1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
3 */
4
5 /*
6 * Driver for interrupt combiners in the Top-level Control and Status
7 * Registers (TCSR) hardware block in Qualcomm Technologies chips.
8 * An interrupt combiner in this block combines a set of interrupts by
9 * OR'ing the individual interrupt signals into a summary interrupt
10 * signal routed to a parent interrupt controller, and provides read-
11 * only, 32-bit registers to query the status of individual interrupts.
12 * The status bit for IRQ n is bit (n % 32) within register (n / 32)
13 * of the given combiner. Thus, each combiner can be described as a set
14 * of register offsets and the number of IRQs managed.
15 */
16
17 #define pr_fmt(fmt) "QCOM80B1:" fmt
18
19 #include <linux/acpi.h>
20 #include <linux/irqchip/chained_irq.h>
21 #include <linux/irqdomain.h>
22 #include <linux/platform_device.h>
23
24 #define REG_SIZE 32
25
26 struct combiner_reg {
27 void __iomem *addr;
28 unsigned long enabled;
29 };
30
31 struct combiner {
32 struct irq_domain *domain;
33 int parent_irq;
34 u32 nirqs;
35 u32 nregs;
36 struct combiner_reg regs[];
37 };
38
irq_nr(u32 reg,u32 bit)39 static inline int irq_nr(u32 reg, u32 bit)
40 {
41 return reg * REG_SIZE + bit;
42 }
43
44 /*
45 * Handler for the cascaded IRQ.
46 */
combiner_handle_irq(struct irq_desc * desc)47 static void combiner_handle_irq(struct irq_desc *desc)
48 {
49 struct combiner *combiner = irq_desc_get_handler_data(desc);
50 struct irq_chip *chip = irq_desc_get_chip(desc);
51 u32 reg;
52
53 chained_irq_enter(chip, desc);
54
55 for (reg = 0; reg < combiner->nregs; reg++) {
56 int hwirq;
57 u32 bit;
58 u32 status;
59
60 bit = readl_relaxed(combiner->regs[reg].addr);
61 status = bit & combiner->regs[reg].enabled;
62 if (bit && !status)
63 pr_warn_ratelimited("Unexpected IRQ on CPU%d: (%08x %08lx %p)\n",
64 smp_processor_id(), bit,
65 combiner->regs[reg].enabled,
66 combiner->regs[reg].addr);
67
68 while (status) {
69 bit = __ffs(status);
70 status &= ~(1 << bit);
71 hwirq = irq_nr(reg, bit);
72 generic_handle_domain_irq(combiner->domain, hwirq);
73 }
74 }
75
76 chained_irq_exit(chip, desc);
77 }
78
combiner_irq_chip_mask_irq(struct irq_data * data)79 static void combiner_irq_chip_mask_irq(struct irq_data *data)
80 {
81 struct combiner *combiner = irq_data_get_irq_chip_data(data);
82 struct combiner_reg *reg = combiner->regs + data->hwirq / REG_SIZE;
83
84 clear_bit(data->hwirq % REG_SIZE, ®->enabled);
85 }
86
combiner_irq_chip_unmask_irq(struct irq_data * data)87 static void combiner_irq_chip_unmask_irq(struct irq_data *data)
88 {
89 struct combiner *combiner = irq_data_get_irq_chip_data(data);
90 struct combiner_reg *reg = combiner->regs + data->hwirq / REG_SIZE;
91
92 set_bit(data->hwirq % REG_SIZE, ®->enabled);
93 }
94
95 static struct irq_chip irq_chip = {
96 .irq_mask = combiner_irq_chip_mask_irq,
97 .irq_unmask = combiner_irq_chip_unmask_irq,
98 .name = "qcom-irq-combiner"
99 };
100
combiner_irq_map(struct irq_domain * domain,unsigned int irq,irq_hw_number_t hwirq)101 static int combiner_irq_map(struct irq_domain *domain, unsigned int irq,
102 irq_hw_number_t hwirq)
103 {
104 irq_set_chip_and_handler(irq, &irq_chip, handle_level_irq);
105 irq_set_chip_data(irq, domain->host_data);
106 irq_set_noprobe(irq);
107 return 0;
108 }
109
combiner_irq_unmap(struct irq_domain * domain,unsigned int irq)110 static void combiner_irq_unmap(struct irq_domain *domain, unsigned int irq)
111 {
112 irq_domain_reset_irq_data(irq_get_irq_data(irq));
113 }
114
combiner_irq_translate(struct irq_domain * d,struct irq_fwspec * fws,unsigned long * hwirq,unsigned int * type)115 static int combiner_irq_translate(struct irq_domain *d, struct irq_fwspec *fws,
116 unsigned long *hwirq, unsigned int *type)
117 {
118 struct combiner *combiner = d->host_data;
119
120 if (is_acpi_node(fws->fwnode)) {
121 if (WARN_ON((fws->param_count != 2) ||
122 (fws->param[0] >= combiner->nirqs) ||
123 (fws->param[1] & IORESOURCE_IRQ_LOWEDGE) ||
124 (fws->param[1] & IORESOURCE_IRQ_HIGHEDGE)))
125 return -EINVAL;
126
127 *hwirq = fws->param[0];
128 *type = fws->param[1];
129 return 0;
130 }
131
132 return -EINVAL;
133 }
134
135 static const struct irq_domain_ops domain_ops = {
136 .map = combiner_irq_map,
137 .unmap = combiner_irq_unmap,
138 .translate = combiner_irq_translate
139 };
140
count_registers_cb(struct acpi_resource * ares,void * context)141 static acpi_status count_registers_cb(struct acpi_resource *ares, void *context)
142 {
143 int *count = context;
144
145 if (ares->type == ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
146 ++(*count);
147 return AE_OK;
148 }
149
count_registers(struct platform_device * pdev)150 static int count_registers(struct platform_device *pdev)
151 {
152 acpi_handle ahandle = ACPI_HANDLE(&pdev->dev);
153 acpi_status status;
154 int count = 0;
155
156 if (!acpi_has_method(ahandle, METHOD_NAME__CRS))
157 return -EINVAL;
158
159 status = acpi_walk_resources(ahandle, METHOD_NAME__CRS,
160 count_registers_cb, &count);
161 if (ACPI_FAILURE(status))
162 return -EINVAL;
163 return count;
164 }
165
166 struct get_registers_context {
167 struct device *dev;
168 struct combiner *combiner;
169 int err;
170 };
171
get_registers_cb(struct acpi_resource * ares,void * context)172 static acpi_status get_registers_cb(struct acpi_resource *ares, void *context)
173 {
174 struct get_registers_context *ctx = context;
175 struct acpi_resource_generic_register *reg;
176 phys_addr_t paddr;
177 void __iomem *vaddr;
178
179 if (ares->type != ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
180 return AE_OK;
181
182 reg = &ares->data.generic_reg;
183 paddr = reg->address;
184 if ((reg->space_id != ACPI_SPACE_MEM) ||
185 (reg->bit_offset != 0) ||
186 (reg->bit_width > REG_SIZE)) {
187 dev_err(ctx->dev, "Bad register resource @%pa\n", &paddr);
188 ctx->err = -EINVAL;
189 return AE_ERROR;
190 }
191
192 vaddr = devm_ioremap(ctx->dev, reg->address, REG_SIZE);
193 if (!vaddr) {
194 dev_err(ctx->dev, "Can't map register @%pa\n", &paddr);
195 ctx->err = -ENOMEM;
196 return AE_ERROR;
197 }
198
199 ctx->combiner->regs[ctx->combiner->nregs].addr = vaddr;
200 ctx->combiner->nirqs += reg->bit_width;
201 ctx->combiner->nregs++;
202 return AE_OK;
203 }
204
get_registers(struct platform_device * pdev,struct combiner * comb)205 static int get_registers(struct platform_device *pdev, struct combiner *comb)
206 {
207 acpi_handle ahandle = ACPI_HANDLE(&pdev->dev);
208 acpi_status status;
209 struct get_registers_context ctx;
210
211 if (!acpi_has_method(ahandle, METHOD_NAME__CRS))
212 return -EINVAL;
213
214 ctx.dev = &pdev->dev;
215 ctx.combiner = comb;
216 ctx.err = 0;
217
218 status = acpi_walk_resources(ahandle, METHOD_NAME__CRS,
219 get_registers_cb, &ctx);
220 if (ACPI_FAILURE(status))
221 return ctx.err;
222 return 0;
223 }
224
combiner_probe(struct platform_device * pdev)225 static int __init combiner_probe(struct platform_device *pdev)
226 {
227 struct combiner *combiner;
228 int nregs;
229 int err;
230
231 nregs = count_registers(pdev);
232 if (nregs <= 0) {
233 dev_err(&pdev->dev, "Error reading register resources\n");
234 return -EINVAL;
235 }
236
237 combiner = devm_kzalloc(&pdev->dev, struct_size(combiner, regs, nregs),
238 GFP_KERNEL);
239 if (!combiner)
240 return -ENOMEM;
241
242 err = get_registers(pdev, combiner);
243 if (err < 0)
244 return err;
245
246 combiner->parent_irq = platform_get_irq(pdev, 0);
247 if (combiner->parent_irq <= 0)
248 return -EPROBE_DEFER;
249
250 combiner->domain = irq_domain_create_linear(pdev->dev.fwnode, combiner->nirqs,
251 &domain_ops, combiner);
252 if (!combiner->domain)
253 /* Errors printed by irq_domain_create_linear */
254 return -ENODEV;
255
256 irq_set_chained_handler_and_data(combiner->parent_irq,
257 combiner_handle_irq, combiner);
258
259 dev_info(&pdev->dev, "Initialized with [p=%d,n=%d,r=%p]\n",
260 combiner->parent_irq, combiner->nirqs, combiner->regs[0].addr);
261 return 0;
262 }
263
264 static const struct acpi_device_id qcom_irq_combiner_ids[] = {
265 { "QCOM80B1", },
266 { }
267 };
268
269 static struct platform_driver qcom_irq_combiner_probe = {
270 .driver = {
271 .name = "qcom-irq-combiner",
272 .acpi_match_table = ACPI_PTR(qcom_irq_combiner_ids),
273 },
274 .probe = combiner_probe,
275 };
276 builtin_platform_driver(qcom_irq_combiner_probe);
277