1 /*
2 * Marvell EBU SoC Device Bus Controller
3 * (memory controller for NOR/NAND/SRAM/FPGA devices)
4 *
5 * Copyright (C) 2013-2014 Marvell
6 *
7 * This program is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation version 2 of the License.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 *
19 */
20
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/slab.h>
24 #include <linux/err.h>
25 #include <linux/io.h>
26 #include <linux/clk.h>
27 #include <linux/mbus.h>
28 #include <linux/of_platform.h>
29 #include <linux/of_address.h>
30 #include <linux/platform_device.h>
31
32 /* Register definitions */
33 #define ARMADA_DEV_WIDTH_SHIFT 30
34 #define ARMADA_BADR_SKEW_SHIFT 28
35 #define ARMADA_RD_HOLD_SHIFT 23
36 #define ARMADA_ACC_NEXT_SHIFT 17
37 #define ARMADA_RD_SETUP_SHIFT 12
38 #define ARMADA_ACC_FIRST_SHIFT 6
39
40 #define ARMADA_SYNC_ENABLE_SHIFT 24
41 #define ARMADA_WR_HIGH_SHIFT 16
42 #define ARMADA_WR_LOW_SHIFT 8
43
44 #define ARMADA_READ_PARAM_OFFSET 0x0
45 #define ARMADA_WRITE_PARAM_OFFSET 0x4
46
47 #define ORION_RESERVED (0x2 << 30)
48 #define ORION_BADR_SKEW_SHIFT 28
49 #define ORION_WR_HIGH_EXT_BIT BIT(27)
50 #define ORION_WR_HIGH_EXT_MASK 0x8
51 #define ORION_WR_LOW_EXT_BIT BIT(26)
52 #define ORION_WR_LOW_EXT_MASK 0x8
53 #define ORION_ALE_WR_EXT_BIT BIT(25)
54 #define ORION_ALE_WR_EXT_MASK 0x8
55 #define ORION_ACC_NEXT_EXT_BIT BIT(24)
56 #define ORION_ACC_NEXT_EXT_MASK 0x10
57 #define ORION_ACC_FIRST_EXT_BIT BIT(23)
58 #define ORION_ACC_FIRST_EXT_MASK 0x10
59 #define ORION_TURN_OFF_EXT_BIT BIT(22)
60 #define ORION_TURN_OFF_EXT_MASK 0x8
61 #define ORION_DEV_WIDTH_SHIFT 20
62 #define ORION_WR_HIGH_SHIFT 17
63 #define ORION_WR_HIGH_MASK 0x7
64 #define ORION_WR_LOW_SHIFT 14
65 #define ORION_WR_LOW_MASK 0x7
66 #define ORION_ALE_WR_SHIFT 11
67 #define ORION_ALE_WR_MASK 0x7
68 #define ORION_ACC_NEXT_SHIFT 7
69 #define ORION_ACC_NEXT_MASK 0xF
70 #define ORION_ACC_FIRST_SHIFT 3
71 #define ORION_ACC_FIRST_MASK 0xF
72 #define ORION_TURN_OFF_SHIFT 0
73 #define ORION_TURN_OFF_MASK 0x7
74
75 struct devbus_read_params {
76 u32 bus_width;
77 u32 badr_skew;
78 u32 turn_off;
79 u32 acc_first;
80 u32 acc_next;
81 u32 rd_setup;
82 u32 rd_hold;
83 };
84
85 struct devbus_write_params {
86 u32 sync_enable;
87 u32 wr_high;
88 u32 wr_low;
89 u32 ale_wr;
90 };
91
92 struct devbus {
93 struct device *dev;
94 void __iomem *base;
95 unsigned long tick_ps;
96 };
97
get_timing_param_ps(struct devbus * devbus,struct device_node * node,const char * name,u32 * ticks)98 static int get_timing_param_ps(struct devbus *devbus,
99 struct device_node *node,
100 const char *name,
101 u32 *ticks)
102 {
103 u32 time_ps;
104 int err;
105
106 err = of_property_read_u32(node, name, &time_ps);
107 if (err < 0) {
108 dev_err(devbus->dev, "%pOF has no '%s' property\n",
109 node, name);
110 return err;
111 }
112
113 *ticks = (time_ps + devbus->tick_ps - 1) / devbus->tick_ps;
114
115 dev_dbg(devbus->dev, "%s: %u ps -> 0x%x\n",
116 name, time_ps, *ticks);
117 return 0;
118 }
119
devbus_get_timing_params(struct devbus * devbus,struct device_node * node,struct devbus_read_params * r,struct devbus_write_params * w)120 static int devbus_get_timing_params(struct devbus *devbus,
121 struct device_node *node,
122 struct devbus_read_params *r,
123 struct devbus_write_params *w)
124 {
125 int err;
126
127 err = of_property_read_u32(node, "devbus,bus-width", &r->bus_width);
128 if (err < 0) {
129 dev_err(devbus->dev,
130 "%pOF has no 'devbus,bus-width' property\n",
131 node);
132 return err;
133 }
134
135 /*
136 * The bus width is encoded into the register as 0 for 8 bits,
137 * and 1 for 16 bits, so we do the necessary conversion here.
138 */
139 if (r->bus_width == 8)
140 r->bus_width = 0;
141 else if (r->bus_width == 16)
142 r->bus_width = 1;
143 else {
144 dev_err(devbus->dev, "invalid bus width %d\n", r->bus_width);
145 return -EINVAL;
146 }
147
148 err = get_timing_param_ps(devbus, node, "devbus,badr-skew-ps",
149 &r->badr_skew);
150 if (err < 0)
151 return err;
152
153 err = get_timing_param_ps(devbus, node, "devbus,turn-off-ps",
154 &r->turn_off);
155 if (err < 0)
156 return err;
157
158 err = get_timing_param_ps(devbus, node, "devbus,acc-first-ps",
159 &r->acc_first);
160 if (err < 0)
161 return err;
162
163 err = get_timing_param_ps(devbus, node, "devbus,acc-next-ps",
164 &r->acc_next);
165 if (err < 0)
166 return err;
167
168 if (of_device_is_compatible(devbus->dev->of_node, "marvell,mvebu-devbus")) {
169 err = get_timing_param_ps(devbus, node, "devbus,rd-setup-ps",
170 &r->rd_setup);
171 if (err < 0)
172 return err;
173
174 err = get_timing_param_ps(devbus, node, "devbus,rd-hold-ps",
175 &r->rd_hold);
176 if (err < 0)
177 return err;
178
179 err = of_property_read_u32(node, "devbus,sync-enable",
180 &w->sync_enable);
181 if (err < 0) {
182 dev_err(devbus->dev,
183 "%pOF has no 'devbus,sync-enable' property\n",
184 node);
185 return err;
186 }
187 }
188
189 err = get_timing_param_ps(devbus, node, "devbus,ale-wr-ps",
190 &w->ale_wr);
191 if (err < 0)
192 return err;
193
194 err = get_timing_param_ps(devbus, node, "devbus,wr-low-ps",
195 &w->wr_low);
196 if (err < 0)
197 return err;
198
199 err = get_timing_param_ps(devbus, node, "devbus,wr-high-ps",
200 &w->wr_high);
201 if (err < 0)
202 return err;
203
204 return 0;
205 }
206
devbus_orion_set_timing_params(struct devbus * devbus,struct device_node * node,struct devbus_read_params * r,struct devbus_write_params * w)207 static void devbus_orion_set_timing_params(struct devbus *devbus,
208 struct device_node *node,
209 struct devbus_read_params *r,
210 struct devbus_write_params *w)
211 {
212 u32 value;
213
214 /*
215 * The hardware designers found it would be a good idea to
216 * split most of the values in the register into two fields:
217 * one containing all the low-order bits, and another one
218 * containing just the high-order bit. For all of those
219 * fields, we have to split the value into these two parts.
220 */
221 value = (r->turn_off & ORION_TURN_OFF_MASK) << ORION_TURN_OFF_SHIFT |
222 (r->acc_first & ORION_ACC_FIRST_MASK) << ORION_ACC_FIRST_SHIFT |
223 (r->acc_next & ORION_ACC_NEXT_MASK) << ORION_ACC_NEXT_SHIFT |
224 (w->ale_wr & ORION_ALE_WR_MASK) << ORION_ALE_WR_SHIFT |
225 (w->wr_low & ORION_WR_LOW_MASK) << ORION_WR_LOW_SHIFT |
226 (w->wr_high & ORION_WR_HIGH_MASK) << ORION_WR_HIGH_SHIFT |
227 r->bus_width << ORION_DEV_WIDTH_SHIFT |
228 ((r->turn_off & ORION_TURN_OFF_EXT_MASK) ? ORION_TURN_OFF_EXT_BIT : 0) |
229 ((r->acc_first & ORION_ACC_FIRST_EXT_MASK) ? ORION_ACC_FIRST_EXT_BIT : 0) |
230 ((r->acc_next & ORION_ACC_NEXT_EXT_MASK) ? ORION_ACC_NEXT_EXT_BIT : 0) |
231 ((w->ale_wr & ORION_ALE_WR_EXT_MASK) ? ORION_ALE_WR_EXT_BIT : 0) |
232 ((w->wr_low & ORION_WR_LOW_EXT_MASK) ? ORION_WR_LOW_EXT_BIT : 0) |
233 ((w->wr_high & ORION_WR_HIGH_EXT_MASK) ? ORION_WR_HIGH_EXT_BIT : 0) |
234 (r->badr_skew << ORION_BADR_SKEW_SHIFT) |
235 ORION_RESERVED;
236
237 writel(value, devbus->base);
238 }
239
devbus_armada_set_timing_params(struct devbus * devbus,struct device_node * node,struct devbus_read_params * r,struct devbus_write_params * w)240 static void devbus_armada_set_timing_params(struct devbus *devbus,
241 struct device_node *node,
242 struct devbus_read_params *r,
243 struct devbus_write_params *w)
244 {
245 u32 value;
246
247 /* Set read timings */
248 value = r->bus_width << ARMADA_DEV_WIDTH_SHIFT |
249 r->badr_skew << ARMADA_BADR_SKEW_SHIFT |
250 r->rd_hold << ARMADA_RD_HOLD_SHIFT |
251 r->acc_next << ARMADA_ACC_NEXT_SHIFT |
252 r->rd_setup << ARMADA_RD_SETUP_SHIFT |
253 r->acc_first << ARMADA_ACC_FIRST_SHIFT |
254 r->turn_off;
255
256 dev_dbg(devbus->dev, "read parameters register 0x%p = 0x%x\n",
257 devbus->base + ARMADA_READ_PARAM_OFFSET,
258 value);
259
260 writel(value, devbus->base + ARMADA_READ_PARAM_OFFSET);
261
262 /* Set write timings */
263 value = w->sync_enable << ARMADA_SYNC_ENABLE_SHIFT |
264 w->wr_low << ARMADA_WR_LOW_SHIFT |
265 w->wr_high << ARMADA_WR_HIGH_SHIFT |
266 w->ale_wr;
267
268 dev_dbg(devbus->dev, "write parameters register: 0x%p = 0x%x\n",
269 devbus->base + ARMADA_WRITE_PARAM_OFFSET,
270 value);
271
272 writel(value, devbus->base + ARMADA_WRITE_PARAM_OFFSET);
273 }
274
mvebu_devbus_probe(struct platform_device * pdev)275 static int mvebu_devbus_probe(struct platform_device *pdev)
276 {
277 struct device *dev = &pdev->dev;
278 struct device_node *node = pdev->dev.of_node;
279 struct devbus_read_params r;
280 struct devbus_write_params w;
281 struct devbus *devbus;
282 struct resource *res;
283 struct clk *clk;
284 unsigned long rate;
285 int err;
286
287 devbus = devm_kzalloc(&pdev->dev, sizeof(struct devbus), GFP_KERNEL);
288 if (!devbus)
289 return -ENOMEM;
290
291 devbus->dev = dev;
292 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
293 devbus->base = devm_ioremap_resource(&pdev->dev, res);
294 if (IS_ERR(devbus->base))
295 return PTR_ERR(devbus->base);
296
297 clk = devm_clk_get(&pdev->dev, NULL);
298 if (IS_ERR(clk))
299 return PTR_ERR(clk);
300 clk_prepare_enable(clk);
301
302 /*
303 * Obtain clock period in picoseconds,
304 * we need this in order to convert timing
305 * parameters from cycles to picoseconds.
306 */
307 rate = clk_get_rate(clk) / 1000;
308 devbus->tick_ps = 1000000000 / rate;
309
310 dev_dbg(devbus->dev, "Setting timing parameter, tick is %lu ps\n",
311 devbus->tick_ps);
312
313 if (!of_property_read_bool(node, "devbus,keep-config")) {
314 /* Read the Device Tree node */
315 err = devbus_get_timing_params(devbus, node, &r, &w);
316 if (err < 0)
317 return err;
318
319 /* Set the new timing parameters */
320 if (of_device_is_compatible(node, "marvell,orion-devbus"))
321 devbus_orion_set_timing_params(devbus, node, &r, &w);
322 else
323 devbus_armada_set_timing_params(devbus, node, &r, &w);
324 }
325
326 /*
327 * We need to create a child device explicitly from here to
328 * guarantee that the child will be probed after the timing
329 * parameters for the bus are written.
330 */
331 err = of_platform_populate(node, NULL, NULL, dev);
332 if (err < 0)
333 return err;
334
335 return 0;
336 }
337
338 static const struct of_device_id mvebu_devbus_of_match[] = {
339 { .compatible = "marvell,mvebu-devbus" },
340 { .compatible = "marvell,orion-devbus" },
341 {},
342 };
343 MODULE_DEVICE_TABLE(of, mvebu_devbus_of_match);
344
345 static struct platform_driver mvebu_devbus_driver = {
346 .probe = mvebu_devbus_probe,
347 .driver = {
348 .name = "mvebu-devbus",
349 .of_match_table = mvebu_devbus_of_match,
350 },
351 };
352
mvebu_devbus_init(void)353 static int __init mvebu_devbus_init(void)
354 {
355 return platform_driver_register(&mvebu_devbus_driver);
356 }
357 module_init(mvebu_devbus_init);
358
359 MODULE_LICENSE("GPL v2");
360 MODULE_AUTHOR("Ezequiel Garcia <ezequiel.garcia@free-electrons.com>");
361 MODULE_DESCRIPTION("Marvell EBU SoC Device Bus controller");
362