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.h>
15 #include <linux/of_platform.h>
16 #include <linux/platform_device.h>
17 #include <linux/property.h>
18 #include <linux/mfd/syscon.h>
19 #include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
20 #include <linux/regmap.h>
21
22 struct imx_weim_devtype {
23 unsigned int cs_count;
24 unsigned int cs_regs_count;
25 unsigned int cs_stride;
26 unsigned int wcr_offset;
27 unsigned int wcr_bcm;
28 unsigned int wcr_cont_bclk;
29 };
30
31 static const struct imx_weim_devtype imx1_weim_devtype = {
32 .cs_count = 6,
33 .cs_regs_count = 2,
34 .cs_stride = 0x08,
35 };
36
37 static const struct imx_weim_devtype imx27_weim_devtype = {
38 .cs_count = 6,
39 .cs_regs_count = 3,
40 .cs_stride = 0x10,
41 };
42
43 static const struct imx_weim_devtype imx50_weim_devtype = {
44 .cs_count = 4,
45 .cs_regs_count = 6,
46 .cs_stride = 0x18,
47 .wcr_offset = 0x90,
48 .wcr_bcm = BIT(0),
49 .wcr_cont_bclk = BIT(3),
50 };
51
52 static const struct imx_weim_devtype imx51_weim_devtype = {
53 .cs_count = 6,
54 .cs_regs_count = 6,
55 .cs_stride = 0x18,
56 };
57
58 #define MAX_CS_REGS_COUNT 6
59 #define MAX_CS_COUNT 6
60 #define OF_REG_SIZE 3
61
62 struct cs_timing {
63 bool is_applied;
64 u32 regs[MAX_CS_REGS_COUNT];
65 };
66
67 struct cs_timing_state {
68 struct cs_timing cs[MAX_CS_COUNT];
69 };
70
71 struct weim_priv {
72 void __iomem *base;
73 struct cs_timing_state timing_state;
74 };
75
76 static const struct of_device_id weim_id_table[] = {
77 /* i.MX1/21 */
78 { .compatible = "fsl,imx1-weim", .data = &imx1_weim_devtype, },
79 /* i.MX25/27/31/35 */
80 { .compatible = "fsl,imx27-weim", .data = &imx27_weim_devtype, },
81 /* i.MX50/53/6Q */
82 { .compatible = "fsl,imx50-weim", .data = &imx50_weim_devtype, },
83 { .compatible = "fsl,imx6q-weim", .data = &imx50_weim_devtype, },
84 /* i.MX51 */
85 { .compatible = "fsl,imx51-weim", .data = &imx51_weim_devtype, },
86 { }
87 };
88 MODULE_DEVICE_TABLE(of, weim_id_table);
89
imx_weim_gpr_setup(struct platform_device * pdev)90 static int imx_weim_gpr_setup(struct platform_device *pdev)
91 {
92 struct device_node *np = pdev->dev.of_node;
93 struct of_range_parser parser;
94 struct of_range range;
95 struct regmap *gpr;
96 u32 gprvals[4] = {
97 05, /* CS0(128M) CS1(0M) CS2(0M) CS3(0M) */
98 033, /* CS0(64M) CS1(64M) CS2(0M) CS3(0M) */
99 0113, /* CS0(64M) CS1(32M) CS2(32M) CS3(0M) */
100 01111, /* CS0(32M) CS1(32M) CS2(32M) CS3(32M) */
101 };
102 u32 gprval = 0;
103 u32 val;
104 int cs = 0;
105 int i = 0;
106
107 gpr = syscon_regmap_lookup_by_phandle(np, "fsl,weim-cs-gpr");
108 if (IS_ERR(gpr)) {
109 dev_dbg(&pdev->dev, "failed to find weim-cs-gpr\n");
110 return 0;
111 }
112
113 if (of_range_parser_init(&parser, np))
114 goto err;
115
116 for_each_of_range(&parser, &range) {
117 cs = range.bus_addr >> 32;
118 val = (range.size / SZ_32M) | 1;
119 gprval |= val << cs * 3;
120 i++;
121 }
122
123 if (i == 0)
124 goto err;
125
126 for (i = 0; i < ARRAY_SIZE(gprvals); i++) {
127 if (gprval == gprvals[i]) {
128 /* Found it. Set up IOMUXC_GPR1[11:0] with it. */
129 regmap_update_bits(gpr, IOMUXC_GPR1, 0xfff, gprval);
130 return 0;
131 }
132 }
133
134 err:
135 dev_err(&pdev->dev, "Invalid 'ranges' configuration\n");
136 return -EINVAL;
137 }
138
139 /* Parse and set the timing for this device. */
weim_timing_setup(struct device * dev,struct device_node * np,const struct imx_weim_devtype * devtype)140 static int weim_timing_setup(struct device *dev, struct device_node *np,
141 const struct imx_weim_devtype *devtype)
142 {
143 u32 cs_idx, value[MAX_CS_REGS_COUNT];
144 int i, ret;
145 int reg_idx, num_regs;
146 struct cs_timing *cst;
147 struct weim_priv *priv;
148 struct cs_timing_state *ts;
149 void __iomem *base;
150
151 if (WARN_ON(devtype->cs_regs_count > MAX_CS_REGS_COUNT))
152 return -EINVAL;
153 if (WARN_ON(devtype->cs_count > MAX_CS_COUNT))
154 return -EINVAL;
155
156 priv = dev_get_drvdata(dev);
157 base = priv->base;
158 ts = &priv->timing_state;
159
160 ret = of_property_read_u32_array(np, "fsl,weim-cs-timing",
161 value, devtype->cs_regs_count);
162 if (ret)
163 return ret;
164
165 /*
166 * the child node's "reg" property may contain multiple address ranges,
167 * extract the chip select for each.
168 */
169 num_regs = of_property_count_elems_of_size(np, "reg", OF_REG_SIZE);
170 if (num_regs < 0)
171 return num_regs;
172 if (!num_regs)
173 return -EINVAL;
174 for (reg_idx = 0; reg_idx < num_regs; reg_idx++) {
175 /* get the CS index from this child node's "reg" property. */
176 ret = of_property_read_u32_index(np, "reg",
177 reg_idx * OF_REG_SIZE, &cs_idx);
178 if (ret)
179 break;
180
181 if (cs_idx >= devtype->cs_count)
182 return -EINVAL;
183
184 /* prevent re-configuring a CS that's already been configured */
185 cst = &ts->cs[cs_idx];
186 if (cst->is_applied && memcmp(value, cst->regs,
187 devtype->cs_regs_count * sizeof(u32))) {
188 dev_err(dev, "fsl,weim-cs-timing conflict on %pOF", np);
189 return -EINVAL;
190 }
191
192 /* set the timing for WEIM */
193 for (i = 0; i < devtype->cs_regs_count; i++)
194 writel(value[i],
195 base + cs_idx * devtype->cs_stride + i * 4);
196 if (!cst->is_applied) {
197 cst->is_applied = true;
198 memcpy(cst->regs, value,
199 devtype->cs_regs_count * sizeof(u32));
200 }
201 }
202
203 return 0;
204 }
205
weim_parse_dt(struct platform_device * pdev)206 static int weim_parse_dt(struct platform_device *pdev)
207 {
208 const struct imx_weim_devtype *devtype = device_get_match_data(&pdev->dev);
209 int ret = 0, have_child = 0;
210 struct device_node *child;
211 struct weim_priv *priv;
212 void __iomem *base;
213 u32 reg;
214
215 if (devtype == &imx50_weim_devtype) {
216 ret = imx_weim_gpr_setup(pdev);
217 if (ret)
218 return ret;
219 }
220
221 priv = dev_get_drvdata(&pdev->dev);
222 base = priv->base;
223
224 if (of_property_read_bool(pdev->dev.of_node, "fsl,burst-clk-enable")) {
225 if (devtype->wcr_bcm) {
226 reg = readl(base + devtype->wcr_offset);
227 reg |= devtype->wcr_bcm;
228
229 if (of_property_read_bool(pdev->dev.of_node,
230 "fsl,continuous-burst-clk")) {
231 if (devtype->wcr_cont_bclk) {
232 reg |= devtype->wcr_cont_bclk;
233 } else {
234 dev_err(&pdev->dev,
235 "continuous burst clk not supported.\n");
236 return -EINVAL;
237 }
238 }
239
240 writel(reg, base + devtype->wcr_offset);
241 } else {
242 dev_err(&pdev->dev, "burst clk mode not supported.\n");
243 return -EINVAL;
244 }
245 }
246
247 for_each_available_child_of_node(pdev->dev.of_node, child) {
248 ret = weim_timing_setup(&pdev->dev, child, devtype);
249 if (ret)
250 dev_warn(&pdev->dev, "%pOF set timing failed.\n",
251 child);
252 else
253 have_child = 1;
254 }
255
256 if (have_child)
257 ret = of_platform_default_populate(pdev->dev.of_node,
258 NULL, &pdev->dev);
259 if (ret)
260 dev_err(&pdev->dev, "%pOF fail to create devices.\n",
261 pdev->dev.of_node);
262 return ret;
263 }
264
weim_probe(struct platform_device * pdev)265 static int weim_probe(struct platform_device *pdev)
266 {
267 struct weim_priv *priv;
268 struct clk *clk;
269 void __iomem *base;
270 int ret;
271
272 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
273 if (!priv)
274 return -ENOMEM;
275
276 /* get the resource */
277 base = devm_platform_ioremap_resource(pdev, 0);
278 if (IS_ERR(base))
279 return PTR_ERR(base);
280
281 priv->base = base;
282 dev_set_drvdata(&pdev->dev, priv);
283
284 /* get the clock */
285 clk = devm_clk_get(&pdev->dev, NULL);
286 if (IS_ERR(clk))
287 return PTR_ERR(clk);
288
289 ret = clk_prepare_enable(clk);
290 if (ret)
291 return ret;
292
293 /* parse the device node */
294 ret = weim_parse_dt(pdev);
295 if (ret)
296 clk_disable_unprepare(clk);
297 else
298 dev_info(&pdev->dev, "Driver registered.\n");
299
300 return ret;
301 }
302
303 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
of_weim_notify(struct notifier_block * nb,unsigned long action,void * arg)304 static int of_weim_notify(struct notifier_block *nb, unsigned long action,
305 void *arg)
306 {
307 const struct imx_weim_devtype *devtype;
308 struct of_reconfig_data *rd = arg;
309 const struct of_device_id *of_id;
310 struct platform_device *pdev;
311 int ret = NOTIFY_OK;
312
313 switch (of_reconfig_get_state_change(action, rd)) {
314 case OF_RECONFIG_CHANGE_ADD:
315 of_id = of_match_node(weim_id_table, rd->dn->parent);
316 if (!of_id)
317 return NOTIFY_OK; /* not for us */
318
319 devtype = of_id->data;
320
321 pdev = of_find_device_by_node(rd->dn->parent);
322 if (!pdev) {
323 pr_err("%s: could not find platform device for '%pOF'\n",
324 __func__, rd->dn->parent);
325
326 return notifier_from_errno(-EINVAL);
327 }
328
329 if (weim_timing_setup(&pdev->dev, rd->dn, devtype))
330 dev_warn(&pdev->dev,
331 "Failed to setup timing for '%pOF'\n", rd->dn);
332
333 if (!of_node_check_flag(rd->dn, OF_POPULATED)) {
334 /*
335 * Clear the flag before adding the device so that
336 * fw_devlink doesn't skip adding consumers to this
337 * device.
338 */
339 rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
340 if (!of_platform_device_create(rd->dn, NULL, &pdev->dev)) {
341 dev_err(&pdev->dev,
342 "Failed to create child device '%pOF'\n",
343 rd->dn);
344 ret = notifier_from_errno(-EINVAL);
345 }
346 }
347
348 platform_device_put(pdev);
349
350 break;
351 case OF_RECONFIG_CHANGE_REMOVE:
352 if (!of_node_check_flag(rd->dn, OF_POPULATED))
353 return NOTIFY_OK; /* device already destroyed */
354
355 of_id = of_match_node(weim_id_table, rd->dn->parent);
356 if (!of_id)
357 return NOTIFY_OK; /* not for us */
358
359 pdev = of_find_device_by_node(rd->dn);
360 if (!pdev) {
361 pr_err("Could not find platform device for '%pOF'\n",
362 rd->dn);
363
364 ret = notifier_from_errno(-EINVAL);
365 } else {
366 of_platform_device_destroy(&pdev->dev, NULL);
367 platform_device_put(pdev);
368 }
369
370 break;
371 default:
372 break;
373 }
374
375 return ret;
376 }
377
378 static struct notifier_block weim_of_notifier = {
379 .notifier_call = of_weim_notify,
380 };
381 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
382
383 static struct platform_driver weim_driver = {
384 .driver = {
385 .name = "imx-weim",
386 .of_match_table = weim_id_table,
387 },
388 .probe = weim_probe,
389 };
390
weim_init(void)391 static int __init weim_init(void)
392 {
393 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
394 WARN_ON(of_reconfig_notifier_register(&weim_of_notifier));
395 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
396
397 return platform_driver_register(&weim_driver);
398 }
399 module_init(weim_init);
400
weim_exit(void)401 static void __exit weim_exit(void)
402 {
403 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
404 of_reconfig_notifier_unregister(&weim_of_notifier);
405 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
406
407 return platform_driver_unregister(&weim_driver);
408
409 }
410 module_exit(weim_exit);
411
412 MODULE_AUTHOR("Freescale Semiconductor Inc.");
413 MODULE_DESCRIPTION("i.MX EIM Controller Driver");
414 MODULE_LICENSE("GPL");
415