1 /* 2 * Platform driver for the Synopsys DesignWare DMA Controller 3 * 4 * Copyright (C) 2007-2008 Atmel Corporation 5 * Copyright (C) 2010-2011 ST Microelectronics 6 * Copyright (C) 2013 Intel Corporation 7 * 8 * Some parts of this driver are derived from the original dw_dmac. 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License version 2 as 12 * published by the Free Software Foundation. 13 */ 14 15 #include <linux/module.h> 16 #include <linux/device.h> 17 #include <linux/clk.h> 18 #include <linux/pm_runtime.h> 19 #include <linux/platform_device.h> 20 #include <linux/dmaengine.h> 21 #include <linux/dma-mapping.h> 22 #include <linux/of.h> 23 #include <linux/of_dma.h> 24 #include <linux/acpi.h> 25 #include <linux/acpi_dma.h> 26 27 #include "internal.h" 28 29 #define DRV_NAME "dw_dmac" 30 31 static struct dma_chan *dw_dma_of_xlate(struct of_phandle_args *dma_spec, 32 struct of_dma *ofdma) 33 { 34 struct dw_dma *dw = ofdma->of_dma_data; 35 struct dw_dma_slave slave = { 36 .dma_dev = dw->dma.dev, 37 }; 38 dma_cap_mask_t cap; 39 40 if (dma_spec->args_count != 3) 41 return NULL; 42 43 slave.src_id = dma_spec->args[0]; 44 slave.dst_id = dma_spec->args[0]; 45 slave.src_master = dma_spec->args[1]; 46 slave.dst_master = dma_spec->args[2]; 47 48 if (WARN_ON(slave.src_id >= DW_DMA_MAX_NR_REQUESTS || 49 slave.dst_id >= DW_DMA_MAX_NR_REQUESTS || 50 slave.src_master >= dw->nr_masters || 51 slave.dst_master >= dw->nr_masters)) 52 return NULL; 53 54 dma_cap_zero(cap); 55 dma_cap_set(DMA_SLAVE, cap); 56 57 /* TODO: there should be a simpler way to do this */ 58 return dma_request_channel(cap, dw_dma_filter, &slave); 59 } 60 61 #ifdef CONFIG_ACPI 62 static bool dw_dma_acpi_filter(struct dma_chan *chan, void *param) 63 { 64 struct acpi_dma_spec *dma_spec = param; 65 struct dw_dma_slave slave = { 66 .dma_dev = dma_spec->dev, 67 .src_id = dma_spec->slave_id, 68 .dst_id = dma_spec->slave_id, 69 .src_master = 1, 70 .dst_master = 0, 71 }; 72 73 return dw_dma_filter(chan, &slave); 74 } 75 76 static void dw_dma_acpi_controller_register(struct dw_dma *dw) 77 { 78 struct device *dev = dw->dma.dev; 79 struct acpi_dma_filter_info *info; 80 int ret; 81 82 info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL); 83 if (!info) 84 return; 85 86 dma_cap_zero(info->dma_cap); 87 dma_cap_set(DMA_SLAVE, info->dma_cap); 88 info->filter_fn = dw_dma_acpi_filter; 89 90 ret = devm_acpi_dma_controller_register(dev, acpi_dma_simple_xlate, 91 info); 92 if (ret) 93 dev_err(dev, "could not register acpi_dma_controller\n"); 94 } 95 #else /* !CONFIG_ACPI */ 96 static inline void dw_dma_acpi_controller_register(struct dw_dma *dw) {} 97 #endif /* !CONFIG_ACPI */ 98 99 #ifdef CONFIG_OF 100 static struct dw_dma_platform_data * 101 dw_dma_parse_dt(struct platform_device *pdev) 102 { 103 struct device_node *np = pdev->dev.of_node; 104 struct dw_dma_platform_data *pdata; 105 u32 tmp, arr[DW_DMA_MAX_NR_MASTERS]; 106 u32 nr_channels; 107 108 if (!np) { 109 dev_err(&pdev->dev, "Missing DT data\n"); 110 return NULL; 111 } 112 113 if (of_property_read_u32(np, "dma-channels", &nr_channels)) 114 return NULL; 115 116 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); 117 if (!pdata) 118 return NULL; 119 120 pdata->nr_channels = nr_channels; 121 122 if (of_property_read_bool(np, "is_private")) 123 pdata->is_private = true; 124 125 if (!of_property_read_u32(np, "chan_allocation_order", &tmp)) 126 pdata->chan_allocation_order = (unsigned char)tmp; 127 128 if (!of_property_read_u32(np, "chan_priority", &tmp)) 129 pdata->chan_priority = tmp; 130 131 if (!of_property_read_u32(np, "block_size", &tmp)) 132 pdata->block_size = tmp; 133 134 if (!of_property_read_u32(np, "dma-masters", &tmp)) { 135 if (tmp > DW_DMA_MAX_NR_MASTERS) 136 return NULL; 137 138 pdata->nr_masters = tmp; 139 } 140 141 if (!of_property_read_u32_array(np, "data_width", arr, 142 pdata->nr_masters)) 143 for (tmp = 0; tmp < pdata->nr_masters; tmp++) 144 pdata->data_width[tmp] = arr[tmp]; 145 146 return pdata; 147 } 148 #else 149 static inline struct dw_dma_platform_data * 150 dw_dma_parse_dt(struct platform_device *pdev) 151 { 152 return NULL; 153 } 154 #endif 155 156 static int dw_probe(struct platform_device *pdev) 157 { 158 struct dw_dma_chip *chip; 159 struct device *dev = &pdev->dev; 160 struct resource *mem; 161 struct dw_dma_platform_data *pdata; 162 int err; 163 164 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); 165 if (!chip) 166 return -ENOMEM; 167 168 chip->irq = platform_get_irq(pdev, 0); 169 if (chip->irq < 0) 170 return chip->irq; 171 172 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 173 chip->regs = devm_ioremap_resource(dev, mem); 174 if (IS_ERR(chip->regs)) 175 return PTR_ERR(chip->regs); 176 177 err = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); 178 if (err) 179 return err; 180 181 pdata = dev_get_platdata(dev); 182 if (!pdata) 183 pdata = dw_dma_parse_dt(pdev); 184 185 chip->dev = dev; 186 187 chip->clk = devm_clk_get(chip->dev, "hclk"); 188 if (IS_ERR(chip->clk)) 189 return PTR_ERR(chip->clk); 190 err = clk_prepare_enable(chip->clk); 191 if (err) 192 return err; 193 194 pm_runtime_enable(&pdev->dev); 195 196 err = dw_dma_probe(chip, pdata); 197 if (err) 198 goto err_dw_dma_probe; 199 200 platform_set_drvdata(pdev, chip); 201 202 if (pdev->dev.of_node) { 203 err = of_dma_controller_register(pdev->dev.of_node, 204 dw_dma_of_xlate, chip->dw); 205 if (err) 206 dev_err(&pdev->dev, 207 "could not register of_dma_controller\n"); 208 } 209 210 if (ACPI_HANDLE(&pdev->dev)) 211 dw_dma_acpi_controller_register(chip->dw); 212 213 return 0; 214 215 err_dw_dma_probe: 216 pm_runtime_disable(&pdev->dev); 217 clk_disable_unprepare(chip->clk); 218 return err; 219 } 220 221 static int dw_remove(struct platform_device *pdev) 222 { 223 struct dw_dma_chip *chip = platform_get_drvdata(pdev); 224 225 if (pdev->dev.of_node) 226 of_dma_controller_free(pdev->dev.of_node); 227 228 dw_dma_remove(chip); 229 pm_runtime_disable(&pdev->dev); 230 clk_disable_unprepare(chip->clk); 231 232 return 0; 233 } 234 235 static void dw_shutdown(struct platform_device *pdev) 236 { 237 struct dw_dma_chip *chip = platform_get_drvdata(pdev); 238 239 /* 240 * We have to call dw_dma_disable() to stop any ongoing transfer. On 241 * some platforms we can't do that since DMA device is powered off. 242 * Moreover we have no possibility to check if the platform is affected 243 * or not. That's why we call pm_runtime_get_sync() / pm_runtime_put() 244 * unconditionally. On the other hand we can't use 245 * pm_runtime_suspended() because runtime PM framework is not fully 246 * used by the driver. 247 */ 248 pm_runtime_get_sync(chip->dev); 249 dw_dma_disable(chip); 250 pm_runtime_put_sync_suspend(chip->dev); 251 252 clk_disable_unprepare(chip->clk); 253 } 254 255 #ifdef CONFIG_OF 256 static const struct of_device_id dw_dma_of_id_table[] = { 257 { .compatible = "snps,dma-spear1340" }, 258 {} 259 }; 260 MODULE_DEVICE_TABLE(of, dw_dma_of_id_table); 261 #endif 262 263 #ifdef CONFIG_ACPI 264 static const struct acpi_device_id dw_dma_acpi_id_table[] = { 265 { "INTL9C60", 0 }, 266 { } 267 }; 268 MODULE_DEVICE_TABLE(acpi, dw_dma_acpi_id_table); 269 #endif 270 271 #ifdef CONFIG_PM_SLEEP 272 273 static int dw_suspend_late(struct device *dev) 274 { 275 struct platform_device *pdev = to_platform_device(dev); 276 struct dw_dma_chip *chip = platform_get_drvdata(pdev); 277 278 dw_dma_disable(chip); 279 clk_disable_unprepare(chip->clk); 280 281 return 0; 282 } 283 284 static int dw_resume_early(struct device *dev) 285 { 286 struct platform_device *pdev = to_platform_device(dev); 287 struct dw_dma_chip *chip = platform_get_drvdata(pdev); 288 289 clk_prepare_enable(chip->clk); 290 return dw_dma_enable(chip); 291 } 292 293 #endif /* CONFIG_PM_SLEEP */ 294 295 static const struct dev_pm_ops dw_dev_pm_ops = { 296 SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_suspend_late, dw_resume_early) 297 }; 298 299 static struct platform_driver dw_driver = { 300 .probe = dw_probe, 301 .remove = dw_remove, 302 .shutdown = dw_shutdown, 303 .driver = { 304 .name = DRV_NAME, 305 .pm = &dw_dev_pm_ops, 306 .of_match_table = of_match_ptr(dw_dma_of_id_table), 307 .acpi_match_table = ACPI_PTR(dw_dma_acpi_id_table), 308 }, 309 }; 310 311 static int __init dw_init(void) 312 { 313 return platform_driver_register(&dw_driver); 314 } 315 subsys_initcall(dw_init); 316 317 static void __exit dw_exit(void) 318 { 319 platform_driver_unregister(&dw_driver); 320 } 321 module_exit(dw_exit); 322 323 MODULE_LICENSE("GPL v2"); 324 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller platform driver"); 325 MODULE_ALIAS("platform:" DRV_NAME); 326