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author | Rasmus Villemoes <linux@rasmusvillemoes.dk> | 2019-11-07 13:21:15 +0100 |
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committer | Marc Zyngier <maz@kernel.org> | 2019-11-10 18:47:49 +0000 |
commit | 0dcd9f872769547f336741880bc7e721149c8d0a (patch) | |
tree | 2b027b41535fa923bbf9cf64f5a5fefbc075e816 /drivers | |
parent | 87cd38dfd9e67ffa7c3d3d1a54a2482ed23f1307 (diff) | |
download | linux-0dcd9f872769547f336741880bc7e721149c8d0a.tar.gz linux-0dcd9f872769547f336741880bc7e721149c8d0a.tar.bz2 linux-0dcd9f872769547f336741880bc7e721149c8d0a.zip |
irqchip: Add support for Layerscape external interrupt lines
The LS1021A allows inverting the polarity of six interrupt lines
IRQ[0:5] via the scfg_intpcr register, effectively allowing
IRQ_TYPE_LEVEL_LOW and IRQ_TYPE_EDGE_FALLING for those. We just need to
check the type, set the relevant bit in INTPCR accordingly, and fixup
the type argument before calling the GIC's irq_set_type.
In fact, the power-on-reset value of the INTPCR register on the LS1021A
is so that all six lines have their polarity inverted. Hence any
hardware connected to those lines is unusable without this: If the line
is indeed active low, the generic GIC code will reject an irq spec with
IRQ_TYPE_LEVEL_LOW, while if the line is active high, we must obviously
disable the polarity inversion (writing 0 to the relevant bit) before
unmasking the interrupt.
Some other Layerscape SOCs (LS1043A, LS1046A) have a similar feature,
just with a different number of external interrupt lines (and a
different POR value for the INTPCR register). This driver should be
prepared for supporting those by properly filling out the device tree
node. I have the reference manuals for all three boards, but I've only
tested the driver on an LS1021A.
Unfortunately, the Kconfig symbol ARCH_LAYERSCAPE only exists on
arm64, so do as is done for irq-ls-scfg-msi.c: introduce a new symbol
which is set when either ARCH_LAYERSCAPE or SOC_LS1021A is set.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20191107122115.6244-3-linux@rasmusvillemoes.dk
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/irqchip/Kconfig | 4 | ||||
-rw-r--r-- | drivers/irqchip/Makefile | 1 | ||||
-rw-r--r-- | drivers/irqchip/irq-ls-extirq.c | 197 |
3 files changed, 202 insertions, 0 deletions
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig index ccbb8973a324..bbb323462912 100644 --- a/drivers/irqchip/Kconfig +++ b/drivers/irqchip/Kconfig @@ -370,6 +370,10 @@ config MVEBU_PIC config MVEBU_SEI bool +config LS_EXTIRQ + def_bool y if SOC_LS1021A || ARCH_LAYERSCAPE + select MFD_SYSCON + config LS_SCFG_MSI def_bool y if SOC_LS1021A || ARCH_LAYERSCAPE depends on PCI && PCI_MSI diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile index cc7c43932f16..e806dda690ea 100644 --- a/drivers/irqchip/Makefile +++ b/drivers/irqchip/Makefile @@ -84,6 +84,7 @@ obj-$(CONFIG_MVEBU_ICU) += irq-mvebu-icu.o obj-$(CONFIG_MVEBU_ODMI) += irq-mvebu-odmi.o obj-$(CONFIG_MVEBU_PIC) += irq-mvebu-pic.o obj-$(CONFIG_MVEBU_SEI) += irq-mvebu-sei.o +obj-$(CONFIG_LS_EXTIRQ) += irq-ls-extirq.o obj-$(CONFIG_LS_SCFG_MSI) += irq-ls-scfg-msi.o obj-$(CONFIG_EZNPS_GIC) += irq-eznps.o obj-$(CONFIG_ARCH_ASPEED) += irq-aspeed-vic.o irq-aspeed-i2c-ic.o diff --git a/drivers/irqchip/irq-ls-extirq.c b/drivers/irqchip/irq-ls-extirq.c new file mode 100644 index 000000000000..4d1179fed77c --- /dev/null +++ b/drivers/irqchip/irq-ls-extirq.c @@ -0,0 +1,197 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define pr_fmt(fmt) "irq-ls-extirq: " fmt + +#include <linux/irq.h> +#include <linux/irqchip.h> +#include <linux/irqdomain.h> +#include <linux/of.h> +#include <linux/mfd/syscon.h> +#include <linux/regmap.h> +#include <linux/slab.h> + +#include <dt-bindings/interrupt-controller/arm-gic.h> + +#define MAXIRQ 12 +#define LS1021A_SCFGREVCR 0x200 + +struct ls_extirq_data { + struct regmap *syscon; + u32 intpcr; + bool bit_reverse; + u32 nirq; + struct irq_fwspec map[MAXIRQ]; +}; + +static int +ls_extirq_set_type(struct irq_data *data, unsigned int type) +{ + struct ls_extirq_data *priv = data->chip_data; + irq_hw_number_t hwirq = data->hwirq; + u32 value, mask; + + if (priv->bit_reverse) + mask = 1U << (31 - hwirq); + else + mask = 1U << hwirq; + + switch (type) { + case IRQ_TYPE_LEVEL_LOW: + type = IRQ_TYPE_LEVEL_HIGH; + value = mask; + break; + case IRQ_TYPE_EDGE_FALLING: + type = IRQ_TYPE_EDGE_RISING; + value = mask; + break; + case IRQ_TYPE_LEVEL_HIGH: + case IRQ_TYPE_EDGE_RISING: + value = 0; + break; + default: + return -EINVAL; + } + regmap_update_bits(priv->syscon, priv->intpcr, mask, value); + + return irq_chip_set_type_parent(data, type); +} + +static struct irq_chip ls_extirq_chip = { + .name = "ls-extirq", + .irq_mask = irq_chip_mask_parent, + .irq_unmask = irq_chip_unmask_parent, + .irq_eoi = irq_chip_eoi_parent, + .irq_set_type = ls_extirq_set_type, + .irq_retrigger = irq_chip_retrigger_hierarchy, + .irq_set_affinity = irq_chip_set_affinity_parent, + .flags = IRQCHIP_SET_TYPE_MASKED, +}; + +static int +ls_extirq_domain_alloc(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs, void *arg) +{ + struct ls_extirq_data *priv = domain->host_data; + struct irq_fwspec *fwspec = arg; + irq_hw_number_t hwirq; + + if (fwspec->param_count != 2) + return -EINVAL; + + hwirq = fwspec->param[0]; + if (hwirq >= priv->nirq) + return -EINVAL; + + irq_domain_set_hwirq_and_chip(domain, virq, hwirq, &ls_extirq_chip, + priv); + + return irq_domain_alloc_irqs_parent(domain, virq, 1, &priv->map[hwirq]); +} + +static const struct irq_domain_ops extirq_domain_ops = { + .xlate = irq_domain_xlate_twocell, + .alloc = ls_extirq_domain_alloc, + .free = irq_domain_free_irqs_common, +}; + +static int +ls_extirq_parse_map(struct ls_extirq_data *priv, struct device_node *node) +{ + const __be32 *map; + u32 mapsize; + int ret; + + map = of_get_property(node, "interrupt-map", &mapsize); + if (!map) + return -ENOENT; + if (mapsize % sizeof(*map)) + return -EINVAL; + mapsize /= sizeof(*map); + + while (mapsize) { + struct device_node *ipar; + u32 hwirq, intsize, j; + + if (mapsize < 3) + return -EINVAL; + hwirq = be32_to_cpup(map); + if (hwirq >= MAXIRQ) + return -EINVAL; + priv->nirq = max(priv->nirq, hwirq + 1); + + ipar = of_find_node_by_phandle(be32_to_cpup(map + 2)); + map += 3; + mapsize -= 3; + if (!ipar) + return -EINVAL; + priv->map[hwirq].fwnode = &ipar->fwnode; + ret = of_property_read_u32(ipar, "#interrupt-cells", &intsize); + if (ret) + return ret; + + if (intsize > mapsize) + return -EINVAL; + + priv->map[hwirq].param_count = intsize; + for (j = 0; j < intsize; ++j) + priv->map[hwirq].param[j] = be32_to_cpup(map++); + mapsize -= intsize; + } + return 0; +} + +static int __init +ls_extirq_of_init(struct device_node *node, struct device_node *parent) +{ + + struct irq_domain *domain, *parent_domain; + struct ls_extirq_data *priv; + int ret; + + parent_domain = irq_find_host(parent); + if (!parent_domain) { + pr_err("Cannot find parent domain\n"); + return -ENODEV; + } + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->syscon = syscon_node_to_regmap(node->parent); + if (IS_ERR(priv->syscon)) { + ret = PTR_ERR(priv->syscon); + pr_err("Failed to lookup parent regmap\n"); + goto out; + } + ret = of_property_read_u32(node, "reg", &priv->intpcr); + if (ret) { + pr_err("Missing INTPCR offset value\n"); + goto out; + } + + ret = ls_extirq_parse_map(priv, node); + if (ret) + goto out; + + if (of_device_is_compatible(node, "fsl,ls1021a-extirq")) { + u32 revcr; + + ret = regmap_read(priv->syscon, LS1021A_SCFGREVCR, &revcr); + if (ret) + goto out; + priv->bit_reverse = (revcr != 0); + } + + domain = irq_domain_add_hierarchy(parent_domain, 0, priv->nirq, node, + &extirq_domain_ops, priv); + if (!domain) + ret = -ENOMEM; + +out: + if (ret) + kfree(priv); + return ret; +} + +IRQCHIP_DECLARE(ls1021a_extirq, "fsl,ls1021a-extirq", ls_extirq_of_init); |