diff options
Diffstat (limited to 'drivers/irqchip/irq-or1k-pic.c')
| -rw-r--r-- | drivers/irqchip/irq-or1k-pic.c | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-or1k-pic.c b/drivers/irqchip/irq-or1k-pic.c new file mode 100644 index 000000000..f289ccd95 --- /dev/null +++ b/drivers/irqchip/irq-or1k-pic.c @@ -0,0 +1,176 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> + * Copyright (C) 2014 Stefan Kristansson <stefan.kristiansson@saunalahti.fi> + */ + +#include <linux/irq.h> +#include <linux/irqchip.h> +#include <linux/of.h> +#include <linux/of_irq.h> +#include <linux/of_address.h> + +/* OR1K PIC implementation */ + +struct or1k_pic_dev { + struct irq_chip chip; + irq_flow_handler_t handle; + unsigned long flags; +}; + +/* + * We're a couple of cycles faster than the generic implementations with + * these 'fast' versions. + */ + +static void or1k_pic_mask(struct irq_data *data) +{ + mtspr(SPR_PICMR, mfspr(SPR_PICMR) & ~(1UL << data->hwirq)); +} + +static void or1k_pic_unmask(struct irq_data *data) +{ + mtspr(SPR_PICMR, mfspr(SPR_PICMR) | (1UL << data->hwirq)); +} + +static void or1k_pic_ack(struct irq_data *data) +{ + mtspr(SPR_PICSR, (1UL << data->hwirq)); +} + +static void or1k_pic_mask_ack(struct irq_data *data) +{ + mtspr(SPR_PICMR, mfspr(SPR_PICMR) & ~(1UL << data->hwirq)); + mtspr(SPR_PICSR, (1UL << data->hwirq)); +} + +/* + * There are two oddities with the OR1200 PIC implementation: + * i) LEVEL-triggered interrupts are latched and need to be cleared + * ii) the interrupt latch is cleared by writing a 0 to the bit, + * as opposed to a 1 as mandated by the spec + */ +static void or1k_pic_or1200_ack(struct irq_data *data) +{ + mtspr(SPR_PICSR, mfspr(SPR_PICSR) & ~(1UL << data->hwirq)); +} + +static void or1k_pic_or1200_mask_ack(struct irq_data *data) +{ + mtspr(SPR_PICMR, mfspr(SPR_PICMR) & ~(1UL << data->hwirq)); + mtspr(SPR_PICSR, mfspr(SPR_PICSR) & ~(1UL << data->hwirq)); +} + +static struct or1k_pic_dev or1k_pic_level = { + .chip = { + .name = "or1k-PIC-level", + .irq_unmask = or1k_pic_unmask, + .irq_mask = or1k_pic_mask, + }, + .handle = handle_level_irq, + .flags = IRQ_LEVEL | IRQ_NOPROBE, +}; + +static struct or1k_pic_dev or1k_pic_edge = { + .chip = { + .name = "or1k-PIC-edge", + .irq_unmask = or1k_pic_unmask, + .irq_mask = or1k_pic_mask, + .irq_ack = or1k_pic_ack, + .irq_mask_ack = or1k_pic_mask_ack, + }, + .handle = handle_edge_irq, + .flags = IRQ_LEVEL | IRQ_NOPROBE, +}; + +static struct or1k_pic_dev or1k_pic_or1200 = { + .chip = { + .name = "or1200-PIC", + .irq_unmask = or1k_pic_unmask, + .irq_mask = or1k_pic_mask, + .irq_ack = or1k_pic_or1200_ack, + .irq_mask_ack = or1k_pic_or1200_mask_ack, + }, + .handle = handle_level_irq, + .flags = IRQ_LEVEL | IRQ_NOPROBE, +}; + +static struct irq_domain *root_domain; + +static inline int pic_get_irq(int first) +{ + int hwirq; + + hwirq = ffs(mfspr(SPR_PICSR) >> first); + if (!hwirq) + return NO_IRQ; + else + hwirq = hwirq + first - 1; + + return hwirq; +} + +static void or1k_pic_handle_irq(struct pt_regs *regs) +{ + int irq = -1; + + while ((irq = pic_get_irq(irq + 1)) != NO_IRQ) + generic_handle_domain_irq(root_domain, irq); +} + +static int or1k_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw) +{ + struct or1k_pic_dev *pic = d->host_data; + + irq_set_chip_and_handler(irq, &pic->chip, pic->handle); + irq_set_status_flags(irq, pic->flags); + + return 0; +} + +static const struct irq_domain_ops or1k_irq_domain_ops = { + .xlate = irq_domain_xlate_onecell, + .map = or1k_map, +}; + +/* + * This sets up the IRQ domain for the PIC built in to the OpenRISC + * 1000 CPU. This is the "root" domain as these are the interrupts + * that directly trigger an exception in the CPU. + */ +static int __init or1k_pic_init(struct device_node *node, + struct or1k_pic_dev *pic) +{ + /* Disable all interrupts until explicitly requested */ + mtspr(SPR_PICMR, (0UL)); + + root_domain = irq_domain_add_linear(node, 32, &or1k_irq_domain_ops, + pic); + + set_handle_irq(or1k_pic_handle_irq); + + return 0; +} + +static int __init or1k_pic_or1200_init(struct device_node *node, + struct device_node *parent) +{ + return or1k_pic_init(node, &or1k_pic_or1200); +} +IRQCHIP_DECLARE(or1k_pic_or1200, "opencores,or1200-pic", or1k_pic_or1200_init); +IRQCHIP_DECLARE(or1k_pic, "opencores,or1k-pic", or1k_pic_or1200_init); + +static int __init or1k_pic_level_init(struct device_node *node, + struct device_node *parent) +{ + return or1k_pic_init(node, &or1k_pic_level); +} +IRQCHIP_DECLARE(or1k_pic_level, "opencores,or1k-pic-level", + or1k_pic_level_init); + +static int __init or1k_pic_edge_init(struct device_node *node, + struct device_node *parent) +{ + return or1k_pic_init(node, &or1k_pic_edge); +} +IRQCHIP_DECLARE(or1k_pic_edge, "opencores,or1k-pic-edge", or1k_pic_edge_init); |