[PATCH v3 06/17] irqchip/irq-mvebu-icu: switch to regmap
From: Marc Zyngier <hidden>
Date: 2018-06-28 12:05:05
Also in:
linux-devicetree
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?
quoted hunk ↗ jump to hunk
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> --- 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?
quoted hunk ↗ jump to hunk
} 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...