blob: b552949da14b20a3755e540bcc637dcaf661a75e [file] [log] [blame]
Thomas Gleixner1802d0b2019-05-27 08:55:21 +02001// SPDX-License-Identifier: GPL-2.0-only
Pierre-Yves MORDRETdf7e7622017-09-22 09:31:30 +02002/*
3 *
4 * Copyright (C) STMicroelectronics SA 2017
5 * Author(s): M'boumba Cedric Madianga <cedric.madianga@gmail.com>
6 * Pierre-Yves Mordret <pierre-yves.mordret@st.com>
7 *
Pierre-Yves MORDRETdf7e7622017-09-22 09:31:30 +02008 * DMA Router driver for STM32 DMA MUX
9 *
10 * Based on TI DMA Crossbar driver
Pierre-Yves MORDRETdf7e7622017-09-22 09:31:30 +020011 */
12
13#include <linux/clk.h>
14#include <linux/delay.h>
15#include <linux/err.h>
16#include <linux/init.h>
17#include <linux/module.h>
18#include <linux/of_device.h>
19#include <linux/of_dma.h>
Pierre-Yves MORDRET4f3ceca2019-01-03 11:17:09 +010020#include <linux/pm_runtime.h>
Pierre-Yves MORDRETdf7e7622017-09-22 09:31:30 +020021#include <linux/reset.h>
22#include <linux/slab.h>
23#include <linux/spinlock.h>
24
25#define STM32_DMAMUX_CCR(x) (0x4 * (x))
26#define STM32_DMAMUX_MAX_DMA_REQUESTS 32
27#define STM32_DMAMUX_MAX_REQUESTS 255
28
29struct stm32_dmamux {
30 u32 master;
31 u32 request;
32 u32 chan_id;
33};
34
35struct stm32_dmamux_data {
36 struct dma_router dmarouter;
37 struct clk *clk;
38 struct reset_control *rst;
39 void __iomem *iomem;
40 u32 dma_requests; /* Number of DMA requests connected to DMAMUX */
41 u32 dmamux_requests; /* Number of DMA requests routed toward DMAs */
42 spinlock_t lock; /* Protects register access */
43 unsigned long *dma_inuse; /* Used DMA channel */
44 u32 dma_reqs[]; /* Number of DMA Request per DMA masters.
45 * [0] holds number of DMA Masters.
46 * To be kept at very end end of this structure
47 */
48};
49
50static inline u32 stm32_dmamux_read(void __iomem *iomem, u32 reg)
51{
52 return readl_relaxed(iomem + reg);
53}
54
55static inline void stm32_dmamux_write(void __iomem *iomem, u32 reg, u32 val)
56{
57 writel_relaxed(val, iomem + reg);
58}
59
60static void stm32_dmamux_free(struct device *dev, void *route_data)
61{
62 struct stm32_dmamux_data *dmamux = dev_get_drvdata(dev);
63 struct stm32_dmamux *mux = route_data;
64 unsigned long flags;
65
66 /* Clear dma request */
67 spin_lock_irqsave(&dmamux->lock, flags);
68
69 stm32_dmamux_write(dmamux->iomem, STM32_DMAMUX_CCR(mux->chan_id), 0);
70 clear_bit(mux->chan_id, dmamux->dma_inuse);
71
Pierre-Yves MORDRET4f3ceca2019-01-03 11:17:09 +010072 pm_runtime_put_sync(dev);
Pierre-Yves MORDRETdf7e7622017-09-22 09:31:30 +020073
74 spin_unlock_irqrestore(&dmamux->lock, flags);
75
76 dev_dbg(dev, "Unmapping DMAMUX(%u) to DMA%u(%u)\n",
77 mux->request, mux->master, mux->chan_id);
78
79 kfree(mux);
80}
81
82static void *stm32_dmamux_route_allocate(struct of_phandle_args *dma_spec,
83 struct of_dma *ofdma)
84{
85 struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
86 struct stm32_dmamux_data *dmamux = platform_get_drvdata(pdev);
87 struct stm32_dmamux *mux;
88 u32 i, min, max;
89 int ret;
90 unsigned long flags;
91
92 if (dma_spec->args_count != 3) {
93 dev_err(&pdev->dev, "invalid number of dma mux args\n");
94 return ERR_PTR(-EINVAL);
95 }
96
97 if (dma_spec->args[0] > dmamux->dmamux_requests) {
98 dev_err(&pdev->dev, "invalid mux request number: %d\n",
99 dma_spec->args[0]);
100 return ERR_PTR(-EINVAL);
101 }
102
103 mux = kzalloc(sizeof(*mux), GFP_KERNEL);
104 if (!mux)
105 return ERR_PTR(-ENOMEM);
106
107 spin_lock_irqsave(&dmamux->lock, flags);
108 mux->chan_id = find_first_zero_bit(dmamux->dma_inuse,
109 dmamux->dma_requests);
Pierre-Yves MORDRETdf7e7622017-09-22 09:31:30 +0200110
111 if (mux->chan_id == dmamux->dma_requests) {
Pierre-Yves MORDRET3e4543b2018-03-13 17:55:35 +0100112 spin_unlock_irqrestore(&dmamux->lock, flags);
Pierre-Yves MORDRETdf7e7622017-09-22 09:31:30 +0200113 dev_err(&pdev->dev, "Run out of free DMA requests\n");
114 ret = -ENOMEM;
Pierre-Yves MORDRET3e4543b2018-03-13 17:55:35 +0100115 goto error_chan_id;
Pierre-Yves MORDRETdf7e7622017-09-22 09:31:30 +0200116 }
Pierre-Yves MORDRET3e4543b2018-03-13 17:55:35 +0100117 set_bit(mux->chan_id, dmamux->dma_inuse);
118 spin_unlock_irqrestore(&dmamux->lock, flags);
Pierre-Yves MORDRETdf7e7622017-09-22 09:31:30 +0200119
120 /* Look for DMA Master */
121 for (i = 1, min = 0, max = dmamux->dma_reqs[i];
122 i <= dmamux->dma_reqs[0];
123 min += dmamux->dma_reqs[i], max += dmamux->dma_reqs[++i])
124 if (mux->chan_id < max)
125 break;
126 mux->master = i - 1;
127
128 /* The of_node_put() will be done in of_dma_router_xlate function */
129 dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", i - 1);
130 if (!dma_spec->np) {
131 dev_err(&pdev->dev, "can't get dma master\n");
132 ret = -EINVAL;
133 goto error;
134 }
135
136 /* Set dma request */
137 spin_lock_irqsave(&dmamux->lock, flags);
Pierre-Yves MORDRET4f3ceca2019-01-03 11:17:09 +0100138 ret = pm_runtime_get_sync(&pdev->dev);
139 if (ret < 0) {
140 spin_unlock_irqrestore(&dmamux->lock, flags);
141 goto error;
Pierre-Yves MORDRETdf7e7622017-09-22 09:31:30 +0200142 }
143 spin_unlock_irqrestore(&dmamux->lock, flags);
144
145 mux->request = dma_spec->args[0];
146
147 /* craft DMA spec */
148 dma_spec->args[3] = dma_spec->args[2];
149 dma_spec->args[2] = dma_spec->args[1];
150 dma_spec->args[1] = 0;
151 dma_spec->args[0] = mux->chan_id - min;
152 dma_spec->args_count = 4;
153
154 stm32_dmamux_write(dmamux->iomem, STM32_DMAMUX_CCR(mux->chan_id),
155 mux->request);
156 dev_dbg(&pdev->dev, "Mapping DMAMUX(%u) to DMA%u(%u)\n",
157 mux->request, mux->master, mux->chan_id);
158
159 return mux;
160
161error:
162 clear_bit(mux->chan_id, dmamux->dma_inuse);
Pierre-Yves MORDRET3e4543b2018-03-13 17:55:35 +0100163
164error_chan_id:
Pierre-Yves MORDRETdf7e7622017-09-22 09:31:30 +0200165 kfree(mux);
166 return ERR_PTR(ret);
167}
168
169static const struct of_device_id stm32_stm32dma_master_match[] = {
170 { .compatible = "st,stm32-dma", },
171 {},
172};
173
174static int stm32_dmamux_probe(struct platform_device *pdev)
175{
176 struct device_node *node = pdev->dev.of_node;
177 const struct of_device_id *match;
178 struct device_node *dma_node;
179 struct stm32_dmamux_data *stm32_dmamux;
180 struct resource *res;
181 void __iomem *iomem;
182 int i, count, ret;
183 u32 dma_req;
184
185 if (!node)
186 return -ENODEV;
187
188 count = device_property_read_u32_array(&pdev->dev, "dma-masters",
189 NULL, 0);
190 if (count < 0) {
191 dev_err(&pdev->dev, "Can't get DMA master(s) node\n");
192 return -ENODEV;
193 }
194
195 stm32_dmamux = devm_kzalloc(&pdev->dev, sizeof(*stm32_dmamux) +
196 sizeof(u32) * (count + 1), GFP_KERNEL);
197 if (!stm32_dmamux)
198 return -ENOMEM;
199
200 dma_req = 0;
201 for (i = 1; i <= count; i++) {
202 dma_node = of_parse_phandle(node, "dma-masters", i - 1);
203
204 match = of_match_node(stm32_stm32dma_master_match, dma_node);
205 if (!match) {
206 dev_err(&pdev->dev, "DMA master is not supported\n");
207 of_node_put(dma_node);
208 return -EINVAL;
209 }
210
211 if (of_property_read_u32(dma_node, "dma-requests",
212 &stm32_dmamux->dma_reqs[i])) {
213 dev_info(&pdev->dev,
214 "Missing MUX output information, using %u.\n",
215 STM32_DMAMUX_MAX_DMA_REQUESTS);
216 stm32_dmamux->dma_reqs[i] =
217 STM32_DMAMUX_MAX_DMA_REQUESTS;
218 }
219 dma_req += stm32_dmamux->dma_reqs[i];
220 of_node_put(dma_node);
221 }
222
223 if (dma_req > STM32_DMAMUX_MAX_DMA_REQUESTS) {
224 dev_err(&pdev->dev, "Too many DMA Master Requests to manage\n");
225 return -ENODEV;
226 }
227
228 stm32_dmamux->dma_requests = dma_req;
229 stm32_dmamux->dma_reqs[0] = count;
230 stm32_dmamux->dma_inuse = devm_kcalloc(&pdev->dev,
231 BITS_TO_LONGS(dma_req),
232 sizeof(unsigned long),
233 GFP_KERNEL);
234 if (!stm32_dmamux->dma_inuse)
235 return -ENOMEM;
236
237 if (device_property_read_u32(&pdev->dev, "dma-requests",
238 &stm32_dmamux->dmamux_requests)) {
239 stm32_dmamux->dmamux_requests = STM32_DMAMUX_MAX_REQUESTS;
240 dev_warn(&pdev->dev, "DMAMUX defaulting on %u requests\n",
241 stm32_dmamux->dmamux_requests);
242 }
Pierre-Yves MORDRET4f3ceca2019-01-03 11:17:09 +0100243 pm_runtime_get_noresume(&pdev->dev);
Pierre-Yves MORDRETdf7e7622017-09-22 09:31:30 +0200244
245 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
Pierre-Yves MORDRETdf7e7622017-09-22 09:31:30 +0200246 iomem = devm_ioremap_resource(&pdev->dev, res);
Dan Carpenter4219ff32017-10-03 13:54:50 +0300247 if (IS_ERR(iomem))
248 return PTR_ERR(iomem);
Pierre-Yves MORDRETdf7e7622017-09-22 09:31:30 +0200249
250 spin_lock_init(&stm32_dmamux->lock);
251
252 stm32_dmamux->clk = devm_clk_get(&pdev->dev, NULL);
253 if (IS_ERR(stm32_dmamux->clk)) {
254 ret = PTR_ERR(stm32_dmamux->clk);
255 if (ret == -EPROBE_DEFER)
256 dev_info(&pdev->dev, "Missing controller clock\n");
257 return ret;
258 }
259
260 stm32_dmamux->rst = devm_reset_control_get(&pdev->dev, NULL);
261 if (!IS_ERR(stm32_dmamux->rst)) {
262 reset_control_assert(stm32_dmamux->rst);
263 udelay(2);
264 reset_control_deassert(stm32_dmamux->rst);
265 }
266
267 stm32_dmamux->iomem = iomem;
268 stm32_dmamux->dmarouter.dev = &pdev->dev;
269 stm32_dmamux->dmarouter.route_free = stm32_dmamux_free;
270
271 platform_set_drvdata(pdev, stm32_dmamux);
Pierre-Yves MORDRET4f3ceca2019-01-03 11:17:09 +0100272 pm_runtime_set_active(&pdev->dev);
273 pm_runtime_enable(&pdev->dev);
Pierre-Yves MORDRETdf7e7622017-09-22 09:31:30 +0200274
275 if (!IS_ERR(stm32_dmamux->clk)) {
276 ret = clk_prepare_enable(stm32_dmamux->clk);
277 if (ret < 0) {
278 dev_err(&pdev->dev, "clk_prep_enable error: %d\n", ret);
279 return ret;
280 }
281 }
282
Pierre-Yves MORDRET4f3ceca2019-01-03 11:17:09 +0100283 pm_runtime_get_noresume(&pdev->dev);
284
Pierre-Yves MORDRETdf7e7622017-09-22 09:31:30 +0200285 /* Reset the dmamux */
286 for (i = 0; i < stm32_dmamux->dma_requests; i++)
287 stm32_dmamux_write(stm32_dmamux->iomem, STM32_DMAMUX_CCR(i), 0);
288
Pierre-Yves MORDRET4f3ceca2019-01-03 11:17:09 +0100289 pm_runtime_put(&pdev->dev);
Pierre-Yves MORDRETdf7e7622017-09-22 09:31:30 +0200290
291 return of_dma_router_register(node, stm32_dmamux_route_allocate,
292 &stm32_dmamux->dmarouter);
293}
294
Pierre-Yves MORDRET4f3ceca2019-01-03 11:17:09 +0100295#ifdef CONFIG_PM
296static int stm32_dmamux_runtime_suspend(struct device *dev)
297{
Weitao Hou7b11ef92019-05-26 15:13:24 +0800298 struct platform_device *pdev = to_platform_device(dev);
Pierre-Yves MORDRET4f3ceca2019-01-03 11:17:09 +0100299 struct stm32_dmamux_data *stm32_dmamux = platform_get_drvdata(pdev);
300
301 clk_disable_unprepare(stm32_dmamux->clk);
302
303 return 0;
304}
305
306static int stm32_dmamux_runtime_resume(struct device *dev)
307{
Weitao Hou7b11ef92019-05-26 15:13:24 +0800308 struct platform_device *pdev = to_platform_device(dev);
Pierre-Yves MORDRET4f3ceca2019-01-03 11:17:09 +0100309 struct stm32_dmamux_data *stm32_dmamux = platform_get_drvdata(pdev);
310 int ret;
311
312 ret = clk_prepare_enable(stm32_dmamux->clk);
313 if (ret) {
314 dev_err(&pdev->dev, "failed to prepare_enable clock\n");
315 return ret;
316 }
317
318 return 0;
319}
320#endif
321
322static const struct dev_pm_ops stm32_dmamux_pm_ops = {
323 SET_RUNTIME_PM_OPS(stm32_dmamux_runtime_suspend,
324 stm32_dmamux_runtime_resume, NULL)
325};
326
Pierre-Yves MORDRETdf7e7622017-09-22 09:31:30 +0200327static const struct of_device_id stm32_dmamux_match[] = {
328 { .compatible = "st,stm32h7-dmamux" },
329 {},
330};
331
332static struct platform_driver stm32_dmamux_driver = {
333 .probe = stm32_dmamux_probe,
334 .driver = {
335 .name = "stm32-dmamux",
336 .of_match_table = stm32_dmamux_match,
Pierre-Yves MORDRET4f3ceca2019-01-03 11:17:09 +0100337 .pm = &stm32_dmamux_pm_ops,
Pierre-Yves MORDRETdf7e7622017-09-22 09:31:30 +0200338 },
339};
340
341static int __init stm32_dmamux_init(void)
342{
343 return platform_driver_register(&stm32_dmamux_driver);
344}
345arch_initcall(stm32_dmamux_init);
346
347MODULE_DESCRIPTION("DMA Router driver for STM32 DMA MUX");
348MODULE_AUTHOR("M'boumba Cedric Madianga <cedric.madianga@gmail.com>");
349MODULE_AUTHOR("Pierre-Yves Mordret <pierre-yves.mordret@st.com>");
350MODULE_LICENSE("GPL v2");