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_device.h>
14 #include <linux/mfd/syscon.h>
15 #include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
16 #include <linux/regmap.h>
17
18 struct imx_weim_devtype {
19 unsigned int cs_count;
20 unsigned int cs_regs_count;
21 unsigned int cs_stride;
22 unsigned int wcr_offset;
23 unsigned int wcr_bcm;
24 unsigned int wcr_cont_bclk;
25 };
26
27 static const struct imx_weim_devtype imx1_weim_devtype = {
28 .cs_count = 6,
29 .cs_regs_count = 2,
30 .cs_stride = 0x08,
31 };
32
33 static const struct imx_weim_devtype imx27_weim_devtype = {
34 .cs_count = 6,
35 .cs_regs_count = 3,
36 .cs_stride = 0x10,
37 };
38
39 static const struct imx_weim_devtype imx50_weim_devtype = {
40 .cs_count = 4,
41 .cs_regs_count = 6,
42 .cs_stride = 0x18,
43 .wcr_offset = 0x90,
44 .wcr_bcm = BIT(0),
45 .wcr_cont_bclk = BIT(3),
46 };
47
48 static const struct imx_weim_devtype imx51_weim_devtype = {
49 .cs_count = 6,
50 .cs_regs_count = 6,
51 .cs_stride = 0x18,
52 };
53
54 #define MAX_CS_REGS_COUNT 6
55 #define MAX_CS_COUNT 6
56 #define OF_REG_SIZE 3
57
58 struct cs_timing {
59 bool is_applied;
60 u32 regs[MAX_CS_REGS_COUNT];
61 };
62
63 struct cs_timing_state {
64 struct cs_timing cs[MAX_CS_COUNT];
65 };
66
67 struct weim_priv {
68 void __iomem *base;
69 struct cs_timing_state timing_state;
70 };
71
72 static const struct of_device_id weim_id_table[] = {
73 /* i.MX1/21 */
74 { .compatible = "fsl,imx1-weim", .data = &imx1_weim_devtype, },
75 /* i.MX25/27/31/35 */
76 { .compatible = "fsl,imx27-weim", .data = &imx27_weim_devtype, },
77 /* i.MX50/53/6Q */
78 { .compatible = "fsl,imx50-weim", .data = &imx50_weim_devtype, },
79 { .compatible = "fsl,imx6q-weim", .data = &imx50_weim_devtype, },
80 /* i.MX51 */
81 { .compatible = "fsl,imx51-weim", .data = &imx51_weim_devtype, },
82 { }
83 };
84 MODULE_DEVICE_TABLE(of, weim_id_table);
85
imx_weim_gpr_setup(struct platform_device * pdev)86 static int imx_weim_gpr_setup(struct platform_device *pdev)
87 {
88 struct device_node *np = pdev->dev.of_node;
89 struct property *prop;
90 const __be32 *p;
91 struct regmap *gpr;
92 u32 gprvals[4] = {
93 05, /* CS0(128M) CS1(0M) CS2(0M) CS3(0M) */
94 033, /* CS0(64M) CS1(64M) CS2(0M) CS3(0M) */
95 0113, /* CS0(64M) CS1(32M) CS2(32M) CS3(0M) */
96 01111, /* CS0(32M) CS1(32M) CS2(32M) CS3(32M) */
97 };
98 u32 gprval = 0;
99 u32 val;
100 int cs = 0;
101 int i = 0;
102
103 gpr = syscon_regmap_lookup_by_phandle(np, "fsl,weim-cs-gpr");
104 if (IS_ERR(gpr)) {
105 dev_dbg(&pdev->dev, "failed to find weim-cs-gpr\n");
106 return 0;
107 }
108
109 of_property_for_each_u32(np, "ranges", prop, p, val) {
110 if (i % 4 == 0) {
111 cs = val;
112 } else if (i % 4 == 3 && val) {
113 val = (val / SZ_32M) | 1;
114 gprval |= val << cs * 3;
115 }
116 i++;
117 }
118
119 if (i == 0 || i % 4)
120 goto err;
121
122 for (i = 0; i < ARRAY_SIZE(gprvals); i++) {
123 if (gprval == gprvals[i]) {
124 /* Found it. Set up IOMUXC_GPR1[11:0] with it. */
125 regmap_update_bits(gpr, IOMUXC_GPR1, 0xfff, gprval);
126 return 0;
127 }
128 }
129
130 err:
131 dev_err(&pdev->dev, "Invalid 'ranges' configuration\n");
132 return -EINVAL;
133 }
134
135 /* Parse and set the timing for this device. */
weim_timing_setup(struct device * dev,struct device_node * np,const struct imx_weim_devtype * devtype)136 static int weim_timing_setup(struct device *dev, struct device_node *np,
137 const struct imx_weim_devtype *devtype)
138 {
139 u32 cs_idx, value[MAX_CS_REGS_COUNT];
140 int i, ret;
141 int reg_idx, num_regs;
142 struct cs_timing *cst;
143 struct weim_priv *priv;
144 struct cs_timing_state *ts;
145 void __iomem *base;
146
147 if (WARN_ON(devtype->cs_regs_count > MAX_CS_REGS_COUNT))
148 return -EINVAL;
149 if (WARN_ON(devtype->cs_count > MAX_CS_COUNT))
150 return -EINVAL;
151
152 priv = dev_get_drvdata(dev);
153 base = priv->base;
154 ts = &priv->timing_state;
155
156 ret = of_property_read_u32_array(np, "fsl,weim-cs-timing",
157 value, devtype->cs_regs_count);
158 if (ret)
159 return ret;
160
161 /*
162 * the child node's "reg" property may contain multiple address ranges,
163 * extract the chip select for each.
164 */
165 num_regs = of_property_count_elems_of_size(np, "reg", OF_REG_SIZE);
166 if (num_regs < 0)
167 return num_regs;
168 if (!num_regs)
169 return -EINVAL;
170 for (reg_idx = 0; reg_idx < num_regs; reg_idx++) {
171 /* get the CS index from this child node's "reg" property. */
172 ret = of_property_read_u32_index(np, "reg",
173 reg_idx * OF_REG_SIZE, &cs_idx);
174 if (ret)
175 break;
176
177 if (cs_idx >= devtype->cs_count)
178 return -EINVAL;
179
180 /* prevent re-configuring a CS that's already been configured */
181 cst = &ts->cs[cs_idx];
182 if (cst->is_applied && memcmp(value, cst->regs,
183 devtype->cs_regs_count * sizeof(u32))) {
184 dev_err(dev, "fsl,weim-cs-timing conflict on %pOF", np);
185 return -EINVAL;
186 }
187
188 /* set the timing for WEIM */
189 for (i = 0; i < devtype->cs_regs_count; i++)
190 writel(value[i],
191 base + cs_idx * devtype->cs_stride + i * 4);
192 if (!cst->is_applied) {
193 cst->is_applied = true;
194 memcpy(cst->regs, value,
195 devtype->cs_regs_count * sizeof(u32));
196 }
197 }
198
199 return 0;
200 }
201
weim_parse_dt(struct platform_device * pdev)202 static int weim_parse_dt(struct platform_device *pdev)
203 {
204 const struct of_device_id *of_id = of_match_device(weim_id_table,
205 &pdev->dev);
206 const struct imx_weim_devtype *devtype = of_id->data;
207 struct device_node *child;
208 int ret, have_child = 0;
209 struct weim_priv *priv;
210 void __iomem *base;
211 u32 reg;
212
213 if (devtype == &imx50_weim_devtype) {
214 ret = imx_weim_gpr_setup(pdev);
215 if (ret)
216 return ret;
217 }
218
219 priv = dev_get_drvdata(&pdev->dev);
220 base = priv->base;
221
222 if (of_property_read_bool(pdev->dev.of_node, "fsl,burst-clk-enable")) {
223 if (devtype->wcr_bcm) {
224 reg = readl(base + devtype->wcr_offset);
225 reg |= devtype->wcr_bcm;
226
227 if (of_property_read_bool(pdev->dev.of_node,
228 "fsl,continuous-burst-clk")) {
229 if (devtype->wcr_cont_bclk) {
230 reg |= devtype->wcr_cont_bclk;
231 } else {
232 dev_err(&pdev->dev,
233 "continuous burst clk not supported.\n");
234 return -EINVAL;
235 }
236 }
237
238 writel(reg, base + devtype->wcr_offset);
239 } else {
240 dev_err(&pdev->dev, "burst clk mode not supported.\n");
241 return -EINVAL;
242 }
243 }
244
245 for_each_available_child_of_node(pdev->dev.of_node, child) {
246 ret = weim_timing_setup(&pdev->dev, child, devtype);
247 if (ret)
248 dev_warn(&pdev->dev, "%pOF set timing failed.\n",
249 child);
250 else
251 have_child = 1;
252 }
253
254 if (have_child)
255 ret = of_platform_default_populate(pdev->dev.of_node,
256 NULL, &pdev->dev);
257 if (ret)
258 dev_err(&pdev->dev, "%pOF fail to create devices.\n",
259 pdev->dev.of_node);
260 return ret;
261 }
262
weim_probe(struct platform_device * pdev)263 static int weim_probe(struct platform_device *pdev)
264 {
265 struct weim_priv *priv;
266 struct clk *clk;
267 void __iomem *base;
268 int ret;
269
270 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
271 if (!priv)
272 return -ENOMEM;
273
274 /* get the resource */
275 base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
276 if (IS_ERR(base))
277 return PTR_ERR(base);
278
279 priv->base = base;
280 dev_set_drvdata(&pdev->dev, priv);
281
282 /* get the clock */
283 clk = devm_clk_get(&pdev->dev, NULL);
284 if (IS_ERR(clk))
285 return PTR_ERR(clk);
286
287 ret = clk_prepare_enable(clk);
288 if (ret)
289 return ret;
290
291 /* parse the device node */
292 ret = weim_parse_dt(pdev);
293 if (ret)
294 clk_disable_unprepare(clk);
295 else
296 dev_info(&pdev->dev, "Driver registered.\n");
297
298 return ret;
299 }
300
301 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
of_weim_notify(struct notifier_block * nb,unsigned long action,void * arg)302 static int of_weim_notify(struct notifier_block *nb, unsigned long action,
303 void *arg)
304 {
305 const struct imx_weim_devtype *devtype;
306 struct of_reconfig_data *rd = arg;
307 const struct of_device_id *of_id;
308 struct platform_device *pdev;
309 int ret = NOTIFY_OK;
310
311 switch (of_reconfig_get_state_change(action, rd)) {
312 case OF_RECONFIG_CHANGE_ADD:
313 of_id = of_match_node(weim_id_table, rd->dn->parent);
314 if (!of_id)
315 return NOTIFY_OK; /* not for us */
316
317 devtype = of_id->data;
318
319 pdev = of_find_device_by_node(rd->dn->parent);
320 if (!pdev) {
321 pr_err("%s: could not find platform device for '%pOF'\n",
322 __func__, rd->dn->parent);
323
324 return notifier_from_errno(-EINVAL);
325 }
326
327 if (weim_timing_setup(&pdev->dev, rd->dn, devtype))
328 dev_warn(&pdev->dev,
329 "Failed to setup timing for '%pOF'\n", rd->dn);
330
331 if (!of_node_check_flag(rd->dn, OF_POPULATED)) {
332 if (!of_platform_device_create(rd->dn, NULL, &pdev->dev)) {
333 dev_err(&pdev->dev,
334 "Failed to create child device '%pOF'\n",
335 rd->dn);
336 ret = notifier_from_errno(-EINVAL);
337 }
338 }
339
340 platform_device_put(pdev);
341
342 break;
343 case OF_RECONFIG_CHANGE_REMOVE:
344 if (!of_node_check_flag(rd->dn, OF_POPULATED))
345 return NOTIFY_OK; /* device already destroyed */
346
347 of_id = of_match_node(weim_id_table, rd->dn->parent);
348 if (!of_id)
349 return NOTIFY_OK; /* not for us */
350
351 pdev = of_find_device_by_node(rd->dn);
352 if (!pdev) {
353 pr_err("Could not find platform device for '%pOF'\n",
354 rd->dn);
355
356 ret = notifier_from_errno(-EINVAL);
357 } else {
358 of_platform_device_destroy(&pdev->dev, NULL);
359 platform_device_put(pdev);
360 }
361
362 break;
363 default:
364 break;
365 }
366
367 return ret;
368 }
369
370 static struct notifier_block weim_of_notifier = {
371 .notifier_call = of_weim_notify,
372 };
373 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
374
375 static struct platform_driver weim_driver = {
376 .driver = {
377 .name = "imx-weim",
378 .of_match_table = weim_id_table,
379 },
380 .probe = weim_probe,
381 };
382
weim_init(void)383 static int __init weim_init(void)
384 {
385 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
386 WARN_ON(of_reconfig_notifier_register(&weim_of_notifier));
387 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
388
389 return platform_driver_register(&weim_driver);
390 }
391 module_init(weim_init);
392
weim_exit(void)393 static void __exit weim_exit(void)
394 {
395 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
396 of_reconfig_notifier_unregister(&weim_of_notifier);
397 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
398
399 return platform_driver_unregister(&weim_driver);
400
401 }
402 module_exit(weim_exit);
403
404 MODULE_AUTHOR("Freescale Semiconductor Inc.");
405 MODULE_DESCRIPTION("i.MX EIM Controller Driver");
406 MODULE_LICENSE("GPL");
407