1 /*
2 * EIM driver for Freescale's i.MX chips
3 *
4 * Copyright (C) 2013 Freescale Semiconductor, Inc.
5 *
6 * This file is licensed under the terms of the GNU General Public
7 * License version 2. This program is licensed "as is" without any
8 * warranty of any kind, whether express or implied.
9 */
10 #include <linux/module.h>
11 #include <linux/clk.h>
12 #include <linux/io.h>
13 #include <linux/of_address.h>
14 #include <linux/of_device.h>
15 #include <linux/mfd/syscon.h>
16 #include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
17 #include <linux/regmap.h>
18
19 struct imx_weim_devtype {
20 unsigned int cs_count;
21 unsigned int cs_regs_count;
22 unsigned int cs_stride;
23 unsigned int wcr_offset;
24 unsigned int wcr_bcm;
25 unsigned int wcr_cont_bclk;
26 };
27
28 static const struct imx_weim_devtype imx1_weim_devtype = {
29 .cs_count = 6,
30 .cs_regs_count = 2,
31 .cs_stride = 0x08,
32 };
33
34 static const struct imx_weim_devtype imx27_weim_devtype = {
35 .cs_count = 6,
36 .cs_regs_count = 3,
37 .cs_stride = 0x10,
38 };
39
40 static const struct imx_weim_devtype imx50_weim_devtype = {
41 .cs_count = 4,
42 .cs_regs_count = 6,
43 .cs_stride = 0x18,
44 .wcr_offset = 0x90,
45 .wcr_bcm = BIT(0),
46 .wcr_cont_bclk = BIT(3),
47 };
48
49 static const struct imx_weim_devtype imx51_weim_devtype = {
50 .cs_count = 6,
51 .cs_regs_count = 6,
52 .cs_stride = 0x18,
53 };
54
55 #define MAX_CS_REGS_COUNT 6
56 #define MAX_CS_COUNT 6
57 #define OF_REG_SIZE 3
58
59 struct cs_timing {
60 bool is_applied;
61 u32 regs[MAX_CS_REGS_COUNT];
62 };
63
64 struct cs_timing_state {
65 struct cs_timing cs[MAX_CS_COUNT];
66 };
67
68 struct weim_priv {
69 void __iomem *base;
70 struct cs_timing_state timing_state;
71 };
72
73 static const struct of_device_id weim_id_table[] = {
74 /* i.MX1/21 */
75 { .compatible = "fsl,imx1-weim", .data = &imx1_weim_devtype, },
76 /* i.MX25/27/31/35 */
77 { .compatible = "fsl,imx27-weim", .data = &imx27_weim_devtype, },
78 /* i.MX50/53/6Q */
79 { .compatible = "fsl,imx50-weim", .data = &imx50_weim_devtype, },
80 { .compatible = "fsl,imx6q-weim", .data = &imx50_weim_devtype, },
81 /* i.MX51 */
82 { .compatible = "fsl,imx51-weim", .data = &imx51_weim_devtype, },
83 { }
84 };
85 MODULE_DEVICE_TABLE(of, weim_id_table);
86
imx_weim_gpr_setup(struct platform_device * pdev)87 static int imx_weim_gpr_setup(struct platform_device *pdev)
88 {
89 struct device_node *np = pdev->dev.of_node;
90 struct of_range_parser parser;
91 struct of_range range;
92 struct regmap *gpr;
93 u32 gprvals[4] = {
94 05, /* CS0(128M) CS1(0M) CS2(0M) CS3(0M) */
95 033, /* CS0(64M) CS1(64M) CS2(0M) CS3(0M) */
96 0113, /* CS0(64M) CS1(32M) CS2(32M) CS3(0M) */
97 01111, /* CS0(32M) CS1(32M) CS2(32M) CS3(32M) */
98 };
99 u32 gprval = 0;
100 u32 val;
101 int cs = 0;
102 int i = 0;
103
104 gpr = syscon_regmap_lookup_by_phandle(np, "fsl,weim-cs-gpr");
105 if (IS_ERR(gpr)) {
106 dev_dbg(&pdev->dev, "failed to find weim-cs-gpr\n");
107 return 0;
108 }
109
110 if (of_range_parser_init(&parser, np))
111 goto err;
112
113 for_each_of_range(&parser, &range) {
114 cs = range.bus_addr >> 32;
115 val = (range.size / SZ_32M) | 1;
116 gprval |= val << cs * 3;
117 i++;
118 }
119
120 if (i == 0)
121 goto err;
122
123 for (i = 0; i < ARRAY_SIZE(gprvals); i++) {
124 if (gprval == gprvals[i]) {
125 /* Found it. Set up IOMUXC_GPR1[11:0] with it. */
126 regmap_update_bits(gpr, IOMUXC_GPR1, 0xfff, gprval);
127 return 0;
128 }
129 }
130
131 err:
132 dev_err(&pdev->dev, "Invalid 'ranges' configuration\n");
133 return -EINVAL;
134 }
135
136 /* Parse and set the timing for this device. */
weim_timing_setup(struct device * dev,struct device_node * np,const struct imx_weim_devtype * devtype)137 static int weim_timing_setup(struct device *dev, struct device_node *np,
138 const struct imx_weim_devtype *devtype)
139 {
140 u32 cs_idx, value[MAX_CS_REGS_COUNT];
141 int i, ret;
142 int reg_idx, num_regs;
143 struct cs_timing *cst;
144 struct weim_priv *priv;
145 struct cs_timing_state *ts;
146 void __iomem *base;
147
148 if (WARN_ON(devtype->cs_regs_count > MAX_CS_REGS_COUNT))
149 return -EINVAL;
150 if (WARN_ON(devtype->cs_count > MAX_CS_COUNT))
151 return -EINVAL;
152
153 priv = dev_get_drvdata(dev);
154 base = priv->base;
155 ts = &priv->timing_state;
156
157 ret = of_property_read_u32_array(np, "fsl,weim-cs-timing",
158 value, devtype->cs_regs_count);
159 if (ret)
160 return ret;
161
162 /*
163 * the child node's "reg" property may contain multiple address ranges,
164 * extract the chip select for each.
165 */
166 num_regs = of_property_count_elems_of_size(np, "reg", OF_REG_SIZE);
167 if (num_regs < 0)
168 return num_regs;
169 if (!num_regs)
170 return -EINVAL;
171 for (reg_idx = 0; reg_idx < num_regs; reg_idx++) {
172 /* get the CS index from this child node's "reg" property. */
173 ret = of_property_read_u32_index(np, "reg",
174 reg_idx * OF_REG_SIZE, &cs_idx);
175 if (ret)
176 break;
177
178 if (cs_idx >= devtype->cs_count)
179 return -EINVAL;
180
181 /* prevent re-configuring a CS that's already been configured */
182 cst = &ts->cs[cs_idx];
183 if (cst->is_applied && memcmp(value, cst->regs,
184 devtype->cs_regs_count * sizeof(u32))) {
185 dev_err(dev, "fsl,weim-cs-timing conflict on %pOF", np);
186 return -EINVAL;
187 }
188
189 /* set the timing for WEIM */
190 for (i = 0; i < devtype->cs_regs_count; i++)
191 writel(value[i],
192 base + cs_idx * devtype->cs_stride + i * 4);
193 if (!cst->is_applied) {
194 cst->is_applied = true;
195 memcpy(cst->regs, value,
196 devtype->cs_regs_count * sizeof(u32));
197 }
198 }
199
200 return 0;
201 }
202
weim_parse_dt(struct platform_device * pdev)203 static int weim_parse_dt(struct platform_device *pdev)
204 {
205 const struct of_device_id *of_id = of_match_device(weim_id_table,
206 &pdev->dev);
207 const struct imx_weim_devtype *devtype = of_id->data;
208 int ret = 0, have_child = 0;
209 struct device_node *child;
210 struct weim_priv *priv;
211 void __iomem *base;
212 u32 reg;
213
214 if (devtype == &imx50_weim_devtype) {
215 ret = imx_weim_gpr_setup(pdev);
216 if (ret)
217 return ret;
218 }
219
220 priv = dev_get_drvdata(&pdev->dev);
221 base = priv->base;
222
223 if (of_property_read_bool(pdev->dev.of_node, "fsl,burst-clk-enable")) {
224 if (devtype->wcr_bcm) {
225 reg = readl(base + devtype->wcr_offset);
226 reg |= devtype->wcr_bcm;
227
228 if (of_property_read_bool(pdev->dev.of_node,
229 "fsl,continuous-burst-clk")) {
230 if (devtype->wcr_cont_bclk) {
231 reg |= devtype->wcr_cont_bclk;
232 } else {
233 dev_err(&pdev->dev,
234 "continuous burst clk not supported.\n");
235 return -EINVAL;
236 }
237 }
238
239 writel(reg, base + devtype->wcr_offset);
240 } else {
241 dev_err(&pdev->dev, "burst clk mode not supported.\n");
242 return -EINVAL;
243 }
244 }
245
246 for_each_available_child_of_node(pdev->dev.of_node, child) {
247 ret = weim_timing_setup(&pdev->dev, child, devtype);
248 if (ret)
249 dev_warn(&pdev->dev, "%pOF set timing failed.\n",
250 child);
251 else
252 have_child = 1;
253 }
254
255 if (have_child)
256 ret = of_platform_default_populate(pdev->dev.of_node,
257 NULL, &pdev->dev);
258 if (ret)
259 dev_err(&pdev->dev, "%pOF fail to create devices.\n",
260 pdev->dev.of_node);
261 return ret;
262 }
263
weim_probe(struct platform_device * pdev)264 static int weim_probe(struct platform_device *pdev)
265 {
266 struct weim_priv *priv;
267 struct clk *clk;
268 void __iomem *base;
269 int ret;
270
271 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
272 if (!priv)
273 return -ENOMEM;
274
275 /* get the resource */
276 base = devm_platform_ioremap_resource(pdev, 0);
277 if (IS_ERR(base))
278 return PTR_ERR(base);
279
280 priv->base = base;
281 dev_set_drvdata(&pdev->dev, priv);
282
283 /* get the clock */
284 clk = devm_clk_get(&pdev->dev, NULL);
285 if (IS_ERR(clk))
286 return PTR_ERR(clk);
287
288 ret = clk_prepare_enable(clk);
289 if (ret)
290 return ret;
291
292 /* parse the device node */
293 ret = weim_parse_dt(pdev);
294 if (ret)
295 clk_disable_unprepare(clk);
296 else
297 dev_info(&pdev->dev, "Driver registered.\n");
298
299 return ret;
300 }
301
302 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
of_weim_notify(struct notifier_block * nb,unsigned long action,void * arg)303 static int of_weim_notify(struct notifier_block *nb, unsigned long action,
304 void *arg)
305 {
306 const struct imx_weim_devtype *devtype;
307 struct of_reconfig_data *rd = arg;
308 const struct of_device_id *of_id;
309 struct platform_device *pdev;
310 int ret = NOTIFY_OK;
311
312 switch (of_reconfig_get_state_change(action, rd)) {
313 case OF_RECONFIG_CHANGE_ADD:
314 of_id = of_match_node(weim_id_table, rd->dn->parent);
315 if (!of_id)
316 return NOTIFY_OK; /* not for us */
317
318 devtype = of_id->data;
319
320 pdev = of_find_device_by_node(rd->dn->parent);
321 if (!pdev) {
322 pr_err("%s: could not find platform device for '%pOF'\n",
323 __func__, rd->dn->parent);
324
325 return notifier_from_errno(-EINVAL);
326 }
327
328 if (weim_timing_setup(&pdev->dev, rd->dn, devtype))
329 dev_warn(&pdev->dev,
330 "Failed to setup timing for '%pOF'\n", rd->dn);
331
332 if (!of_node_check_flag(rd->dn, OF_POPULATED)) {
333 /*
334 * Clear the flag before adding the device so that
335 * fw_devlink doesn't skip adding consumers to this
336 * device.
337 */
338 rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
339 if (!of_platform_device_create(rd->dn, NULL, &pdev->dev)) {
340 dev_err(&pdev->dev,
341 "Failed to create child device '%pOF'\n",
342 rd->dn);
343 ret = notifier_from_errno(-EINVAL);
344 }
345 }
346
347 platform_device_put(pdev);
348
349 break;
350 case OF_RECONFIG_CHANGE_REMOVE:
351 if (!of_node_check_flag(rd->dn, OF_POPULATED))
352 return NOTIFY_OK; /* device already destroyed */
353
354 of_id = of_match_node(weim_id_table, rd->dn->parent);
355 if (!of_id)
356 return NOTIFY_OK; /* not for us */
357
358 pdev = of_find_device_by_node(rd->dn);
359 if (!pdev) {
360 pr_err("Could not find platform device for '%pOF'\n",
361 rd->dn);
362
363 ret = notifier_from_errno(-EINVAL);
364 } else {
365 of_platform_device_destroy(&pdev->dev, NULL);
366 platform_device_put(pdev);
367 }
368
369 break;
370 default:
371 break;
372 }
373
374 return ret;
375 }
376
377 static struct notifier_block weim_of_notifier = {
378 .notifier_call = of_weim_notify,
379 };
380 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
381
382 static struct platform_driver weim_driver = {
383 .driver = {
384 .name = "imx-weim",
385 .of_match_table = weim_id_table,
386 },
387 .probe = weim_probe,
388 };
389
weim_init(void)390 static int __init weim_init(void)
391 {
392 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
393 WARN_ON(of_reconfig_notifier_register(&weim_of_notifier));
394 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
395
396 return platform_driver_register(&weim_driver);
397 }
398 module_init(weim_init);
399
weim_exit(void)400 static void __exit weim_exit(void)
401 {
402 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
403 of_reconfig_notifier_unregister(&weim_of_notifier);
404 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
405
406 return platform_driver_unregister(&weim_driver);
407
408 }
409 module_exit(weim_exit);
410
411 MODULE_AUTHOR("Freescale Semiconductor Inc.");
412 MODULE_DESCRIPTION("i.MX EIM Controller Driver");
413 MODULE_LICENSE("GPL");
414