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Linux/drivers/dma/dw/platform.c

  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 
107         if (!np) {
108                 dev_err(&pdev->dev, "Missing DT data\n");
109                 return NULL;
110         }
111 
112         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
113         if (!pdata)
114                 return NULL;
115 
116         if (of_property_read_u32(np, "dma-channels", &pdata->nr_channels))
117                 return NULL;
118 
119         if (of_property_read_bool(np, "is_private"))
120                 pdata->is_private = true;
121 
122         if (!of_property_read_u32(np, "chan_allocation_order", &tmp))
123                 pdata->chan_allocation_order = (unsigned char)tmp;
124 
125         if (!of_property_read_u32(np, "chan_priority", &tmp))
126                 pdata->chan_priority = tmp;
127 
128         if (!of_property_read_u32(np, "block_size", &tmp))
129                 pdata->block_size = tmp;
130 
131         if (!of_property_read_u32(np, "dma-masters", &tmp)) {
132                 if (tmp > DW_DMA_MAX_NR_MASTERS)
133                         return NULL;
134 
135                 pdata->nr_masters = tmp;
136         }
137 
138         if (!of_property_read_u32_array(np, "data_width", arr,
139                                 pdata->nr_masters))
140                 for (tmp = 0; tmp < pdata->nr_masters; tmp++)
141                         pdata->data_width[tmp] = arr[tmp];
142 
143         return pdata;
144 }
145 #else
146 static inline struct dw_dma_platform_data *
147 dw_dma_parse_dt(struct platform_device *pdev)
148 {
149         return NULL;
150 }
151 #endif
152 
153 static int dw_probe(struct platform_device *pdev)
154 {
155         struct dw_dma_chip *chip;
156         struct device *dev = &pdev->dev;
157         struct resource *mem;
158         struct dw_dma_platform_data *pdata;
159         int err;
160 
161         chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
162         if (!chip)
163                 return -ENOMEM;
164 
165         chip->irq = platform_get_irq(pdev, 0);
166         if (chip->irq < 0)
167                 return chip->irq;
168 
169         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
170         chip->regs = devm_ioremap_resource(dev, mem);
171         if (IS_ERR(chip->regs))
172                 return PTR_ERR(chip->regs);
173 
174         err = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
175         if (err)
176                 return err;
177 
178         pdata = dev_get_platdata(dev);
179         if (!pdata)
180                 pdata = dw_dma_parse_dt(pdev);
181 
182         chip->dev = dev;
183 
184         chip->clk = devm_clk_get(chip->dev, "hclk");
185         if (IS_ERR(chip->clk))
186                 return PTR_ERR(chip->clk);
187         err = clk_prepare_enable(chip->clk);
188         if (err)
189                 return err;
190 
191         pm_runtime_enable(&pdev->dev);
192 
193         err = dw_dma_probe(chip, pdata);
194         if (err)
195                 goto err_dw_dma_probe;
196 
197         platform_set_drvdata(pdev, chip);
198 
199         if (pdev->dev.of_node) {
200                 err = of_dma_controller_register(pdev->dev.of_node,
201                                                  dw_dma_of_xlate, chip->dw);
202                 if (err)
203                         dev_err(&pdev->dev,
204                                 "could not register of_dma_controller\n");
205         }
206 
207         if (ACPI_HANDLE(&pdev->dev))
208                 dw_dma_acpi_controller_register(chip->dw);
209 
210         return 0;
211 
212 err_dw_dma_probe:
213         pm_runtime_disable(&pdev->dev);
214         clk_disable_unprepare(chip->clk);
215         return err;
216 }
217 
218 static int dw_remove(struct platform_device *pdev)
219 {
220         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
221 
222         if (pdev->dev.of_node)
223                 of_dma_controller_free(pdev->dev.of_node);
224 
225         dw_dma_remove(chip);
226         pm_runtime_disable(&pdev->dev);
227         clk_disable_unprepare(chip->clk);
228 
229         return 0;
230 }
231 
232 static void dw_shutdown(struct platform_device *pdev)
233 {
234         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
235 
236         dw_dma_disable(chip);
237         clk_disable_unprepare(chip->clk);
238 }
239 
240 #ifdef CONFIG_OF
241 static const struct of_device_id dw_dma_of_id_table[] = {
242         { .compatible = "snps,dma-spear1340" },
243         {}
244 };
245 MODULE_DEVICE_TABLE(of, dw_dma_of_id_table);
246 #endif
247 
248 #ifdef CONFIG_ACPI
249 static const struct acpi_device_id dw_dma_acpi_id_table[] = {
250         { "INTL9C60", 0 },
251         { }
252 };
253 MODULE_DEVICE_TABLE(acpi, dw_dma_acpi_id_table);
254 #endif
255 
256 #ifdef CONFIG_PM_SLEEP
257 
258 static int dw_suspend_late(struct device *dev)
259 {
260         struct platform_device *pdev = to_platform_device(dev);
261         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
262 
263         dw_dma_disable(chip);
264         clk_disable_unprepare(chip->clk);
265 
266         return 0;
267 }
268 
269 static int dw_resume_early(struct device *dev)
270 {
271         struct platform_device *pdev = to_platform_device(dev);
272         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
273 
274         clk_prepare_enable(chip->clk);
275         return dw_dma_enable(chip);
276 }
277 
278 #endif /* CONFIG_PM_SLEEP */
279 
280 static const struct dev_pm_ops dw_dev_pm_ops = {
281         SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_suspend_late, dw_resume_early)
282 };
283 
284 static struct platform_driver dw_driver = {
285         .probe          = dw_probe,
286         .remove         = dw_remove,
287         .shutdown       = dw_shutdown,
288         .driver = {
289                 .name   = DRV_NAME,
290                 .pm     = &dw_dev_pm_ops,
291                 .of_match_table = of_match_ptr(dw_dma_of_id_table),
292                 .acpi_match_table = ACPI_PTR(dw_dma_acpi_id_table),
293         },
294 };
295 
296 static int __init dw_init(void)
297 {
298         return platform_driver_register(&dw_driver);
299 }
300 subsys_initcall(dw_init);
301 
302 static void __exit dw_exit(void)
303 {
304         platform_driver_unregister(&dw_driver);
305 }
306 module_exit(dw_exit);
307 
308 MODULE_LICENSE("GPL v2");
309 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller platform driver");
310 MODULE_ALIAS("platform:" DRV_NAME);
311 

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