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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 static struct dma_chan *dw_dma_of_xlate(struct of_phandle_args *dma_spec,
 30                                         struct of_dma *ofdma)
 31 {
 32         struct dw_dma *dw = ofdma->of_dma_data;
 33         struct dw_dma_slave slave = {
 34                 .dma_dev = dw->dma.dev,
 35         };
 36         dma_cap_mask_t cap;
 37 
 38         if (dma_spec->args_count != 3)
 39                 return NULL;
 40 
 41         slave.src_id = dma_spec->args[0];
 42         slave.dst_id = dma_spec->args[0];
 43         slave.src_master = dma_spec->args[1];
 44         slave.dst_master = dma_spec->args[2];
 45 
 46         if (WARN_ON(slave.src_id >= DW_DMA_MAX_NR_REQUESTS ||
 47                     slave.dst_id >= DW_DMA_MAX_NR_REQUESTS ||
 48                     slave.src_master >= dw->nr_masters ||
 49                     slave.dst_master >= dw->nr_masters))
 50                 return NULL;
 51 
 52         dma_cap_zero(cap);
 53         dma_cap_set(DMA_SLAVE, cap);
 54 
 55         /* TODO: there should be a simpler way to do this */
 56         return dma_request_channel(cap, dw_dma_filter, &slave);
 57 }
 58 
 59 #ifdef CONFIG_ACPI
 60 static bool dw_dma_acpi_filter(struct dma_chan *chan, void *param)
 61 {
 62         struct acpi_dma_spec *dma_spec = param;
 63         struct dw_dma_slave slave = {
 64                 .dma_dev = dma_spec->dev,
 65                 .src_id = dma_spec->slave_id,
 66                 .dst_id = dma_spec->slave_id,
 67                 .src_master = 1,
 68                 .dst_master = 0,
 69         };
 70 
 71         return dw_dma_filter(chan, &slave);
 72 }
 73 
 74 static void dw_dma_acpi_controller_register(struct dw_dma *dw)
 75 {
 76         struct device *dev = dw->dma.dev;
 77         struct acpi_dma_filter_info *info;
 78         int ret;
 79 
 80         info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
 81         if (!info)
 82                 return;
 83 
 84         dma_cap_zero(info->dma_cap);
 85         dma_cap_set(DMA_SLAVE, info->dma_cap);
 86         info->filter_fn = dw_dma_acpi_filter;
 87 
 88         ret = devm_acpi_dma_controller_register(dev, acpi_dma_simple_xlate,
 89                                                 info);
 90         if (ret)
 91                 dev_err(dev, "could not register acpi_dma_controller\n");
 92 }
 93 #else /* !CONFIG_ACPI */
 94 static inline void dw_dma_acpi_controller_register(struct dw_dma *dw) {}
 95 #endif /* !CONFIG_ACPI */
 96 
 97 #ifdef CONFIG_OF
 98 static struct dw_dma_platform_data *
 99 dw_dma_parse_dt(struct platform_device *pdev)
100 {
101         struct device_node *np = pdev->dev.of_node;
102         struct dw_dma_platform_data *pdata;
103         u32 tmp, arr[4];
104 
105         if (!np) {
106                 dev_err(&pdev->dev, "Missing DT data\n");
107                 return NULL;
108         }
109 
110         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
111         if (!pdata)
112                 return NULL;
113 
114         if (of_property_read_u32(np, "dma-channels", &pdata->nr_channels))
115                 return NULL;
116 
117         if (of_property_read_bool(np, "is_private"))
118                 pdata->is_private = true;
119 
120         if (!of_property_read_u32(np, "chan_allocation_order", &tmp))
121                 pdata->chan_allocation_order = (unsigned char)tmp;
122 
123         if (!of_property_read_u32(np, "chan_priority", &tmp))
124                 pdata->chan_priority = tmp;
125 
126         if (!of_property_read_u32(np, "block_size", &tmp))
127                 pdata->block_size = tmp;
128 
129         if (!of_property_read_u32(np, "dma-masters", &tmp)) {
130                 if (tmp > 4)
131                         return NULL;
132 
133                 pdata->nr_masters = tmp;
134         }
135 
136         if (!of_property_read_u32_array(np, "data_width", arr,
137                                 pdata->nr_masters))
138                 for (tmp = 0; tmp < pdata->nr_masters; tmp++)
139                         pdata->data_width[tmp] = arr[tmp];
140 
141         return pdata;
142 }
143 #else
144 static inline struct dw_dma_platform_data *
145 dw_dma_parse_dt(struct platform_device *pdev)
146 {
147         return NULL;
148 }
149 #endif
150 
151 static int dw_probe(struct platform_device *pdev)
152 {
153         struct dw_dma_chip *chip;
154         struct device *dev = &pdev->dev;
155         struct resource *mem;
156         struct dw_dma_platform_data *pdata;
157         int err;
158 
159         chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
160         if (!chip)
161                 return -ENOMEM;
162 
163         chip->irq = platform_get_irq(pdev, 0);
164         if (chip->irq < 0)
165                 return chip->irq;
166 
167         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
168         chip->regs = devm_ioremap_resource(dev, mem);
169         if (IS_ERR(chip->regs))
170                 return PTR_ERR(chip->regs);
171 
172         err = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
173         if (err)
174                 return err;
175 
176         pdata = dev_get_platdata(dev);
177         if (!pdata)
178                 pdata = dw_dma_parse_dt(pdev);
179 
180         chip->dev = dev;
181 
182         chip->clk = devm_clk_get(chip->dev, "hclk");
183         if (IS_ERR(chip->clk))
184                 return PTR_ERR(chip->clk);
185         err = clk_prepare_enable(chip->clk);
186         if (err)
187                 return err;
188 
189         pm_runtime_enable(&pdev->dev);
190 
191         err = dw_dma_probe(chip, pdata);
192         if (err)
193                 goto err_dw_dma_probe;
194 
195         platform_set_drvdata(pdev, chip);
196 
197         if (pdev->dev.of_node) {
198                 err = of_dma_controller_register(pdev->dev.of_node,
199                                                  dw_dma_of_xlate, chip->dw);
200                 if (err)
201                         dev_err(&pdev->dev,
202                                 "could not register of_dma_controller\n");
203         }
204 
205         if (ACPI_HANDLE(&pdev->dev))
206                 dw_dma_acpi_controller_register(chip->dw);
207 
208         return 0;
209 
210 err_dw_dma_probe:
211         pm_runtime_disable(&pdev->dev);
212         clk_disable_unprepare(chip->clk);
213         return err;
214 }
215 
216 static int dw_remove(struct platform_device *pdev)
217 {
218         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
219 
220         if (pdev->dev.of_node)
221                 of_dma_controller_free(pdev->dev.of_node);
222 
223         dw_dma_remove(chip);
224         pm_runtime_disable(&pdev->dev);
225         clk_disable_unprepare(chip->clk);
226 
227         return 0;
228 }
229 
230 static void dw_shutdown(struct platform_device *pdev)
231 {
232         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
233 
234         dw_dma_disable(chip);
235         clk_disable_unprepare(chip->clk);
236 }
237 
238 #ifdef CONFIG_OF
239 static const struct of_device_id dw_dma_of_id_table[] = {
240         { .compatible = "snps,dma-spear1340" },
241         {}
242 };
243 MODULE_DEVICE_TABLE(of, dw_dma_of_id_table);
244 #endif
245 
246 #ifdef CONFIG_ACPI
247 static const struct acpi_device_id dw_dma_acpi_id_table[] = {
248         { "INTL9C60", 0 },
249         { }
250 };
251 MODULE_DEVICE_TABLE(acpi, dw_dma_acpi_id_table);
252 #endif
253 
254 #ifdef CONFIG_PM_SLEEP
255 
256 static int dw_suspend_late(struct device *dev)
257 {
258         struct platform_device *pdev = to_platform_device(dev);
259         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
260 
261         dw_dma_disable(chip);
262         clk_disable_unprepare(chip->clk);
263 
264         return 0;
265 }
266 
267 static int dw_resume_early(struct device *dev)
268 {
269         struct platform_device *pdev = to_platform_device(dev);
270         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
271 
272         clk_prepare_enable(chip->clk);
273         return dw_dma_enable(chip);
274 }
275 
276 #endif /* CONFIG_PM_SLEEP */
277 
278 static const struct dev_pm_ops dw_dev_pm_ops = {
279         SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_suspend_late, dw_resume_early)
280 };
281 
282 static struct platform_driver dw_driver = {
283         .probe          = dw_probe,
284         .remove         = dw_remove,
285         .shutdown       = dw_shutdown,
286         .driver = {
287                 .name   = "dw_dmac",
288                 .pm     = &dw_dev_pm_ops,
289                 .of_match_table = of_match_ptr(dw_dma_of_id_table),
290                 .acpi_match_table = ACPI_PTR(dw_dma_acpi_id_table),
291         },
292 };
293 
294 static int __init dw_init(void)
295 {
296         return platform_driver_register(&dw_driver);
297 }
298 subsys_initcall(dw_init);
299 
300 static void __exit dw_exit(void)
301 {
302         platform_driver_unregister(&dw_driver);
303 }
304 module_exit(dw_exit);
305 
306 MODULE_LICENSE("GPL v2");
307 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller platform driver");
308 

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