1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Marvell EBU SoC Device Bus Controller
4 * (memory controller for NOR/NAND/SRAM/FPGA devices)
5 *
6 * Copyright (C) 2013-2014 Marvell
7 */
8
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/slab.h>
12 #include <linux/err.h>
13 #include <linux/io.h>
14 #include <linux/clk.h>
15 #include <linux/mbus.h>
16 #include <linux/of_platform.h>
17 #include <linux/of_address.h>
18 #include <linux/platform_device.h>
19
20 /* Register definitions */
21 #define ARMADA_DEV_WIDTH_SHIFT 30
22 #define ARMADA_BADR_SKEW_SHIFT 28
23 #define ARMADA_RD_HOLD_SHIFT 23
24 #define ARMADA_ACC_NEXT_SHIFT 17
25 #define ARMADA_RD_SETUP_SHIFT 12
26 #define ARMADA_ACC_FIRST_SHIFT 6
27
28 #define ARMADA_SYNC_ENABLE_SHIFT 24
29 #define ARMADA_WR_HIGH_SHIFT 16
30 #define ARMADA_WR_LOW_SHIFT 8
31
32 #define ARMADA_READ_PARAM_OFFSET 0x0
33 #define ARMADA_WRITE_PARAM_OFFSET 0x4
34
35 #define ORION_RESERVED (0x2 << 30)
36 #define ORION_BADR_SKEW_SHIFT 28
37 #define ORION_WR_HIGH_EXT_BIT BIT(27)
38 #define ORION_WR_HIGH_EXT_MASK 0x8
39 #define ORION_WR_LOW_EXT_BIT BIT(26)
40 #define ORION_WR_LOW_EXT_MASK 0x8
41 #define ORION_ALE_WR_EXT_BIT BIT(25)
42 #define ORION_ALE_WR_EXT_MASK 0x8
43 #define ORION_ACC_NEXT_EXT_BIT BIT(24)
44 #define ORION_ACC_NEXT_EXT_MASK 0x10
45 #define ORION_ACC_FIRST_EXT_BIT BIT(23)
46 #define ORION_ACC_FIRST_EXT_MASK 0x10
47 #define ORION_TURN_OFF_EXT_BIT BIT(22)
48 #define ORION_TURN_OFF_EXT_MASK 0x8
49 #define ORION_DEV_WIDTH_SHIFT 20
50 #define ORION_WR_HIGH_SHIFT 17
51 #define ORION_WR_HIGH_MASK 0x7
52 #define ORION_WR_LOW_SHIFT 14
53 #define ORION_WR_LOW_MASK 0x7
54 #define ORION_ALE_WR_SHIFT 11
55 #define ORION_ALE_WR_MASK 0x7
56 #define ORION_ACC_NEXT_SHIFT 7
57 #define ORION_ACC_NEXT_MASK 0xF
58 #define ORION_ACC_FIRST_SHIFT 3
59 #define ORION_ACC_FIRST_MASK 0xF
60 #define ORION_TURN_OFF_SHIFT 0
61 #define ORION_TURN_OFF_MASK 0x7
62
63 struct devbus_read_params {
64 u32 bus_width;
65 u32 badr_skew;
66 u32 turn_off;
67 u32 acc_first;
68 u32 acc_next;
69 u32 rd_setup;
70 u32 rd_hold;
71 };
72
73 struct devbus_write_params {
74 u32 sync_enable;
75 u32 wr_high;
76 u32 wr_low;
77 u32 ale_wr;
78 };
79
80 struct devbus {
81 struct device *dev;
82 void __iomem *base;
83 unsigned long tick_ps;
84 };
85
get_timing_param_ps(struct devbus * devbus,struct device_node * node,const char * name,u32 * ticks)86 static int get_timing_param_ps(struct devbus *devbus,
87 struct device_node *node,
88 const char *name,
89 u32 *ticks)
90 {
91 u32 time_ps;
92 int err;
93
94 err = of_property_read_u32(node, name, &time_ps);
95 if (err < 0) {
96 dev_err(devbus->dev, "%pOF has no '%s' property\n",
97 node, name);
98 return err;
99 }
100
101 *ticks = (time_ps + devbus->tick_ps - 1) / devbus->tick_ps;
102
103 dev_dbg(devbus->dev, "%s: %u ps -> 0x%x\n",
104 name, time_ps, *ticks);
105 return 0;
106 }
107
devbus_get_timing_params(struct devbus * devbus,struct device_node * node,struct devbus_read_params * r,struct devbus_write_params * w)108 static int devbus_get_timing_params(struct devbus *devbus,
109 struct device_node *node,
110 struct devbus_read_params *r,
111 struct devbus_write_params *w)
112 {
113 int err;
114
115 err = of_property_read_u32(node, "devbus,bus-width", &r->bus_width);
116 if (err < 0) {
117 dev_err(devbus->dev,
118 "%pOF has no 'devbus,bus-width' property\n",
119 node);
120 return err;
121 }
122
123 /*
124 * The bus width is encoded into the register as 0 for 8 bits,
125 * and 1 for 16 bits, so we do the necessary conversion here.
126 */
127 if (r->bus_width == 8) {
128 r->bus_width = 0;
129 } else if (r->bus_width == 16) {
130 r->bus_width = 1;
131 } else {
132 dev_err(devbus->dev, "invalid bus width %d\n", r->bus_width);
133 return -EINVAL;
134 }
135
136 err = get_timing_param_ps(devbus, node, "devbus,badr-skew-ps",
137 &r->badr_skew);
138 if (err < 0)
139 return err;
140
141 err = get_timing_param_ps(devbus, node, "devbus,turn-off-ps",
142 &r->turn_off);
143 if (err < 0)
144 return err;
145
146 err = get_timing_param_ps(devbus, node, "devbus,acc-first-ps",
147 &r->acc_first);
148 if (err < 0)
149 return err;
150
151 err = get_timing_param_ps(devbus, node, "devbus,acc-next-ps",
152 &r->acc_next);
153 if (err < 0)
154 return err;
155
156 if (of_device_is_compatible(devbus->dev->of_node, "marvell,mvebu-devbus")) {
157 err = get_timing_param_ps(devbus, node, "devbus,rd-setup-ps",
158 &r->rd_setup);
159 if (err < 0)
160 return err;
161
162 err = get_timing_param_ps(devbus, node, "devbus,rd-hold-ps",
163 &r->rd_hold);
164 if (err < 0)
165 return err;
166
167 err = of_property_read_u32(node, "devbus,sync-enable",
168 &w->sync_enable);
169 if (err < 0) {
170 dev_err(devbus->dev,
171 "%pOF has no 'devbus,sync-enable' property\n",
172 node);
173 return err;
174 }
175 }
176
177 err = get_timing_param_ps(devbus, node, "devbus,ale-wr-ps",
178 &w->ale_wr);
179 if (err < 0)
180 return err;
181
182 err = get_timing_param_ps(devbus, node, "devbus,wr-low-ps",
183 &w->wr_low);
184 if (err < 0)
185 return err;
186
187 err = get_timing_param_ps(devbus, node, "devbus,wr-high-ps",
188 &w->wr_high);
189 if (err < 0)
190 return err;
191
192 return 0;
193 }
194
devbus_orion_set_timing_params(struct devbus * devbus,struct device_node * node,struct devbus_read_params * r,struct devbus_write_params * w)195 static void devbus_orion_set_timing_params(struct devbus *devbus,
196 struct device_node *node,
197 struct devbus_read_params *r,
198 struct devbus_write_params *w)
199 {
200 u32 value;
201
202 /*
203 * The hardware designers found it would be a good idea to
204 * split most of the values in the register into two fields:
205 * one containing all the low-order bits, and another one
206 * containing just the high-order bit. For all of those
207 * fields, we have to split the value into these two parts.
208 */
209 value = (r->turn_off & ORION_TURN_OFF_MASK) << ORION_TURN_OFF_SHIFT |
210 (r->acc_first & ORION_ACC_FIRST_MASK) << ORION_ACC_FIRST_SHIFT |
211 (r->acc_next & ORION_ACC_NEXT_MASK) << ORION_ACC_NEXT_SHIFT |
212 (w->ale_wr & ORION_ALE_WR_MASK) << ORION_ALE_WR_SHIFT |
213 (w->wr_low & ORION_WR_LOW_MASK) << ORION_WR_LOW_SHIFT |
214 (w->wr_high & ORION_WR_HIGH_MASK) << ORION_WR_HIGH_SHIFT |
215 r->bus_width << ORION_DEV_WIDTH_SHIFT |
216 ((r->turn_off & ORION_TURN_OFF_EXT_MASK) ? ORION_TURN_OFF_EXT_BIT : 0) |
217 ((r->acc_first & ORION_ACC_FIRST_EXT_MASK) ? ORION_ACC_FIRST_EXT_BIT : 0) |
218 ((r->acc_next & ORION_ACC_NEXT_EXT_MASK) ? ORION_ACC_NEXT_EXT_BIT : 0) |
219 ((w->ale_wr & ORION_ALE_WR_EXT_MASK) ? ORION_ALE_WR_EXT_BIT : 0) |
220 ((w->wr_low & ORION_WR_LOW_EXT_MASK) ? ORION_WR_LOW_EXT_BIT : 0) |
221 ((w->wr_high & ORION_WR_HIGH_EXT_MASK) ? ORION_WR_HIGH_EXT_BIT : 0) |
222 (r->badr_skew << ORION_BADR_SKEW_SHIFT) |
223 ORION_RESERVED;
224
225 writel(value, devbus->base);
226 }
227
devbus_armada_set_timing_params(struct devbus * devbus,struct device_node * node,struct devbus_read_params * r,struct devbus_write_params * w)228 static void devbus_armada_set_timing_params(struct devbus *devbus,
229 struct device_node *node,
230 struct devbus_read_params *r,
231 struct devbus_write_params *w)
232 {
233 u32 value;
234
235 /* Set read timings */
236 value = r->bus_width << ARMADA_DEV_WIDTH_SHIFT |
237 r->badr_skew << ARMADA_BADR_SKEW_SHIFT |
238 r->rd_hold << ARMADA_RD_HOLD_SHIFT |
239 r->acc_next << ARMADA_ACC_NEXT_SHIFT |
240 r->rd_setup << ARMADA_RD_SETUP_SHIFT |
241 r->acc_first << ARMADA_ACC_FIRST_SHIFT |
242 r->turn_off;
243
244 dev_dbg(devbus->dev, "read parameters register 0x%p = 0x%x\n",
245 devbus->base + ARMADA_READ_PARAM_OFFSET,
246 value);
247
248 writel(value, devbus->base + ARMADA_READ_PARAM_OFFSET);
249
250 /* Set write timings */
251 value = w->sync_enable << ARMADA_SYNC_ENABLE_SHIFT |
252 w->wr_low << ARMADA_WR_LOW_SHIFT |
253 w->wr_high << ARMADA_WR_HIGH_SHIFT |
254 w->ale_wr;
255
256 dev_dbg(devbus->dev, "write parameters register: 0x%p = 0x%x\n",
257 devbus->base + ARMADA_WRITE_PARAM_OFFSET,
258 value);
259
260 writel(value, devbus->base + ARMADA_WRITE_PARAM_OFFSET);
261 }
262
mvebu_devbus_probe(struct platform_device * pdev)263 static int mvebu_devbus_probe(struct platform_device *pdev)
264 {
265 struct device *dev = &pdev->dev;
266 struct device_node *node = pdev->dev.of_node;
267 struct devbus_read_params r;
268 struct devbus_write_params w;
269 struct devbus *devbus;
270 struct clk *clk;
271 unsigned long rate;
272 int err;
273
274 devbus = devm_kzalloc(&pdev->dev, sizeof(struct devbus), GFP_KERNEL);
275 if (!devbus)
276 return -ENOMEM;
277
278 devbus->dev = dev;
279 devbus->base = devm_platform_ioremap_resource(pdev, 0);
280 if (IS_ERR(devbus->base))
281 return PTR_ERR(devbus->base);
282
283 clk = devm_clk_get_enabled(&pdev->dev, NULL);
284 if (IS_ERR(clk))
285 return PTR_ERR(clk);
286
287 /*
288 * Obtain clock period in picoseconds,
289 * we need this in order to convert timing
290 * parameters from cycles to picoseconds.
291 */
292 rate = clk_get_rate(clk) / 1000;
293 devbus->tick_ps = 1000000000 / rate;
294
295 dev_dbg(devbus->dev, "Setting timing parameter, tick is %lu ps\n",
296 devbus->tick_ps);
297
298 if (!of_property_read_bool(node, "devbus,keep-config")) {
299 /* Read the Device Tree node */
300 err = devbus_get_timing_params(devbus, node, &r, &w);
301 if (err < 0)
302 return err;
303
304 /* Set the new timing parameters */
305 if (of_device_is_compatible(node, "marvell,orion-devbus"))
306 devbus_orion_set_timing_params(devbus, node, &r, &w);
307 else
308 devbus_armada_set_timing_params(devbus, node, &r, &w);
309 }
310
311 /*
312 * We need to create a child device explicitly from here to
313 * guarantee that the child will be probed after the timing
314 * parameters for the bus are written.
315 */
316 err = of_platform_populate(node, NULL, NULL, dev);
317 if (err < 0)
318 return err;
319
320 return 0;
321 }
322
323 static const struct of_device_id mvebu_devbus_of_match[] = {
324 { .compatible = "marvell,mvebu-devbus" },
325 { .compatible = "marvell,orion-devbus" },
326 {},
327 };
328 MODULE_DEVICE_TABLE(of, mvebu_devbus_of_match);
329
330 static struct platform_driver mvebu_devbus_driver = {
331 .probe = mvebu_devbus_probe,
332 .driver = {
333 .name = "mvebu-devbus",
334 .of_match_table = mvebu_devbus_of_match,
335 },
336 };
337
mvebu_devbus_init(void)338 static int __init mvebu_devbus_init(void)
339 {
340 return platform_driver_register(&mvebu_devbus_driver);
341 }
342 module_init(mvebu_devbus_init);
343
344 MODULE_AUTHOR("Ezequiel Garcia <ezequiel.garcia@free-electrons.com>");
345 MODULE_DESCRIPTION("Marvell EBU SoC Device Bus controller");
346