1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * SG2042 MSI Controller 4 * 5 * Copyright (C) 2024 Sophgo Technology Inc. 6 * Copyright (C) 2024 Chen Wang <unicorn_wang@outlook.com> 7 */ 8 9 #include <linux/cleanup.h> 10 #include <linux/io.h> 11 #include <linux/irq.h> 12 #include <linux/irqdomain.h> 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <linux/msi.h> 16 #include <linux/platform_device.h> 17 #include <linux/property.h> 18 #include <linux/slab.h> 19 20 #include "irq-msi-lib.h" 21 22 #define SG2042_MAX_MSI_VECTOR 32 23 24 struct sg2042_msi_chipdata { 25 void __iomem *reg_clr; // clear reg, see TRM, 10.1.33, GP_INTR0_CLR 26 27 phys_addr_t doorbell_addr; // see TRM, 10.1.32, GP_INTR0_SET 28 29 u32 irq_first; // The vector number that MSIs starts 30 u32 num_irqs; // The number of vectors for MSIs 31 32 DECLARE_BITMAP(msi_map, SG2042_MAX_MSI_VECTOR); 33 struct mutex msi_map_lock; // lock for msi_map 34 }; 35 36 static int sg2042_msi_allocate_hwirq(struct sg2042_msi_chipdata *data, int num_req) 37 { 38 int first; 39 40 guard(mutex)(&data->msi_map_lock); 41 first = bitmap_find_free_region(data->msi_map, data->num_irqs, 42 get_count_order(num_req)); 43 return first >= 0 ? first : -ENOSPC; 44 } 45 46 static void sg2042_msi_free_hwirq(struct sg2042_msi_chipdata *data, int hwirq, int num_req) 47 { 48 guard(mutex)(&data->msi_map_lock); 49 bitmap_release_region(data->msi_map, hwirq, get_count_order(num_req)); 50 } 51 52 static void sg2042_msi_irq_ack(struct irq_data *d) 53 { 54 struct sg2042_msi_chipdata *data = irq_data_get_irq_chip_data(d); 55 int bit_off = d->hwirq; 56 57 writel(1 << bit_off, data->reg_clr); 58 59 irq_chip_ack_parent(d); 60 } 61 62 static void sg2042_msi_irq_compose_msi_msg(struct irq_data *d, struct msi_msg *msg) 63 { 64 struct sg2042_msi_chipdata *data = irq_data_get_irq_chip_data(d); 65 66 msg->address_hi = upper_32_bits(data->doorbell_addr); 67 msg->address_lo = lower_32_bits(data->doorbell_addr); 68 msg->data = 1 << d->hwirq; 69 } 70 71 static const struct irq_chip sg2042_msi_middle_irq_chip = { 72 .name = "SG2042 MSI", 73 .irq_ack = sg2042_msi_irq_ack, 74 .irq_mask = irq_chip_mask_parent, 75 .irq_unmask = irq_chip_unmask_parent, 76 #ifdef CONFIG_SMP 77 .irq_set_affinity = irq_chip_set_affinity_parent, 78 #endif 79 .irq_compose_msi_msg = sg2042_msi_irq_compose_msi_msg, 80 }; 81 82 static int sg2042_msi_parent_domain_alloc(struct irq_domain *domain, unsigned int virq, int hwirq) 83 { 84 struct sg2042_msi_chipdata *data = domain->host_data; 85 struct irq_fwspec fwspec; 86 struct irq_data *d; 87 int ret; 88 89 fwspec.fwnode = domain->parent->fwnode; 90 fwspec.param_count = 2; 91 fwspec.param[0] = data->irq_first + hwirq; 92 fwspec.param[1] = IRQ_TYPE_EDGE_RISING; 93 94 ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec); 95 if (ret) 96 return ret; 97 98 d = irq_domain_get_irq_data(domain->parent, virq); 99 return d->chip->irq_set_type(d, IRQ_TYPE_EDGE_RISING); 100 } 101 102 static int sg2042_msi_middle_domain_alloc(struct irq_domain *domain, unsigned int virq, 103 unsigned int nr_irqs, void *args) 104 { 105 struct sg2042_msi_chipdata *data = domain->host_data; 106 int hwirq, err, i; 107 108 hwirq = sg2042_msi_allocate_hwirq(data, nr_irqs); 109 if (hwirq < 0) 110 return hwirq; 111 112 for (i = 0; i < nr_irqs; i++) { 113 err = sg2042_msi_parent_domain_alloc(domain, virq + i, hwirq + i); 114 if (err) 115 goto err_hwirq; 116 117 irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i, 118 &sg2042_msi_middle_irq_chip, data); 119 } 120 121 return 0; 122 123 err_hwirq: 124 sg2042_msi_free_hwirq(data, hwirq, nr_irqs); 125 irq_domain_free_irqs_parent(domain, virq, i); 126 127 return err; 128 } 129 130 static void sg2042_msi_middle_domain_free(struct irq_domain *domain, unsigned int virq, 131 unsigned int nr_irqs) 132 { 133 struct irq_data *d = irq_domain_get_irq_data(domain, virq); 134 struct sg2042_msi_chipdata *data = irq_data_get_irq_chip_data(d); 135 136 irq_domain_free_irqs_parent(domain, virq, nr_irqs); 137 sg2042_msi_free_hwirq(data, d->hwirq, nr_irqs); 138 } 139 140 static const struct irq_domain_ops sg2042_msi_middle_domain_ops = { 141 .alloc = sg2042_msi_middle_domain_alloc, 142 .free = sg2042_msi_middle_domain_free, 143 .select = msi_lib_irq_domain_select, 144 }; 145 146 #define SG2042_MSI_FLAGS_REQUIRED (MSI_FLAG_USE_DEF_DOM_OPS | \ 147 MSI_FLAG_USE_DEF_CHIP_OPS) 148 149 #define SG2042_MSI_FLAGS_SUPPORTED MSI_GENERIC_FLAGS_MASK 150 151 static const struct msi_parent_ops sg2042_msi_parent_ops = { 152 .required_flags = SG2042_MSI_FLAGS_REQUIRED, 153 .supported_flags = SG2042_MSI_FLAGS_SUPPORTED, 154 .chip_flags = MSI_CHIP_FLAG_SET_ACK, 155 .bus_select_mask = MATCH_PCI_MSI, 156 .bus_select_token = DOMAIN_BUS_NEXUS, 157 .prefix = "SG2042-", 158 .init_dev_msi_info = msi_lib_init_dev_msi_info, 159 }; 160 161 static int sg2042_msi_init_domains(struct sg2042_msi_chipdata *data, 162 struct irq_domain *plic_domain, struct device *dev) 163 { 164 struct fwnode_handle *fwnode = dev_fwnode(dev); 165 struct irq_domain *middle_domain; 166 167 middle_domain = irq_domain_create_hierarchy(plic_domain, 0, data->num_irqs, fwnode, 168 &sg2042_msi_middle_domain_ops, data); 169 if (!middle_domain) { 170 pr_err("Failed to create the MSI middle domain\n"); 171 return -ENOMEM; 172 } 173 174 irq_domain_update_bus_token(middle_domain, DOMAIN_BUS_NEXUS); 175 176 middle_domain->flags |= IRQ_DOMAIN_FLAG_MSI_PARENT; 177 middle_domain->msi_parent_ops = &sg2042_msi_parent_ops; 178 179 return 0; 180 } 181 182 static int sg2042_msi_probe(struct platform_device *pdev) 183 { 184 struct fwnode_reference_args args = { }; 185 struct sg2042_msi_chipdata *data; 186 struct device *dev = &pdev->dev; 187 struct irq_domain *plic_domain; 188 struct resource *res; 189 int ret; 190 191 data = devm_kzalloc(dev, sizeof(struct sg2042_msi_chipdata), GFP_KERNEL); 192 if (!data) 193 return -ENOMEM; 194 195 data->reg_clr = devm_platform_ioremap_resource_byname(pdev, "clr"); 196 if (IS_ERR(data->reg_clr)) { 197 dev_err(dev, "Failed to map clear register\n"); 198 return PTR_ERR(data->reg_clr); 199 } 200 201 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "doorbell"); 202 if (!res) { 203 dev_err(dev, "Failed get resource from set\n"); 204 return -EINVAL; 205 } 206 data->doorbell_addr = res->start; 207 208 ret = fwnode_property_get_reference_args(dev_fwnode(dev), "msi-ranges", 209 "#interrupt-cells", 0, 0, &args); 210 if (ret) { 211 dev_err(dev, "Unable to parse MSI vec base\n"); 212 return ret; 213 } 214 fwnode_handle_put(args.fwnode); 215 216 ret = fwnode_property_get_reference_args(dev_fwnode(dev), "msi-ranges", NULL, 217 args.nargs + 1, 0, &args); 218 if (ret) { 219 dev_err(dev, "Unable to parse MSI vec number\n"); 220 return ret; 221 } 222 223 plic_domain = irq_find_matching_fwnode(args.fwnode, DOMAIN_BUS_ANY); 224 fwnode_handle_put(args.fwnode); 225 if (!plic_domain) { 226 pr_err("Failed to find the PLIC domain\n"); 227 return -ENXIO; 228 } 229 230 data->irq_first = (u32)args.args[0]; 231 data->num_irqs = (u32)args.args[args.nargs - 1]; 232 233 mutex_init(&data->msi_map_lock); 234 235 return sg2042_msi_init_domains(data, plic_domain, dev); 236 } 237 238 static const struct of_device_id sg2042_msi_of_match[] = { 239 { .compatible = "sophgo,sg2042-msi" }, 240 { } 241 }; 242 243 static struct platform_driver sg2042_msi_driver = { 244 .driver = { 245 .name = "sg2042-msi", 246 .of_match_table = sg2042_msi_of_match, 247 }, 248 .probe = sg2042_msi_probe, 249 }; 250 builtin_platform_driver(sg2042_msi_driver); 251