diff options
Diffstat (limited to 'drivers/irqchip/irq-vf610-mscm-ir.c')
| -rw-r--r-- | drivers/irqchip/irq-vf610-mscm-ir.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-vf610-mscm-ir.c b/drivers/irqchip/irq-vf610-mscm-ir.c new file mode 100644 index 000000000000..9521057d4744 --- /dev/null +++ b/drivers/irqchip/irq-vf610-mscm-ir.c @@ -0,0 +1,212 @@ +/* + * Copyright (C) 2014-2015 Toradex AG + * Author: Stefan Agner <stefan@agner.ch> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * + * IRQ chip driver for MSCM interrupt router available on Vybrid SoC's. + * The interrupt router is between the CPU's interrupt controller and the + * peripheral. The router allows to route the peripheral interrupts to + * one of the two available CPU's on Vybrid VF6xx SoC's (Cortex-A5 or + * Cortex-M4). The router will be configured transparently on a IRQ + * request. + * + * o All peripheral interrupts of the Vybrid SoC can be routed to + * CPU 0, CPU 1 or both. The routing is useful for dual-core + * variants of Vybrid SoC such as VF6xx. This driver routes the + * requested interrupt to the CPU currently running on. + * + * o It is required to setup the interrupt router even on single-core + * variants of Vybrid. + */ + +#include <linux/cpu_pm.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> +#include <linux/mfd/syscon.h> +#include <dt-bindings/interrupt-controller/arm-gic.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/slab.h> +#include <linux/regmap.h> + +#include "irqchip.h" + +#define MSCM_CPxNUM 0x4 + +#define MSCM_IRSPRC(n) (0x80 + 2 * (n)) +#define MSCM_IRSPRC_CPEN_MASK 0x3 + +#define MSCM_IRSPRC_NUM 112 + +struct vf610_mscm_ir_chip_data { + void __iomem *mscm_ir_base; + u16 cpu_mask; + u16 saved_irsprc[MSCM_IRSPRC_NUM]; +}; + +static struct vf610_mscm_ir_chip_data *mscm_ir_data; + +static inline void vf610_mscm_ir_save(struct vf610_mscm_ir_chip_data *data) +{ + int i; + + for (i = 0; i < MSCM_IRSPRC_NUM; i++) + data->saved_irsprc[i] = readw_relaxed(data->mscm_ir_base + MSCM_IRSPRC(i)); +} + +static inline void vf610_mscm_ir_restore(struct vf610_mscm_ir_chip_data *data) +{ + int i; + + for (i = 0; i < MSCM_IRSPRC_NUM; i++) + writew_relaxed(data->saved_irsprc[i], data->mscm_ir_base + MSCM_IRSPRC(i)); +} + +static int vf610_mscm_ir_notifier(struct notifier_block *self, + unsigned long cmd, void *v) +{ + switch (cmd) { + case CPU_CLUSTER_PM_ENTER: + vf610_mscm_ir_save(mscm_ir_data); + break; + case CPU_CLUSTER_PM_ENTER_FAILED: + case CPU_CLUSTER_PM_EXIT: + vf610_mscm_ir_restore(mscm_ir_data); + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block mscm_ir_notifier_block = { + .notifier_call = vf610_mscm_ir_notifier, +}; + +static void vf610_mscm_ir_enable(struct irq_data *data) +{ + irq_hw_number_t hwirq = data->hwirq; + struct vf610_mscm_ir_chip_data *chip_data = data->chip_data; + u16 irsprc; + + irsprc = readw_relaxed(chip_data->mscm_ir_base + MSCM_IRSPRC(hwirq)); + irsprc &= MSCM_IRSPRC_CPEN_MASK; + + WARN_ON(irsprc & ~chip_data->cpu_mask); + + writew_relaxed(chip_data->cpu_mask, + chip_data->mscm_ir_base + MSCM_IRSPRC(hwirq)); + + irq_chip_unmask_parent(data); +} + +static void vf610_mscm_ir_disable(struct irq_data *data) +{ + irq_hw_number_t hwirq = data->hwirq; + struct vf610_mscm_ir_chip_data *chip_data = data->chip_data; + + writew_relaxed(0x0, chip_data->mscm_ir_base + MSCM_IRSPRC(hwirq)); + + irq_chip_mask_parent(data); +} + +static struct irq_chip vf610_mscm_ir_irq_chip = { + .name = "mscm-ir", + .irq_mask = irq_chip_mask_parent, + .irq_unmask = irq_chip_unmask_parent, + .irq_eoi = irq_chip_eoi_parent, + .irq_enable = vf610_mscm_ir_enable, + .irq_disable = vf610_mscm_ir_disable, + .irq_retrigger = irq_chip_retrigger_hierarchy, + .irq_set_affinity = irq_chip_set_affinity_parent, +}; + +static int vf610_mscm_ir_domain_alloc(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs, void *arg) +{ + int i; + irq_hw_number_t hwirq; + struct of_phandle_args *irq_data = arg; + struct of_phandle_args gic_data; + + if (irq_data->args_count != 2) + return -EINVAL; + + hwirq = irq_data->args[0]; + for (i = 0; i < nr_irqs; i++) + irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i, + &vf610_mscm_ir_irq_chip, + domain->host_data); + + gic_data.np = domain->parent->of_node; + gic_data.args_count = 3; + gic_data.args[0] = GIC_SPI; + gic_data.args[1] = irq_data->args[0]; + gic_data.args[2] = irq_data->args[1]; + return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, &gic_data); +} + +static const struct irq_domain_ops mscm_irq_domain_ops = { + .xlate = irq_domain_xlate_twocell, + .alloc = vf610_mscm_ir_domain_alloc, + .free = irq_domain_free_irqs_common, +}; + +static int __init vf610_mscm_ir_of_init(struct device_node *node, + struct device_node *parent) +{ + struct irq_domain *domain, *domain_parent; + struct regmap *mscm_cp_regmap; + int ret, cpuid; + + domain_parent = irq_find_host(parent); + if (!domain_parent) { + pr_err("vf610_mscm_ir: interrupt-parent not found\n"); + return -EINVAL; + } + + mscm_ir_data = kzalloc(sizeof(*mscm_ir_data), GFP_KERNEL); + if (!mscm_ir_data) + return -ENOMEM; + + mscm_ir_data->mscm_ir_base = of_io_request_and_map(node, 0, "mscm-ir"); + + if (!mscm_ir_data->mscm_ir_base) { + pr_err("vf610_mscm_ir: unable to map mscm register\n"); + ret = -ENOMEM; + goto out_free; + } + + mscm_cp_regmap = syscon_regmap_lookup_by_phandle(node, "fsl,cpucfg"); + if (IS_ERR(mscm_cp_regmap)) { + ret = PTR_ERR(mscm_cp_regmap); + pr_err("vf610_mscm_ir: regmap lookup for cpucfg failed\n"); + goto out_unmap; + } + + regmap_read(mscm_cp_regmap, MSCM_CPxNUM, &cpuid); + mscm_ir_data->cpu_mask = 0x1 << cpuid; + + domain = irq_domain_add_hierarchy(domain_parent, 0, + MSCM_IRSPRC_NUM, node, + &mscm_irq_domain_ops, mscm_ir_data); + if (!domain) { + ret = -ENOMEM; + goto out_unmap; + } + + cpu_pm_register_notifier(&mscm_ir_notifier_block); + + return 0; + +out_unmap: + iounmap(mscm_ir_data->mscm_ir_base); +out_free: + kfree(mscm_ir_data); + return ret; +} +IRQCHIP_DECLARE(vf610_mscm_ir, "fsl,vf610-mscm-ir", vf610_mscm_ir_of_init); |