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| 1 | +// SPDX-License-Identifier: GPL-2.0-only |
| 2 | +/* |
| 3 | + * Microchip External Interrupt Controller driver |
| 4 | + * |
| 5 | + * Copyright (C) 2021 Microchip Technology Inc. and its subsidiaries |
| 6 | + * |
| 7 | + * Author: Claudiu Beznea <[email protected]> |
| 8 | + */ |
| 9 | +#include <linux/clk.h> |
| 10 | +#include <linux/delay.h> |
| 11 | +#include <linux/interrupt.h> |
| 12 | +#include <linux/irqchip.h> |
| 13 | +#include <linux/of_address.h> |
| 14 | +#include <linux/of_irq.h> |
| 15 | +#include <linux/syscore_ops.h> |
| 16 | + |
| 17 | +#include <dt-bindings/interrupt-controller/arm-gic.h> |
| 18 | + |
| 19 | +#define MCHP_EIC_GFCS (0x0) |
| 20 | +#define MCHP_EIC_SCFG(x) (0x4 + (x) * 0x4) |
| 21 | +#define MCHP_EIC_SCFG_EN BIT(16) |
| 22 | +#define MCHP_EIC_SCFG_LVL BIT(9) |
| 23 | +#define MCHP_EIC_SCFG_POL BIT(8) |
| 24 | + |
| 25 | +#define MCHP_EIC_NIRQ (2) |
| 26 | + |
| 27 | +/* |
| 28 | + * struct mchp_eic - EIC private data structure |
| 29 | + * @base: base address |
| 30 | + * @clk: peripheral clock |
| 31 | + * @domain: irq domain |
| 32 | + * @irqs: irqs b/w eic and gic |
| 33 | + * @scfg: backup for scfg registers (necessary for backup and self-refresh mode) |
| 34 | + * @wakeup_source: wakeup source mask |
| 35 | + */ |
| 36 | +struct mchp_eic { |
| 37 | + void __iomem *base; |
| 38 | + struct clk *clk; |
| 39 | + struct irq_domain *domain; |
| 40 | + u32 irqs[MCHP_EIC_NIRQ]; |
| 41 | + u32 scfg[MCHP_EIC_NIRQ]; |
| 42 | + u32 wakeup_source; |
| 43 | +}; |
| 44 | + |
| 45 | +static struct mchp_eic *eic; |
| 46 | + |
| 47 | +static void mchp_eic_irq_mask(struct irq_data *d) |
| 48 | +{ |
| 49 | + unsigned int tmp; |
| 50 | + |
| 51 | + tmp = readl_relaxed(eic->base + MCHP_EIC_SCFG(d->hwirq)); |
| 52 | + tmp &= ~MCHP_EIC_SCFG_EN; |
| 53 | + writel_relaxed(tmp, eic->base + MCHP_EIC_SCFG(d->hwirq)); |
| 54 | + |
| 55 | + irq_chip_mask_parent(d); |
| 56 | +} |
| 57 | + |
| 58 | +static void mchp_eic_irq_unmask(struct irq_data *d) |
| 59 | +{ |
| 60 | + unsigned int tmp; |
| 61 | + |
| 62 | + tmp = readl_relaxed(eic->base + MCHP_EIC_SCFG(d->hwirq)); |
| 63 | + tmp |= MCHP_EIC_SCFG_EN; |
| 64 | + writel_relaxed(tmp, eic->base + MCHP_EIC_SCFG(d->hwirq)); |
| 65 | + |
| 66 | + irq_chip_unmask_parent(d); |
| 67 | +} |
| 68 | + |
| 69 | +static int mchp_eic_irq_set_type(struct irq_data *d, unsigned int type) |
| 70 | +{ |
| 71 | + unsigned int parent_irq_type; |
| 72 | + unsigned int tmp; |
| 73 | + |
| 74 | + tmp = readl_relaxed(eic->base + MCHP_EIC_SCFG(d->hwirq)); |
| 75 | + tmp &= ~(MCHP_EIC_SCFG_POL | MCHP_EIC_SCFG_LVL); |
| 76 | + switch (type) { |
| 77 | + case IRQ_TYPE_LEVEL_HIGH: |
| 78 | + tmp |= MCHP_EIC_SCFG_POL | MCHP_EIC_SCFG_LVL; |
| 79 | + parent_irq_type = IRQ_TYPE_LEVEL_HIGH; |
| 80 | + break; |
| 81 | + case IRQ_TYPE_LEVEL_LOW: |
| 82 | + tmp |= MCHP_EIC_SCFG_LVL; |
| 83 | + parent_irq_type = IRQ_TYPE_LEVEL_HIGH; |
| 84 | + break; |
| 85 | + case IRQ_TYPE_EDGE_RISING: |
| 86 | + parent_irq_type = IRQ_TYPE_EDGE_RISING; |
| 87 | + break; |
| 88 | + case IRQ_TYPE_EDGE_FALLING: |
| 89 | + tmp |= MCHP_EIC_SCFG_POL; |
| 90 | + parent_irq_type = IRQ_TYPE_EDGE_RISING; |
| 91 | + break; |
| 92 | + default: |
| 93 | + return -EINVAL; |
| 94 | + } |
| 95 | + |
| 96 | + writel_relaxed(tmp, eic->base + MCHP_EIC_SCFG(d->hwirq)); |
| 97 | + |
| 98 | + return irq_chip_set_type_parent(d, parent_irq_type); |
| 99 | +} |
| 100 | + |
| 101 | +static int mchp_eic_irq_set_wake(struct irq_data *d, unsigned int on) |
| 102 | +{ |
| 103 | + irq_set_irq_wake(eic->irqs[d->hwirq], on); |
| 104 | + if (on) |
| 105 | + eic->wakeup_source |= BIT(d->hwirq); |
| 106 | + else |
| 107 | + eic->wakeup_source &= ~BIT(d->hwirq); |
| 108 | + |
| 109 | + return 0; |
| 110 | +} |
| 111 | + |
| 112 | +static int mchp_eic_irq_suspend(void) |
| 113 | +{ |
| 114 | + unsigned int hwirq; |
| 115 | + |
| 116 | + for (hwirq = 0; hwirq < MCHP_EIC_NIRQ; hwirq++) |
| 117 | + eic->scfg[hwirq] = readl_relaxed(eic->base + |
| 118 | + MCHP_EIC_SCFG(hwirq)); |
| 119 | + |
| 120 | + if (!eic->wakeup_source) |
| 121 | + clk_disable_unprepare(eic->clk); |
| 122 | + |
| 123 | + return 0; |
| 124 | +} |
| 125 | + |
| 126 | +static void mchp_eic_irq_resume(void) |
| 127 | +{ |
| 128 | + unsigned int hwirq; |
| 129 | + |
| 130 | + if (!eic->wakeup_source) |
| 131 | + clk_prepare_enable(eic->clk); |
| 132 | + |
| 133 | + for (hwirq = 0; hwirq < MCHP_EIC_NIRQ; hwirq++) |
| 134 | + writel_relaxed(eic->scfg[hwirq], eic->base + |
| 135 | + MCHP_EIC_SCFG(hwirq)); |
| 136 | +} |
| 137 | + |
| 138 | +static struct syscore_ops mchp_eic_syscore_ops = { |
| 139 | + .suspend = mchp_eic_irq_suspend, |
| 140 | + .resume = mchp_eic_irq_resume, |
| 141 | +}; |
| 142 | + |
| 143 | +static struct irq_chip mchp_eic_chip = { |
| 144 | + .name = "eic", |
| 145 | + .flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_SET_TYPE_MASKED, |
| 146 | + .irq_mask = mchp_eic_irq_mask, |
| 147 | + .irq_unmask = mchp_eic_irq_unmask, |
| 148 | + .irq_set_type = mchp_eic_irq_set_type, |
| 149 | + .irq_ack = irq_chip_ack_parent, |
| 150 | + .irq_eoi = irq_chip_eoi_parent, |
| 151 | + .irq_retrigger = irq_chip_retrigger_hierarchy, |
| 152 | + .irq_set_wake = mchp_eic_irq_set_wake, |
| 153 | +}; |
| 154 | + |
| 155 | +static int mchp_eic_domain_alloc(struct irq_domain *domain, unsigned int virq, |
| 156 | + unsigned int nr_irqs, void *data) |
| 157 | +{ |
| 158 | + struct irq_fwspec *fwspec = data; |
| 159 | + struct irq_fwspec parent_fwspec; |
| 160 | + irq_hw_number_t hwirq; |
| 161 | + unsigned int type; |
| 162 | + int ret; |
| 163 | + |
| 164 | + if (WARN_ON(nr_irqs != 1)) |
| 165 | + return -EINVAL; |
| 166 | + |
| 167 | + ret = irq_domain_translate_twocell(domain, fwspec, &hwirq, &type); |
| 168 | + if (ret || hwirq >= MCHP_EIC_NIRQ) |
| 169 | + return ret; |
| 170 | + |
| 171 | + switch (type) { |
| 172 | + case IRQ_TYPE_EDGE_RISING: |
| 173 | + case IRQ_TYPE_LEVEL_HIGH: |
| 174 | + break; |
| 175 | + case IRQ_TYPE_EDGE_FALLING: |
| 176 | + type = IRQ_TYPE_EDGE_RISING; |
| 177 | + break; |
| 178 | + case IRQ_TYPE_LEVEL_LOW: |
| 179 | + type = IRQ_TYPE_LEVEL_HIGH; |
| 180 | + break; |
| 181 | + default: |
| 182 | + return -EINVAL; |
| 183 | + } |
| 184 | + |
| 185 | + irq_domain_set_hwirq_and_chip(domain, virq, hwirq, &mchp_eic_chip, eic); |
| 186 | + |
| 187 | + parent_fwspec.fwnode = domain->parent->fwnode; |
| 188 | + parent_fwspec.param_count = 3; |
| 189 | + parent_fwspec.param[0] = GIC_SPI; |
| 190 | + parent_fwspec.param[1] = eic->irqs[hwirq]; |
| 191 | + parent_fwspec.param[2] = type; |
| 192 | + |
| 193 | + return irq_domain_alloc_irqs_parent(domain, virq, 1, &parent_fwspec); |
| 194 | +} |
| 195 | + |
| 196 | +static const struct irq_domain_ops mchp_eic_domain_ops = { |
| 197 | + .translate = irq_domain_translate_twocell, |
| 198 | + .alloc = mchp_eic_domain_alloc, |
| 199 | + .free = irq_domain_free_irqs_common, |
| 200 | +}; |
| 201 | + |
| 202 | +static int mchp_eic_init(struct device_node *node, struct device_node *parent) |
| 203 | +{ |
| 204 | + struct irq_domain *parent_domain = NULL; |
| 205 | + int ret, i; |
| 206 | + |
| 207 | + eic = kzalloc(sizeof(*eic), GFP_KERNEL); |
| 208 | + if (!eic) |
| 209 | + return -ENOMEM; |
| 210 | + |
| 211 | + eic->base = of_iomap(node, 0); |
| 212 | + if (!eic->base) { |
| 213 | + ret = -ENOMEM; |
| 214 | + goto free; |
| 215 | + } |
| 216 | + |
| 217 | + parent_domain = irq_find_host(parent); |
| 218 | + if (!parent_domain) { |
| 219 | + ret = -ENODEV; |
| 220 | + goto unmap; |
| 221 | + } |
| 222 | + |
| 223 | + eic->clk = of_clk_get_by_name(node, "pclk"); |
| 224 | + if (IS_ERR(eic->clk)) { |
| 225 | + ret = PTR_ERR(eic->clk); |
| 226 | + goto unmap; |
| 227 | + } |
| 228 | + |
| 229 | + ret = clk_prepare_enable(eic->clk); |
| 230 | + if (ret) |
| 231 | + goto unmap; |
| 232 | + |
| 233 | + for (i = 0; i < MCHP_EIC_NIRQ; i++) { |
| 234 | + struct of_phandle_args irq; |
| 235 | + |
| 236 | + /* Disable it, if any. */ |
| 237 | + writel_relaxed(0UL, eic->base + MCHP_EIC_SCFG(i)); |
| 238 | + |
| 239 | + ret = of_irq_parse_one(node, i, &irq); |
| 240 | + if (ret) |
| 241 | + goto clk_unprepare; |
| 242 | + |
| 243 | + if (WARN_ON(irq.args_count != 3)) { |
| 244 | + ret = -EINVAL; |
| 245 | + goto clk_unprepare; |
| 246 | + } |
| 247 | + |
| 248 | + eic->irqs[i] = irq.args[1]; |
| 249 | + } |
| 250 | + |
| 251 | + eic->domain = irq_domain_add_hierarchy(parent_domain, 0, MCHP_EIC_NIRQ, |
| 252 | + node, &mchp_eic_domain_ops, eic); |
| 253 | + if (!eic->domain) { |
| 254 | + pr_err("%pOF: Failed to add domain\n", node); |
| 255 | + ret = -ENODEV; |
| 256 | + goto clk_unprepare; |
| 257 | + } |
| 258 | + |
| 259 | + register_syscore_ops(&mchp_eic_syscore_ops); |
| 260 | + |
| 261 | + pr_info("%pOF: EIC registered, nr_irqs %u\n", node, MCHP_EIC_NIRQ); |
| 262 | + |
| 263 | + return 0; |
| 264 | + |
| 265 | +clk_unprepare: |
| 266 | + clk_disable_unprepare(eic->clk); |
| 267 | +unmap: |
| 268 | + iounmap(eic->base); |
| 269 | +free: |
| 270 | + kfree(eic); |
| 271 | + return ret; |
| 272 | +} |
| 273 | + |
| 274 | +IRQCHIP_PLATFORM_DRIVER_BEGIN(mchp_eic) |
| 275 | +IRQCHIP_MATCH("microchip,sama7g5-eic", mchp_eic_init) |
| 276 | +IRQCHIP_PLATFORM_DRIVER_END(mchp_eic) |
| 277 | + |
| 278 | +MODULE_DESCRIPTION("Microchip External Interrupt Controller"); |
| 279 | +MODULE_LICENSE("GPL v2"); |
| 280 | +MODULE_AUTHOR( "Claudiu Beznea <[email protected]>"); |
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