| 1 | /* |
| 2 | * Texas Instruments Keystone IRQ controller IP driver |
| 3 | * |
| 4 | * Copyright (C) 2014 Texas Instruments, Inc. |
| 5 | * Author: Sajesh Kumar Saran <sajesh@ti.com> |
| 6 | * Grygorii Strashko <grygorii.strashko@ti.com> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU General Public License as |
| 10 | * published by the Free Software Foundation version 2. |
| 11 | * |
| 12 | * This program is distributed "as is" WITHOUT ANY WARRANTY of any |
| 13 | * kind, whether express or implied; without even the implied warranty |
| 14 | * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | */ |
| 17 | |
| 18 | #include <linux/irq.h> |
| 19 | #include <linux/bitops.h> |
| 20 | #include <linux/module.h> |
| 21 | #include <linux/moduleparam.h> |
| 22 | #include <linux/irqdomain.h> |
| 23 | #include <linux/irqchip.h> |
| 24 | #include <linux/irqchip/chained_irq.h> |
| 25 | #include <linux/of.h> |
| 26 | #include <linux/of_platform.h> |
| 27 | #include <linux/mfd/syscon.h> |
| 28 | #include <linux/regmap.h> |
| 29 | |
| 30 | /* The source ID bits start from 4 to 31 (total 28 bits)*/ |
| 31 | #define BIT_OFS 4 |
| 32 | #define KEYSTONE_N_IRQ (32 - BIT_OFS) |
| 33 | |
| 34 | struct keystone_irq_device { |
| 35 | struct device *dev; |
| 36 | struct irq_chip chip; |
| 37 | u32 mask; |
| 38 | int irq; |
| 39 | struct irq_domain *irqd; |
| 40 | struct regmap *devctrl_regs; |
| 41 | u32 devctrl_offset; |
| 42 | }; |
| 43 | |
| 44 | static inline u32 keystone_irq_readl(struct keystone_irq_device *kirq) |
| 45 | { |
| 46 | int ret; |
| 47 | u32 val = 0; |
| 48 | |
| 49 | ret = regmap_read(kirq->devctrl_regs, kirq->devctrl_offset, &val); |
| 50 | if (ret < 0) |
| 51 | dev_dbg(kirq->dev, "irq read failed ret(%d)\n", ret); |
| 52 | return val; |
| 53 | } |
| 54 | |
| 55 | static inline void |
| 56 | keystone_irq_writel(struct keystone_irq_device *kirq, u32 value) |
| 57 | { |
| 58 | int ret; |
| 59 | |
| 60 | ret = regmap_write(kirq->devctrl_regs, kirq->devctrl_offset, value); |
| 61 | if (ret < 0) |
| 62 | dev_dbg(kirq->dev, "irq write failed ret(%d)\n", ret); |
| 63 | } |
| 64 | |
| 65 | static void keystone_irq_setmask(struct irq_data *d) |
| 66 | { |
| 67 | struct keystone_irq_device *kirq = irq_data_get_irq_chip_data(d); |
| 68 | |
| 69 | kirq->mask |= BIT(d->hwirq); |
| 70 | dev_dbg(kirq->dev, "mask %lu [%x]\n", d->hwirq, kirq->mask); |
| 71 | } |
| 72 | |
| 73 | static void keystone_irq_unmask(struct irq_data *d) |
| 74 | { |
| 75 | struct keystone_irq_device *kirq = irq_data_get_irq_chip_data(d); |
| 76 | |
| 77 | kirq->mask &= ~BIT(d->hwirq); |
| 78 | dev_dbg(kirq->dev, "unmask %lu [%x]\n", d->hwirq, kirq->mask); |
| 79 | } |
| 80 | |
| 81 | static void keystone_irq_ack(struct irq_data *d) |
| 82 | { |
| 83 | /* nothing to do here */ |
| 84 | } |
| 85 | |
| 86 | static void keystone_irq_handler(struct irq_desc *desc) |
| 87 | { |
| 88 | unsigned int irq = irq_desc_get_irq(desc); |
| 89 | struct keystone_irq_device *kirq = irq_desc_get_handler_data(desc); |
| 90 | unsigned long pending; |
| 91 | int src, virq; |
| 92 | |
| 93 | dev_dbg(kirq->dev, "start irq %d\n", irq); |
| 94 | |
| 95 | chained_irq_enter(irq_desc_get_chip(desc), desc); |
| 96 | |
| 97 | pending = keystone_irq_readl(kirq); |
| 98 | keystone_irq_writel(kirq, pending); |
| 99 | |
| 100 | dev_dbg(kirq->dev, "pending 0x%lx, mask 0x%x\n", pending, kirq->mask); |
| 101 | |
| 102 | pending = (pending >> BIT_OFS) & ~kirq->mask; |
| 103 | |
| 104 | dev_dbg(kirq->dev, "pending after mask 0x%lx\n", pending); |
| 105 | |
| 106 | for (src = 0; src < KEYSTONE_N_IRQ; src++) { |
| 107 | if (BIT(src) & pending) { |
| 108 | virq = irq_find_mapping(kirq->irqd, src); |
| 109 | dev_dbg(kirq->dev, "dispatch bit %d, virq %d\n", |
| 110 | src, virq); |
| 111 | if (!virq) |
| 112 | dev_warn(kirq->dev, "sporious irq detected hwirq %d, virq %d\n", |
| 113 | src, virq); |
| 114 | generic_handle_irq(virq); |
| 115 | } |
| 116 | } |
| 117 | |
| 118 | chained_irq_exit(irq_desc_get_chip(desc), desc); |
| 119 | |
| 120 | dev_dbg(kirq->dev, "end irq %d\n", irq); |
| 121 | } |
| 122 | |
| 123 | static int keystone_irq_map(struct irq_domain *h, unsigned int virq, |
| 124 | irq_hw_number_t hw) |
| 125 | { |
| 126 | struct keystone_irq_device *kirq = h->host_data; |
| 127 | |
| 128 | irq_set_chip_data(virq, kirq); |
| 129 | irq_set_chip_and_handler(virq, &kirq->chip, handle_level_irq); |
| 130 | irq_set_probe(virq); |
| 131 | return 0; |
| 132 | } |
| 133 | |
| 134 | static const struct irq_domain_ops keystone_irq_ops = { |
| 135 | .map = keystone_irq_map, |
| 136 | .xlate = irq_domain_xlate_onecell, |
| 137 | }; |
| 138 | |
| 139 | static int keystone_irq_probe(struct platform_device *pdev) |
| 140 | { |
| 141 | struct device *dev = &pdev->dev; |
| 142 | struct device_node *np = dev->of_node; |
| 143 | struct keystone_irq_device *kirq; |
| 144 | int ret; |
| 145 | |
| 146 | if (np == NULL) |
| 147 | return -EINVAL; |
| 148 | |
| 149 | kirq = devm_kzalloc(dev, sizeof(*kirq), GFP_KERNEL); |
| 150 | if (!kirq) |
| 151 | return -ENOMEM; |
| 152 | |
| 153 | kirq->devctrl_regs = |
| 154 | syscon_regmap_lookup_by_phandle(np, "ti,syscon-dev"); |
| 155 | if (IS_ERR(kirq->devctrl_regs)) |
| 156 | return PTR_ERR(kirq->devctrl_regs); |
| 157 | |
| 158 | ret = of_property_read_u32_index(np, "ti,syscon-dev", 1, |
| 159 | &kirq->devctrl_offset); |
| 160 | if (ret) { |
| 161 | dev_err(dev, "couldn't read the devctrl_offset offset!\n"); |
| 162 | return ret; |
| 163 | } |
| 164 | |
| 165 | kirq->irq = platform_get_irq(pdev, 0); |
| 166 | if (kirq->irq < 0) { |
| 167 | dev_err(dev, "no irq resource %d\n", kirq->irq); |
| 168 | return kirq->irq; |
| 169 | } |
| 170 | |
| 171 | kirq->dev = dev; |
| 172 | kirq->mask = ~0x0; |
| 173 | kirq->chip.name = "keystone-irq"; |
| 174 | kirq->chip.irq_ack = keystone_irq_ack; |
| 175 | kirq->chip.irq_mask = keystone_irq_setmask; |
| 176 | kirq->chip.irq_unmask = keystone_irq_unmask; |
| 177 | |
| 178 | kirq->irqd = irq_domain_add_linear(np, KEYSTONE_N_IRQ, |
| 179 | &keystone_irq_ops, kirq); |
| 180 | if (!kirq->irqd) { |
| 181 | dev_err(dev, "IRQ domain registration failed\n"); |
| 182 | return -ENODEV; |
| 183 | } |
| 184 | |
| 185 | platform_set_drvdata(pdev, kirq); |
| 186 | |
| 187 | irq_set_chained_handler_and_data(kirq->irq, keystone_irq_handler, kirq); |
| 188 | |
| 189 | /* clear all source bits */ |
| 190 | keystone_irq_writel(kirq, ~0x0); |
| 191 | |
| 192 | dev_info(dev, "irqchip registered, nr_irqs %u\n", KEYSTONE_N_IRQ); |
| 193 | |
| 194 | return 0; |
| 195 | } |
| 196 | |
| 197 | static int keystone_irq_remove(struct platform_device *pdev) |
| 198 | { |
| 199 | struct keystone_irq_device *kirq = platform_get_drvdata(pdev); |
| 200 | int hwirq; |
| 201 | |
| 202 | for (hwirq = 0; hwirq < KEYSTONE_N_IRQ; hwirq++) |
| 203 | irq_dispose_mapping(irq_find_mapping(kirq->irqd, hwirq)); |
| 204 | |
| 205 | irq_domain_remove(kirq->irqd); |
| 206 | return 0; |
| 207 | } |
| 208 | |
| 209 | static const struct of_device_id keystone_irq_dt_ids[] = { |
| 210 | { .compatible = "ti,keystone-irq", }, |
| 211 | {}, |
| 212 | }; |
| 213 | MODULE_DEVICE_TABLE(of, keystone_irq_dt_ids); |
| 214 | |
| 215 | static struct platform_driver keystone_irq_device_driver = { |
| 216 | .probe = keystone_irq_probe, |
| 217 | .remove = keystone_irq_remove, |
| 218 | .driver = { |
| 219 | .name = "keystone_irq", |
| 220 | .of_match_table = of_match_ptr(keystone_irq_dt_ids), |
| 221 | } |
| 222 | }; |
| 223 | |
| 224 | module_platform_driver(keystone_irq_device_driver); |
| 225 | |
| 226 | MODULE_AUTHOR("Texas Instruments"); |
| 227 | MODULE_AUTHOR("Sajesh Kumar Saran"); |
| 228 | MODULE_AUTHOR("Grygorii Strashko"); |
| 229 | MODULE_DESCRIPTION("Keystone IRQ chip"); |
| 230 | MODULE_LICENSE("GPL v2"); |