1 /*
2 * Memory controller driver for ARM PrimeCell PL172
3 * PrimeCell MultiPort Memory Controller (PL172)
4 *
5 * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
6 *
7 * Based on:
8 * TI AEMIF driver, Copyright (C) 2010 - 2013 Texas Instruments Inc.
9 *
10 * This file is licensed under the terms of the GNU General Public
11 * License version 2. This program is licensed "as is" without any
12 * warranty of any kind, whether express or implied.
13 */
14
15 #include <linux/amba/bus.h>
16 #include <linux/clk.h>
17 #include <linux/device.h>
18 #include <linux/err.h>
19 #include <linux/init.h>
20 #include <linux/io.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/of.h>
24 #include <linux/of_platform.h>
25 #include <linux/time.h>
26
27 #define MPMC_STATIC_CFG(n) (0x200 + 0x20 * n)
28 #define MPMC_STATIC_CFG_MW_8BIT 0x0
29 #define MPMC_STATIC_CFG_MW_16BIT 0x1
30 #define MPMC_STATIC_CFG_MW_32BIT 0x2
31 #define MPMC_STATIC_CFG_PM BIT(3)
32 #define MPMC_STATIC_CFG_PC BIT(6)
33 #define MPMC_STATIC_CFG_PB BIT(7)
34 #define MPMC_STATIC_CFG_EW BIT(8)
35 #define MPMC_STATIC_CFG_B BIT(19)
36 #define MPMC_STATIC_CFG_P BIT(20)
37 #define MPMC_STATIC_WAIT_WEN(n) (0x204 + 0x20 * n)
38 #define MPMC_STATIC_WAIT_WEN_MAX 0x0f
39 #define MPMC_STATIC_WAIT_OEN(n) (0x208 + 0x20 * n)
40 #define MPMC_STATIC_WAIT_OEN_MAX 0x0f
41 #define MPMC_STATIC_WAIT_RD(n) (0x20c + 0x20 * n)
42 #define MPMC_STATIC_WAIT_RD_MAX 0x1f
43 #define MPMC_STATIC_WAIT_PAGE(n) (0x210 + 0x20 * n)
44 #define MPMC_STATIC_WAIT_PAGE_MAX 0x1f
45 #define MPMC_STATIC_WAIT_WR(n) (0x214 + 0x20 * n)
46 #define MPMC_STATIC_WAIT_WR_MAX 0x1f
47 #define MPMC_STATIC_WAIT_TURN(n) (0x218 + 0x20 * n)
48 #define MPMC_STATIC_WAIT_TURN_MAX 0x0f
49
50 /* Maximum number of static chip selects */
51 #define PL172_MAX_CS 4
52
53 struct pl172_data {
54 void __iomem *base;
55 unsigned long rate;
56 struct clk *clk;
57 };
58
pl172_timing_prop(struct amba_device * adev,const struct device_node * np,const char * name,u32 reg_offset,u32 max,int start)59 static int pl172_timing_prop(struct amba_device *adev,
60 const struct device_node *np, const char *name,
61 u32 reg_offset, u32 max, int start)
62 {
63 struct pl172_data *pl172 = amba_get_drvdata(adev);
64 int cycles;
65 u32 val;
66
67 if (!of_property_read_u32(np, name, &val)) {
68 cycles = DIV_ROUND_UP(val * pl172->rate, NSEC_PER_MSEC) - start;
69 if (cycles < 0) {
70 cycles = 0;
71 } else if (cycles > max) {
72 dev_err(&adev->dev, "%s timing too tight\n", name);
73 return -EINVAL;
74 }
75
76 writel(cycles, pl172->base + reg_offset);
77 }
78
79 dev_dbg(&adev->dev, "%s: %u cycle(s)\n", name, start +
80 readl(pl172->base + reg_offset));
81
82 return 0;
83 }
84
pl172_setup_static(struct amba_device * adev,struct device_node * np,u32 cs)85 static int pl172_setup_static(struct amba_device *adev,
86 struct device_node *np, u32 cs)
87 {
88 struct pl172_data *pl172 = amba_get_drvdata(adev);
89 u32 cfg;
90 int ret;
91
92 /* MPMC static memory configuration */
93 if (!of_property_read_u32(np, "mpmc,memory-width", &cfg)) {
94 if (cfg == 8) {
95 cfg = MPMC_STATIC_CFG_MW_8BIT;
96 } else if (cfg == 16) {
97 cfg = MPMC_STATIC_CFG_MW_16BIT;
98 } else if (cfg == 32) {
99 cfg = MPMC_STATIC_CFG_MW_32BIT;
100 } else {
101 dev_err(&adev->dev, "invalid memory width cs%u\n", cs);
102 return -EINVAL;
103 }
104 } else {
105 dev_err(&adev->dev, "memory-width property required\n");
106 return -EINVAL;
107 }
108
109 if (of_property_read_bool(np, "mpmc,async-page-mode"))
110 cfg |= MPMC_STATIC_CFG_PM;
111
112 if (of_property_read_bool(np, "mpmc,cs-active-high"))
113 cfg |= MPMC_STATIC_CFG_PC;
114
115 if (of_property_read_bool(np, "mpmc,byte-lane-low"))
116 cfg |= MPMC_STATIC_CFG_PB;
117
118 if (of_property_read_bool(np, "mpmc,extended-wait"))
119 cfg |= MPMC_STATIC_CFG_EW;
120
121 if (amba_part(adev) == 0x172 &&
122 of_property_read_bool(np, "mpmc,buffer-enable"))
123 cfg |= MPMC_STATIC_CFG_B;
124
125 if (of_property_read_bool(np, "mpmc,write-protect"))
126 cfg |= MPMC_STATIC_CFG_P;
127
128 writel(cfg, pl172->base + MPMC_STATIC_CFG(cs));
129 dev_dbg(&adev->dev, "mpmc static config cs%u: 0x%08x\n", cs, cfg);
130
131 /* MPMC static memory timing */
132 ret = pl172_timing_prop(adev, np, "mpmc,write-enable-delay",
133 MPMC_STATIC_WAIT_WEN(cs),
134 MPMC_STATIC_WAIT_WEN_MAX, 1);
135 if (ret)
136 goto fail;
137
138 ret = pl172_timing_prop(adev, np, "mpmc,output-enable-delay",
139 MPMC_STATIC_WAIT_OEN(cs),
140 MPMC_STATIC_WAIT_OEN_MAX, 0);
141 if (ret)
142 goto fail;
143
144 ret = pl172_timing_prop(adev, np, "mpmc,read-access-delay",
145 MPMC_STATIC_WAIT_RD(cs),
146 MPMC_STATIC_WAIT_RD_MAX, 1);
147 if (ret)
148 goto fail;
149
150 ret = pl172_timing_prop(adev, np, "mpmc,page-mode-read-delay",
151 MPMC_STATIC_WAIT_PAGE(cs),
152 MPMC_STATIC_WAIT_PAGE_MAX, 1);
153 if (ret)
154 goto fail;
155
156 ret = pl172_timing_prop(adev, np, "mpmc,write-access-delay",
157 MPMC_STATIC_WAIT_WR(cs),
158 MPMC_STATIC_WAIT_WR_MAX, 2);
159 if (ret)
160 goto fail;
161
162 ret = pl172_timing_prop(adev, np, "mpmc,turn-round-delay",
163 MPMC_STATIC_WAIT_TURN(cs),
164 MPMC_STATIC_WAIT_TURN_MAX, 1);
165 if (ret)
166 goto fail;
167
168 return 0;
169 fail:
170 dev_err(&adev->dev, "failed to configure cs%u\n", cs);
171 return ret;
172 }
173
pl172_parse_cs_config(struct amba_device * adev,struct device_node * np)174 static int pl172_parse_cs_config(struct amba_device *adev,
175 struct device_node *np)
176 {
177 u32 cs;
178
179 if (!of_property_read_u32(np, "mpmc,cs", &cs)) {
180 if (cs >= PL172_MAX_CS) {
181 dev_err(&adev->dev, "cs%u invalid\n", cs);
182 return -EINVAL;
183 }
184
185 return pl172_setup_static(adev, np, cs);
186 }
187
188 dev_err(&adev->dev, "cs property required\n");
189
190 return -EINVAL;
191 }
192
193 static const char * const pl172_revisions[] = {"r1", "r2", "r2p3", "r2p4"};
194 static const char * const pl175_revisions[] = {"r1"};
195 static const char * const pl176_revisions[] = {"r0"};
196
pl172_probe(struct amba_device * adev,const struct amba_id * id)197 static int pl172_probe(struct amba_device *adev, const struct amba_id *id)
198 {
199 struct device_node *child_np, *np = adev->dev.of_node;
200 struct device *dev = &adev->dev;
201 static const char *rev = "?";
202 struct pl172_data *pl172;
203 int ret;
204
205 if (amba_part(adev) == 0x172) {
206 if (amba_rev(adev) < ARRAY_SIZE(pl172_revisions))
207 rev = pl172_revisions[amba_rev(adev)];
208 } else if (amba_part(adev) == 0x175) {
209 if (amba_rev(adev) < ARRAY_SIZE(pl175_revisions))
210 rev = pl175_revisions[amba_rev(adev)];
211 } else if (amba_part(adev) == 0x176) {
212 if (amba_rev(adev) < ARRAY_SIZE(pl176_revisions))
213 rev = pl176_revisions[amba_rev(adev)];
214 }
215
216 dev_info(dev, "ARM PL%x revision %s\n", amba_part(adev), rev);
217
218 pl172 = devm_kzalloc(dev, sizeof(*pl172), GFP_KERNEL);
219 if (!pl172)
220 return -ENOMEM;
221
222 pl172->clk = devm_clk_get(dev, "mpmcclk");
223 if (IS_ERR(pl172->clk)) {
224 dev_err(dev, "no mpmcclk provided clock\n");
225 return PTR_ERR(pl172->clk);
226 }
227
228 ret = clk_prepare_enable(pl172->clk);
229 if (ret) {
230 dev_err(dev, "unable to mpmcclk enable clock\n");
231 return ret;
232 }
233
234 pl172->rate = clk_get_rate(pl172->clk) / MSEC_PER_SEC;
235 if (!pl172->rate) {
236 dev_err(dev, "unable to get mpmcclk clock rate\n");
237 ret = -EINVAL;
238 goto err_clk_enable;
239 }
240
241 ret = amba_request_regions(adev, NULL);
242 if (ret) {
243 dev_err(dev, "unable to request AMBA regions\n");
244 goto err_clk_enable;
245 }
246
247 pl172->base = devm_ioremap(dev, adev->res.start,
248 resource_size(&adev->res));
249 if (!pl172->base) {
250 dev_err(dev, "ioremap failed\n");
251 ret = -ENOMEM;
252 goto err_no_ioremap;
253 }
254
255 amba_set_drvdata(adev, pl172);
256
257 /*
258 * Loop through each child node, which represent a chip select, and
259 * configure parameters and timing. If successful; populate devices
260 * under that node.
261 */
262 for_each_available_child_of_node(np, child_np) {
263 ret = pl172_parse_cs_config(adev, child_np);
264 if (ret)
265 continue;
266
267 of_platform_populate(child_np, NULL, NULL, dev);
268 }
269
270 return 0;
271
272 err_no_ioremap:
273 amba_release_regions(adev);
274 err_clk_enable:
275 clk_disable_unprepare(pl172->clk);
276 return ret;
277 }
278
pl172_remove(struct amba_device * adev)279 static int pl172_remove(struct amba_device *adev)
280 {
281 struct pl172_data *pl172 = amba_get_drvdata(adev);
282
283 clk_disable_unprepare(pl172->clk);
284 amba_release_regions(adev);
285
286 return 0;
287 }
288
289 static const struct amba_id pl172_ids[] = {
290 /* PrimeCell MPMC PL172, EMC found on NXP LPC18xx and LPC43xx */
291 {
292 .id = 0x07041172,
293 .mask = 0x3f0fffff,
294 },
295 /* PrimeCell MPMC PL175, EMC found on NXP LPC32xx */
296 {
297 .id = 0x07041175,
298 .mask = 0x3f0fffff,
299 },
300 /* PrimeCell MPMC PL176 */
301 {
302 .id = 0x89041176,
303 .mask = 0xff0fffff,
304 },
305 { 0, 0 },
306 };
307 MODULE_DEVICE_TABLE(amba, pl172_ids);
308
309 static struct amba_driver pl172_driver = {
310 .drv = {
311 .name = "memory-pl172",
312 },
313 .probe = pl172_probe,
314 .remove = pl172_remove,
315 .id_table = pl172_ids,
316 };
317 module_amba_driver(pl172_driver);
318
319 MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
320 MODULE_DESCRIPTION("PL172 Memory Controller Driver");
321 MODULE_LICENSE("GPL v2");
322
