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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         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 

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