
> static int mvebu_icu_probe(struct platform_device *pdev)
> {
> struct mvebu_icu *icu;
> struct device_node *node = pdev->dev.of_node;
> struct device_node *gicp_dn;
> struct resource *res;
> + void __iomem *regs;
> int i;
>
> icu = devm_kzalloc(&pdev->dev, sizeof(struct mvebu_icu),
> @@ -220,12 +230,17 @@ static int mvebu_icu_probe(struct platform_device *pdev)
> icu->dev = &pdev->dev;
>
> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> - icu->base = devm_ioremap_resource(&pdev->dev, res);
> - if (IS_ERR(icu->base)) {
> + regs = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(regs)) {
> dev_err(&pdev->dev, "Failed to map icu base address.\n");
> - return PTR_ERR(icu->base);
> + return PTR_ERR(regs);
> }
>
> + icu->regmap = devm_regmap_init_mmio(icu->dev, regs,
> + &mvebu_icu_regmap_config);
> + if (IS_ERR(icu->regmap))
> + return PTR_ERR(icu->regmap);
> +
> icu->irq_chip.name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
> "ICU.%x",
> (unsigned int)res->start);
> @@ -260,11 +275,11 @@ static int mvebu_icu_probe(struct platform_device *pdev)
> for (i = 0 ; i < ICU_MAX_IRQS ; i++) {
> u32 icu_int, icu_grp;
>
> - icu_int = readl_relaxed(icu->base + ICU_INT_CFG(i));
> + regmap_read(icu->regmap, ICU_INT_CFG(i), &icu_int);
> icu_grp = icu_int >> ICU_GROUP_SHIFT;
>
> if (icu_grp == ICU_GRP_NSR)
> - writel_relaxed(0x0, icu->base + ICU_INT_CFG(i));
> + regmap_write(icu->regmap, ICU_INT_CFG(i), 0);
> }
>
> icu->domain =
>
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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