diff options
Diffstat (limited to 'drivers/irqchip/irq-aspeed-scu-ic.c')
| -rw-r--r-- | drivers/irqchip/irq-aspeed-scu-ic.c | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-aspeed-scu-ic.c b/drivers/irqchip/irq-aspeed-scu-ic.c new file mode 100644 index 000000000..279e92cf0 --- /dev/null +++ b/drivers/irqchip/irq-aspeed-scu-ic.c @@ -0,0 +1,237 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Aspeed AST24XX, AST25XX, and AST26XX SCU Interrupt Controller + * Copyright 2019 IBM Corporation + * + * Eddie James <eajames@linux.ibm.com> + */ + +#include <linux/bitops.h> +#include <linux/irq.h> +#include <linux/irqchip.h> +#include <linux/irqchip/chained_irq.h> +#include <linux/irqdomain.h> +#include <linux/mfd/syscon.h> +#include <linux/of_irq.h> +#include <linux/regmap.h> + +#define ASPEED_SCU_IC_REG 0x018 +#define ASPEED_SCU_IC_SHIFT 0 +#define ASPEED_SCU_IC_ENABLE GENMASK(6, ASPEED_SCU_IC_SHIFT) +#define ASPEED_SCU_IC_NUM_IRQS 7 +#define ASPEED_SCU_IC_STATUS_SHIFT 16 + +#define ASPEED_AST2600_SCU_IC0_REG 0x560 +#define ASPEED_AST2600_SCU_IC0_SHIFT 0 +#define ASPEED_AST2600_SCU_IC0_ENABLE \ + GENMASK(5, ASPEED_AST2600_SCU_IC0_SHIFT) +#define ASPEED_AST2600_SCU_IC0_NUM_IRQS 6 + +#define ASPEED_AST2600_SCU_IC1_REG 0x570 +#define ASPEED_AST2600_SCU_IC1_SHIFT 4 +#define ASPEED_AST2600_SCU_IC1_ENABLE \ + GENMASK(5, ASPEED_AST2600_SCU_IC1_SHIFT) +#define ASPEED_AST2600_SCU_IC1_NUM_IRQS 2 + +struct aspeed_scu_ic { + unsigned long irq_enable; + unsigned long irq_shift; + unsigned int num_irqs; + unsigned int reg; + struct regmap *scu; + struct irq_domain *irq_domain; +}; + +static void aspeed_scu_ic_irq_handler(struct irq_desc *desc) +{ + unsigned int sts; + unsigned long bit; + unsigned long enabled; + unsigned long max; + unsigned long status; + struct aspeed_scu_ic *scu_ic = irq_desc_get_handler_data(desc); + struct irq_chip *chip = irq_desc_get_chip(desc); + unsigned int mask = scu_ic->irq_enable << ASPEED_SCU_IC_STATUS_SHIFT; + + chained_irq_enter(chip, desc); + + /* + * The SCU IC has just one register to control its operation and read + * status. The interrupt enable bits occupy the lower 16 bits of the + * register, while the interrupt status bits occupy the upper 16 bits. + * The status bit for a given interrupt is always 16 bits shifted from + * the enable bit for the same interrupt. + * Therefore, perform the IRQ operations in the enable bit space by + * shifting the status down to get the mapping and then back up to + * clear the bit. + */ + regmap_read(scu_ic->scu, scu_ic->reg, &sts); + enabled = sts & scu_ic->irq_enable; + status = (sts >> ASPEED_SCU_IC_STATUS_SHIFT) & enabled; + + bit = scu_ic->irq_shift; + max = scu_ic->num_irqs + bit; + + for_each_set_bit_from(bit, &status, max) { + generic_handle_domain_irq(scu_ic->irq_domain, + bit - scu_ic->irq_shift); + + regmap_write_bits(scu_ic->scu, scu_ic->reg, mask, + BIT(bit + ASPEED_SCU_IC_STATUS_SHIFT)); + } + + chained_irq_exit(chip, desc); +} + +static void aspeed_scu_ic_irq_mask(struct irq_data *data) +{ + struct aspeed_scu_ic *scu_ic = irq_data_get_irq_chip_data(data); + unsigned int mask = BIT(data->hwirq + scu_ic->irq_shift) | + (scu_ic->irq_enable << ASPEED_SCU_IC_STATUS_SHIFT); + + /* + * Status bits are cleared by writing 1. In order to prevent the mask + * operation from clearing the status bits, they should be under the + * mask and written with 0. + */ + regmap_update_bits(scu_ic->scu, scu_ic->reg, mask, 0); +} + +static void aspeed_scu_ic_irq_unmask(struct irq_data *data) +{ + struct aspeed_scu_ic *scu_ic = irq_data_get_irq_chip_data(data); + unsigned int bit = BIT(data->hwirq + scu_ic->irq_shift); + unsigned int mask = bit | + (scu_ic->irq_enable << ASPEED_SCU_IC_STATUS_SHIFT); + + /* + * Status bits are cleared by writing 1. In order to prevent the unmask + * operation from clearing the status bits, they should be under the + * mask and written with 0. + */ + regmap_update_bits(scu_ic->scu, scu_ic->reg, mask, bit); +} + +static int aspeed_scu_ic_irq_set_affinity(struct irq_data *data, + const struct cpumask *dest, + bool force) +{ + return -EINVAL; +} + +static struct irq_chip aspeed_scu_ic_chip = { + .name = "aspeed-scu-ic", + .irq_mask = aspeed_scu_ic_irq_mask, + .irq_unmask = aspeed_scu_ic_irq_unmask, + .irq_set_affinity = aspeed_scu_ic_irq_set_affinity, +}; + +static int aspeed_scu_ic_map(struct irq_domain *domain, unsigned int irq, + irq_hw_number_t hwirq) +{ + irq_set_chip_and_handler(irq, &aspeed_scu_ic_chip, handle_level_irq); + irq_set_chip_data(irq, domain->host_data); + + return 0; +} + +static const struct irq_domain_ops aspeed_scu_ic_domain_ops = { + .map = aspeed_scu_ic_map, +}; + +static int aspeed_scu_ic_of_init_common(struct aspeed_scu_ic *scu_ic, + struct device_node *node) +{ + int irq; + int rc = 0; + + if (!node->parent) { + rc = -ENODEV; + goto err; + } + + scu_ic->scu = syscon_node_to_regmap(node->parent); + if (IS_ERR(scu_ic->scu)) { + rc = PTR_ERR(scu_ic->scu); + goto err; + } + + irq = irq_of_parse_and_map(node, 0); + if (!irq) { + rc = -EINVAL; + goto err; + } + + scu_ic->irq_domain = irq_domain_add_linear(node, scu_ic->num_irqs, + &aspeed_scu_ic_domain_ops, + scu_ic); + if (!scu_ic->irq_domain) { + rc = -ENOMEM; + goto err; + } + + irq_set_chained_handler_and_data(irq, aspeed_scu_ic_irq_handler, + scu_ic); + + return 0; + +err: + kfree(scu_ic); + + return rc; +} + +static int __init aspeed_scu_ic_of_init(struct device_node *node, + struct device_node *parent) +{ + struct aspeed_scu_ic *scu_ic = kzalloc(sizeof(*scu_ic), GFP_KERNEL); + + if (!scu_ic) + return -ENOMEM; + + scu_ic->irq_enable = ASPEED_SCU_IC_ENABLE; + scu_ic->irq_shift = ASPEED_SCU_IC_SHIFT; + scu_ic->num_irqs = ASPEED_SCU_IC_NUM_IRQS; + scu_ic->reg = ASPEED_SCU_IC_REG; + + return aspeed_scu_ic_of_init_common(scu_ic, node); +} + +static int __init aspeed_ast2600_scu_ic0_of_init(struct device_node *node, + struct device_node *parent) +{ + struct aspeed_scu_ic *scu_ic = kzalloc(sizeof(*scu_ic), GFP_KERNEL); + + if (!scu_ic) + return -ENOMEM; + + scu_ic->irq_enable = ASPEED_AST2600_SCU_IC0_ENABLE; + scu_ic->irq_shift = ASPEED_AST2600_SCU_IC0_SHIFT; + scu_ic->num_irqs = ASPEED_AST2600_SCU_IC0_NUM_IRQS; + scu_ic->reg = ASPEED_AST2600_SCU_IC0_REG; + + return aspeed_scu_ic_of_init_common(scu_ic, node); +} + +static int __init aspeed_ast2600_scu_ic1_of_init(struct device_node *node, + struct device_node *parent) +{ + struct aspeed_scu_ic *scu_ic = kzalloc(sizeof(*scu_ic), GFP_KERNEL); + + if (!scu_ic) + return -ENOMEM; + + scu_ic->irq_enable = ASPEED_AST2600_SCU_IC1_ENABLE; + scu_ic->irq_shift = ASPEED_AST2600_SCU_IC1_SHIFT; + scu_ic->num_irqs = ASPEED_AST2600_SCU_IC1_NUM_IRQS; + scu_ic->reg = ASPEED_AST2600_SCU_IC1_REG; + + return aspeed_scu_ic_of_init_common(scu_ic, node); +} + +IRQCHIP_DECLARE(ast2400_scu_ic, "aspeed,ast2400-scu-ic", aspeed_scu_ic_of_init); +IRQCHIP_DECLARE(ast2500_scu_ic, "aspeed,ast2500-scu-ic", aspeed_scu_ic_of_init); +IRQCHIP_DECLARE(ast2600_scu_ic0, "aspeed,ast2600-scu-ic0", + aspeed_ast2600_scu_ic0_of_init); +IRQCHIP_DECLARE(ast2600_scu_ic1, "aspeed,ast2600-scu-ic1", + aspeed_ast2600_scu_ic1_of_init); |