diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/irqchip/qcom-pdc.c | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/drivers/irqchip/qcom-pdc.c b/drivers/irqchip/qcom-pdc.c new file mode 100644 index 000000000..d96916cf6 --- /dev/null +++ b/drivers/irqchip/qcom-pdc.c @@ -0,0 +1,341 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2017-2019, The Linux Foundation. All rights reserved. + */ + +#include <linux/err.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/irqchip.h> +#include <linux/irqdomain.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/of_irq.h> +#include <linux/soc/qcom/irq.h> +#include <linux/spinlock.h> +#include <linux/slab.h> +#include <linux/types.h> + +#define PDC_MAX_GPIO_IRQS 256 + +#define IRQ_ENABLE_BANK 0x10 +#define IRQ_i_CFG 0x110 + +struct pdc_pin_region { + u32 pin_base; + u32 parent_base; + u32 cnt; +}; + +#define pin_to_hwirq(r, p) ((r)->parent_base + (p) - (r)->pin_base) + +static DEFINE_RAW_SPINLOCK(pdc_lock); +static void __iomem *pdc_base; +static struct pdc_pin_region *pdc_region; +static int pdc_region_cnt; + +static void pdc_reg_write(int reg, u32 i, u32 val) +{ + writel_relaxed(val, pdc_base + reg + i * sizeof(u32)); +} + +static u32 pdc_reg_read(int reg, u32 i) +{ + return readl_relaxed(pdc_base + reg + i * sizeof(u32)); +} + +static void pdc_enable_intr(struct irq_data *d, bool on) +{ + int pin_out = d->hwirq; + unsigned long enable; + unsigned long flags; + u32 index, mask; + + index = pin_out / 32; + mask = pin_out % 32; + + raw_spin_lock_irqsave(&pdc_lock, flags); + enable = pdc_reg_read(IRQ_ENABLE_BANK, index); + __assign_bit(mask, &enable, on); + pdc_reg_write(IRQ_ENABLE_BANK, index, enable); + raw_spin_unlock_irqrestore(&pdc_lock, flags); +} + +static void qcom_pdc_gic_disable(struct irq_data *d) +{ + pdc_enable_intr(d, false); + irq_chip_disable_parent(d); +} + +static void qcom_pdc_gic_enable(struct irq_data *d) +{ + pdc_enable_intr(d, true); + irq_chip_enable_parent(d); +} + +/* + * GIC does not handle falling edge or active low. To allow falling edge and + * active low interrupts to be handled at GIC, PDC has an inverter that inverts + * falling edge into a rising edge and active low into an active high. + * For the inverter to work, the polarity bit in the IRQ_CONFIG register has to + * set as per the table below. + * Level sensitive active low LOW + * Rising edge sensitive NOT USED + * Falling edge sensitive LOW + * Dual Edge sensitive NOT USED + * Level sensitive active High HIGH + * Falling Edge sensitive NOT USED + * Rising edge sensitive HIGH + * Dual Edge sensitive HIGH + */ +enum pdc_irq_config_bits { + PDC_LEVEL_LOW = 0b000, + PDC_EDGE_FALLING = 0b010, + PDC_LEVEL_HIGH = 0b100, + PDC_EDGE_RISING = 0b110, + PDC_EDGE_DUAL = 0b111, +}; + +/** + * qcom_pdc_gic_set_type: Configure PDC for the interrupt + * + * @d: the interrupt data + * @type: the interrupt type + * + * If @type is edge triggered, forward that as Rising edge as PDC + * takes care of converting falling edge to rising edge signal + * If @type is level, then forward that as level high as PDC + * takes care of converting falling edge to rising edge signal + */ +static int qcom_pdc_gic_set_type(struct irq_data *d, unsigned int type) +{ + enum pdc_irq_config_bits pdc_type; + enum pdc_irq_config_bits old_pdc_type; + int ret; + + switch (type) { + case IRQ_TYPE_EDGE_RISING: + pdc_type = PDC_EDGE_RISING; + break; + case IRQ_TYPE_EDGE_FALLING: + pdc_type = PDC_EDGE_FALLING; + type = IRQ_TYPE_EDGE_RISING; + break; + case IRQ_TYPE_EDGE_BOTH: + pdc_type = PDC_EDGE_DUAL; + type = IRQ_TYPE_EDGE_RISING; + break; + case IRQ_TYPE_LEVEL_HIGH: + pdc_type = PDC_LEVEL_HIGH; + break; + case IRQ_TYPE_LEVEL_LOW: + pdc_type = PDC_LEVEL_LOW; + type = IRQ_TYPE_LEVEL_HIGH; + break; + default: + WARN_ON(1); + return -EINVAL; + } + + old_pdc_type = pdc_reg_read(IRQ_i_CFG, d->hwirq); + pdc_reg_write(IRQ_i_CFG, d->hwirq, pdc_type); + + ret = irq_chip_set_type_parent(d, type); + if (ret) + return ret; + + /* + * When we change types the PDC can give a phantom interrupt. + * Clear it. Specifically the phantom shows up when reconfiguring + * polarity of interrupt without changing the state of the signal + * but let's be consistent and clear it always. + * + * Doing this works because we have IRQCHIP_SET_TYPE_MASKED so the + * interrupt will be cleared before the rest of the system sees it. + */ + if (old_pdc_type != pdc_type) + irq_chip_set_parent_state(d, IRQCHIP_STATE_PENDING, false); + + return 0; +} + +static struct irq_chip qcom_pdc_gic_chip = { + .name = "PDC", + .irq_eoi = irq_chip_eoi_parent, + .irq_mask = irq_chip_mask_parent, + .irq_unmask = irq_chip_unmask_parent, + .irq_disable = qcom_pdc_gic_disable, + .irq_enable = qcom_pdc_gic_enable, + .irq_get_irqchip_state = irq_chip_get_parent_state, + .irq_set_irqchip_state = irq_chip_set_parent_state, + .irq_retrigger = irq_chip_retrigger_hierarchy, + .irq_set_type = qcom_pdc_gic_set_type, + .flags = IRQCHIP_MASK_ON_SUSPEND | + IRQCHIP_SET_TYPE_MASKED | + IRQCHIP_SKIP_SET_WAKE | + IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND, + .irq_set_vcpu_affinity = irq_chip_set_vcpu_affinity_parent, + .irq_set_affinity = irq_chip_set_affinity_parent, +}; + +static struct pdc_pin_region *get_pin_region(int pin) +{ + int i; + + for (i = 0; i < pdc_region_cnt; i++) { + if (pin >= pdc_region[i].pin_base && + pin < pdc_region[i].pin_base + pdc_region[i].cnt) + return &pdc_region[i]; + } + + return NULL; +} + +static int qcom_pdc_alloc(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs, void *data) +{ + struct irq_fwspec *fwspec = data; + struct irq_fwspec parent_fwspec; + struct pdc_pin_region *region; + irq_hw_number_t hwirq; + unsigned int type; + int ret; + + ret = irq_domain_translate_twocell(domain, fwspec, &hwirq, &type); + if (ret) + return ret; + + if (hwirq == GPIO_NO_WAKE_IRQ) + return irq_domain_disconnect_hierarchy(domain, virq); + + ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq, + &qcom_pdc_gic_chip, NULL); + if (ret) + return ret; + + region = get_pin_region(hwirq); + if (!region) + return irq_domain_disconnect_hierarchy(domain->parent, virq); + + if (type & IRQ_TYPE_EDGE_BOTH) + type = IRQ_TYPE_EDGE_RISING; + + if (type & IRQ_TYPE_LEVEL_MASK) + type = IRQ_TYPE_LEVEL_HIGH; + + parent_fwspec.fwnode = domain->parent->fwnode; + parent_fwspec.param_count = 3; + parent_fwspec.param[0] = 0; + parent_fwspec.param[1] = pin_to_hwirq(region, hwirq); + parent_fwspec.param[2] = type; + + return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, + &parent_fwspec); +} + +static const struct irq_domain_ops qcom_pdc_ops = { + .translate = irq_domain_translate_twocell, + .alloc = qcom_pdc_alloc, + .free = irq_domain_free_irqs_common, +}; + +static int pdc_setup_pin_mapping(struct device_node *np) +{ + int ret, n, i; + u32 irq_index, reg_index, val; + + n = of_property_count_elems_of_size(np, "qcom,pdc-ranges", sizeof(u32)); + if (n <= 0 || n % 3) + return -EINVAL; + + pdc_region_cnt = n / 3; + pdc_region = kcalloc(pdc_region_cnt, sizeof(*pdc_region), GFP_KERNEL); + if (!pdc_region) { + pdc_region_cnt = 0; + return -ENOMEM; + } + + for (n = 0; n < pdc_region_cnt; n++) { + ret = of_property_read_u32_index(np, "qcom,pdc-ranges", + n * 3 + 0, + &pdc_region[n].pin_base); + if (ret) + return ret; + ret = of_property_read_u32_index(np, "qcom,pdc-ranges", + n * 3 + 1, + &pdc_region[n].parent_base); + if (ret) + return ret; + ret = of_property_read_u32_index(np, "qcom,pdc-ranges", + n * 3 + 2, + &pdc_region[n].cnt); + if (ret) + return ret; + + for (i = 0; i < pdc_region[n].cnt; i++) { + reg_index = (i + pdc_region[n].pin_base) >> 5; + irq_index = (i + pdc_region[n].pin_base) & 0x1f; + val = pdc_reg_read(IRQ_ENABLE_BANK, reg_index); + val &= ~BIT(irq_index); + pdc_reg_write(IRQ_ENABLE_BANK, reg_index, val); + } + } + + return 0; +} + +static int qcom_pdc_init(struct device_node *node, struct device_node *parent) +{ + struct irq_domain *parent_domain, *pdc_domain; + int ret; + + pdc_base = of_iomap(node, 0); + if (!pdc_base) { + pr_err("%pOF: unable to map PDC registers\n", node); + return -ENXIO; + } + + parent_domain = irq_find_host(parent); + if (!parent_domain) { + pr_err("%pOF: unable to find PDC's parent domain\n", node); + ret = -ENXIO; + goto fail; + } + + ret = pdc_setup_pin_mapping(node); + if (ret) { + pr_err("%pOF: failed to init PDC pin-hwirq mapping\n", node); + goto fail; + } + + pdc_domain = irq_domain_create_hierarchy(parent_domain, + IRQ_DOMAIN_FLAG_QCOM_PDC_WAKEUP, + PDC_MAX_GPIO_IRQS, + of_fwnode_handle(node), + &qcom_pdc_ops, NULL); + if (!pdc_domain) { + pr_err("%pOF: PDC domain add failed\n", node); + ret = -ENOMEM; + goto fail; + } + + irq_domain_update_bus_token(pdc_domain, DOMAIN_BUS_WAKEUP); + + return 0; + +fail: + kfree(pdc_region); + iounmap(pdc_base); + return ret; +} + +IRQCHIP_PLATFORM_DRIVER_BEGIN(qcom_pdc) +IRQCHIP_MATCH("qcom,pdc", qcom_pdc_init) +IRQCHIP_PLATFORM_DRIVER_END(qcom_pdc) +MODULE_DESCRIPTION("Qualcomm Technologies, Inc. Power Domain Controller"); +MODULE_LICENSE("GPL v2"); |