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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.m_master = dma_spec->args[1];
 46         slave.p_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.m_master >= dw->pdata->nr_masters ||
 51                     slave.p_master >= dw->pdata->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                 .m_master = 0,
 70                 .p_master = 1,
 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_masters;
107         u32 nr_channels;
108 
109         if (!np) {
110                 dev_err(&pdev->dev, "Missing DT data\n");
111                 return NULL;
112         }
113 
114         if (of_property_read_u32(np, "dma-masters", &nr_masters))
115                 return NULL;
116         if (nr_masters < 1 || nr_masters > DW_DMA_MAX_NR_MASTERS)
117                 return NULL;
118 
119         if (of_property_read_u32(np, "dma-channels", &nr_channels))
120                 return NULL;
121 
122         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
123         if (!pdata)
124                 return NULL;
125 
126         pdata->nr_masters = nr_masters;
127         pdata->nr_channels = nr_channels;
128 
129         if (of_property_read_bool(np, "is_private"))
130                 pdata->is_private = true;
131 
132         if (!of_property_read_u32(np, "chan_allocation_order", &tmp))
133                 pdata->chan_allocation_order = (unsigned char)tmp;
134 
135         if (!of_property_read_u32(np, "chan_priority", &tmp))
136                 pdata->chan_priority = tmp;
137 
138         if (!of_property_read_u32(np, "block_size", &tmp))
139                 pdata->block_size = tmp;
140 
141         if (!of_property_read_u32_array(np, "data-width", arr, nr_masters)) {
142                 for (tmp = 0; tmp < nr_masters; tmp++)
143                         pdata->data_width[tmp] = arr[tmp];
144         } else if (!of_property_read_u32_array(np, "data_width", arr, nr_masters)) {
145                 for (tmp = 0; tmp < nr_masters; tmp++)
146                         pdata->data_width[tmp] = BIT(arr[tmp] & 0x07);
147         }
148 
149         return pdata;
150 }
151 #else
152 static inline struct dw_dma_platform_data *
153 dw_dma_parse_dt(struct platform_device *pdev)
154 {
155         return NULL;
156 }
157 #endif
158 
159 static int dw_probe(struct platform_device *pdev)
160 {
161         struct dw_dma_chip *chip;
162         struct device *dev = &pdev->dev;
163         struct resource *mem;
164         const struct dw_dma_platform_data *pdata;
165         int err;
166 
167         chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
168         if (!chip)
169                 return -ENOMEM;
170 
171         chip->irq = platform_get_irq(pdev, 0);
172         if (chip->irq < 0)
173                 return chip->irq;
174 
175         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
176         chip->regs = devm_ioremap_resource(dev, mem);
177         if (IS_ERR(chip->regs))
178                 return PTR_ERR(chip->regs);
179 
180         err = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
181         if (err)
182                 return err;
183 
184         pdata = dev_get_platdata(dev);
185         if (!pdata)
186                 pdata = dw_dma_parse_dt(pdev);
187 
188         chip->dev = dev;
189         chip->pdata = pdata;
190 
191         chip->clk = devm_clk_get(chip->dev, "hclk");
192         if (IS_ERR(chip->clk))
193                 return PTR_ERR(chip->clk);
194         err = clk_prepare_enable(chip->clk);
195         if (err)
196                 return err;
197 
198         pm_runtime_enable(&pdev->dev);
199 
200         err = dw_dma_probe(chip);
201         if (err)
202                 goto err_dw_dma_probe;
203 
204         platform_set_drvdata(pdev, chip);
205 
206         if (pdev->dev.of_node) {
207                 err = of_dma_controller_register(pdev->dev.of_node,
208                                                  dw_dma_of_xlate, chip->dw);
209                 if (err)
210                         dev_err(&pdev->dev,
211                                 "could not register of_dma_controller\n");
212         }
213 
214         if (ACPI_HANDLE(&pdev->dev))
215                 dw_dma_acpi_controller_register(chip->dw);
216 
217         return 0;
218 
219 err_dw_dma_probe:
220         pm_runtime_disable(&pdev->dev);
221         clk_disable_unprepare(chip->clk);
222         return err;
223 }
224 
225 static int dw_remove(struct platform_device *pdev)
226 {
227         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
228 
229         if (pdev->dev.of_node)
230                 of_dma_controller_free(pdev->dev.of_node);
231 
232         dw_dma_remove(chip);
233         pm_runtime_disable(&pdev->dev);
234         clk_disable_unprepare(chip->clk);
235 
236         return 0;
237 }
238 
239 static void dw_shutdown(struct platform_device *pdev)
240 {
241         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
242 
243         /*
244          * We have to call dw_dma_disable() to stop any ongoing transfer. On
245          * some platforms we can't do that since DMA device is powered off.
246          * Moreover we have no possibility to check if the platform is affected
247          * or not. That's why we call pm_runtime_get_sync() / pm_runtime_put()
248          * unconditionally. On the other hand we can't use
249          * pm_runtime_suspended() because runtime PM framework is not fully
250          * used by the driver.
251          */
252         pm_runtime_get_sync(chip->dev);
253         dw_dma_disable(chip);
254         pm_runtime_put_sync_suspend(chip->dev);
255 
256         clk_disable_unprepare(chip->clk);
257 }
258 
259 #ifdef CONFIG_OF
260 static const struct of_device_id dw_dma_of_id_table[] = {
261         { .compatible = "snps,dma-spear1340" },
262         {}
263 };
264 MODULE_DEVICE_TABLE(of, dw_dma_of_id_table);
265 #endif
266 
267 #ifdef CONFIG_ACPI
268 static const struct acpi_device_id dw_dma_acpi_id_table[] = {
269         { "INTL9C60", 0 },
270         { }
271 };
272 MODULE_DEVICE_TABLE(acpi, dw_dma_acpi_id_table);
273 #endif
274 
275 #ifdef CONFIG_PM_SLEEP
276 
277 static int dw_suspend_late(struct device *dev)
278 {
279         struct platform_device *pdev = to_platform_device(dev);
280         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
281 
282         dw_dma_disable(chip);
283         clk_disable_unprepare(chip->clk);
284 
285         return 0;
286 }
287 
288 static int dw_resume_early(struct device *dev)
289 {
290         struct platform_device *pdev = to_platform_device(dev);
291         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
292 
293         clk_prepare_enable(chip->clk);
294         return dw_dma_enable(chip);
295 }
296 
297 #endif /* CONFIG_PM_SLEEP */
298 
299 static const struct dev_pm_ops dw_dev_pm_ops = {
300         SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_suspend_late, dw_resume_early)
301 };
302 
303 static struct platform_driver dw_driver = {
304         .probe          = dw_probe,
305         .remove         = dw_remove,
306         .shutdown       = dw_shutdown,
307         .driver = {
308                 .name   = DRV_NAME,
309                 .pm     = &dw_dev_pm_ops,
310                 .of_match_table = of_match_ptr(dw_dma_of_id_table),
311                 .acpi_match_table = ACPI_PTR(dw_dma_acpi_id_table),
312         },
313 };
314 
315 static int __init dw_init(void)
316 {
317         return platform_driver_register(&dw_driver);
318 }
319 subsys_initcall(dw_init);
320 
321 static void __exit dw_exit(void)
322 {
323         platform_driver_unregister(&dw_driver);
324 }
325 module_exit(dw_exit);
326 
327 MODULE_LICENSE("GPL v2");
328 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller platform driver");
329 MODULE_ALIAS("platform:" DRV_NAME);
330 

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