1 /*
2 *
3 * Utility functions for the Freescale MPC52xx.
4 *
5 * Copyright (C) 2006 Sylvain Munaut <tnt@246tNt.com>
6 *
7 * This file is licensed under the terms of the GNU General Public License
8 * version 2. This program is licensed "as is" without any warranty of any
9 * kind, whether express or implied.
10 *
11 */
12
13 #undef DEBUG
14
15 #include <linux/gpio.h>
16 #include <linux/kernel.h>
17 #include <linux/spinlock.h>
18 #include <linux/of_address.h>
19 #include <linux/of_platform.h>
20 #include <linux/of_gpio.h>
21 #include <linux/export.h>
22 #include <asm/io.h>
23 #include <asm/mpc52xx.h>
24
25 /* MPC5200 device tree match tables */
26 static const struct of_device_id mpc52xx_xlb_ids[] __initconst = {
27 { .compatible = "fsl,mpc5200-xlb", },
28 { .compatible = "mpc5200-xlb", },
29 {}
30 };
31 static const struct of_device_id mpc52xx_bus_ids[] __initconst = {
32 { .compatible = "fsl,mpc5200-immr", },
33 { .compatible = "fsl,mpc5200b-immr", },
34 { .compatible = "simple-bus", },
35
36 /* depreciated matches; shouldn't be used in new device trees */
37 { .compatible = "fsl,lpb", },
38 { .type = "builtin", .compatible = "mpc5200", }, /* efika */
39 { .type = "soc", .compatible = "mpc5200", }, /* lite5200 */
40 {}
41 };
42
43 /*
44 * This variable is mapped in mpc52xx_map_wdt() and used in mpc52xx_restart().
45 * Permanent mapping is required because mpc52xx_restart() can be called
46 * from interrupt context while node mapping (which calls ioremap())
47 * cannot be used at such point.
48 */
49 static DEFINE_SPINLOCK(mpc52xx_lock);
50 static struct mpc52xx_gpt __iomem *mpc52xx_wdt;
51 static struct mpc52xx_cdm __iomem *mpc52xx_cdm;
52
53 /*
54 * Configure the XLB arbiter settings to match what Linux expects.
55 */
56 void __init
mpc5200_setup_xlb_arbiter(void)57 mpc5200_setup_xlb_arbiter(void)
58 {
59 struct device_node *np;
60 struct mpc52xx_xlb __iomem *xlb;
61
62 np = of_find_matching_node(NULL, mpc52xx_xlb_ids);
63 xlb = of_iomap(np, 0);
64 of_node_put(np);
65 if (!xlb) {
66 printk(KERN_ERR __FILE__ ": "
67 "Error mapping XLB in mpc52xx_setup_cpu(). "
68 "Expect some abnormal behavior\n");
69 return;
70 }
71
72 /* Configure the XLB Arbiter priorities */
73 out_be32(&xlb->master_pri_enable, 0xff);
74 out_be32(&xlb->master_priority, 0x11111111);
75
76 /*
77 * Disable XLB pipelining
78 * (cfr errate 292. We could do this only just before ATA PIO
79 * transaction and re-enable it afterwards ...)
80 * Not needed on MPC5200B.
81 */
82 if ((mfspr(SPRN_SVR) & MPC5200_SVR_MASK) == MPC5200_SVR)
83 out_be32(&xlb->config, in_be32(&xlb->config) | MPC52xx_XLB_CFG_PLDIS);
84
85 iounmap(xlb);
86 }
87
88 /*
89 * This variable is mapped in mpc52xx_map_common_devices and
90 * used in mpc5200_psc_ac97_gpio_reset().
91 */
92 static DEFINE_SPINLOCK(gpio_lock);
93 struct mpc52xx_gpio __iomem *simple_gpio;
94 struct mpc52xx_gpio_wkup __iomem *wkup_gpio;
95
96 /**
97 * mpc52xx_declare_of_platform_devices: register internal devices and children
98 * of the localplus bus to the of_platform
99 * bus.
100 */
mpc52xx_declare_of_platform_devices(void)101 void __init mpc52xx_declare_of_platform_devices(void)
102 {
103 /* Find all the 'platform' devices and register them. */
104 if (of_platform_populate(NULL, mpc52xx_bus_ids, NULL, NULL))
105 pr_err(__FILE__ ": Error while populating devices from DT\n");
106 }
107
108 /*
109 * match tables used by mpc52xx_map_common_devices()
110 */
111 static const struct of_device_id mpc52xx_gpt_ids[] __initconst = {
112 { .compatible = "fsl,mpc5200-gpt", },
113 { .compatible = "mpc5200-gpt", }, /* old */
114 {}
115 };
116 static const struct of_device_id mpc52xx_cdm_ids[] __initconst = {
117 { .compatible = "fsl,mpc5200-cdm", },
118 { .compatible = "mpc5200-cdm", }, /* old */
119 {}
120 };
121 static const struct of_device_id mpc52xx_gpio_simple[] __initconst = {
122 { .compatible = "fsl,mpc5200-gpio", },
123 {}
124 };
125 static const struct of_device_id mpc52xx_gpio_wkup[] __initconst = {
126 { .compatible = "fsl,mpc5200-gpio-wkup", },
127 {}
128 };
129
130
131 /**
132 * mpc52xx_map_common_devices: iomap devices required by common code
133 */
134 void __init
mpc52xx_map_common_devices(void)135 mpc52xx_map_common_devices(void)
136 {
137 struct device_node *np;
138
139 /* mpc52xx_wdt is mapped here and used in mpc52xx_restart,
140 * possibly from a interrupt context. wdt is only implement
141 * on a gpt0, so check has-wdt property before mapping.
142 */
143 for_each_matching_node(np, mpc52xx_gpt_ids) {
144 if (of_property_read_bool(np, "fsl,has-wdt") ||
145 of_property_read_bool(np, "has-wdt")) {
146 mpc52xx_wdt = of_iomap(np, 0);
147 of_node_put(np);
148 break;
149 }
150 }
151
152 /* Clock Distribution Module, used by PSC clock setting function */
153 np = of_find_matching_node(NULL, mpc52xx_cdm_ids);
154 mpc52xx_cdm = of_iomap(np, 0);
155 of_node_put(np);
156
157 /* simple_gpio registers */
158 np = of_find_matching_node(NULL, mpc52xx_gpio_simple);
159 simple_gpio = of_iomap(np, 0);
160 of_node_put(np);
161
162 /* wkup_gpio registers */
163 np = of_find_matching_node(NULL, mpc52xx_gpio_wkup);
164 wkup_gpio = of_iomap(np, 0);
165 of_node_put(np);
166 }
167
168 /**
169 * mpc52xx_set_psc_clkdiv: Set clock divider in the CDM for PSC ports
170 *
171 * @psc_id: id of psc port; must be 1,2,3 or 6
172 * @clkdiv: clock divider value to put into CDM PSC register.
173 */
mpc52xx_set_psc_clkdiv(int psc_id,int clkdiv)174 int mpc52xx_set_psc_clkdiv(int psc_id, int clkdiv)
175 {
176 unsigned long flags;
177 u16 __iomem *reg;
178 u32 val;
179 u32 mask;
180 u32 mclken_div;
181
182 if (!mpc52xx_cdm)
183 return -ENODEV;
184
185 mclken_div = 0x8000 | (clkdiv & 0x1FF);
186 switch (psc_id) {
187 case 1: reg = &mpc52xx_cdm->mclken_div_psc1; mask = 0x20; break;
188 case 2: reg = &mpc52xx_cdm->mclken_div_psc2; mask = 0x40; break;
189 case 3: reg = &mpc52xx_cdm->mclken_div_psc3; mask = 0x80; break;
190 case 6: reg = &mpc52xx_cdm->mclken_div_psc6; mask = 0x10; break;
191 default:
192 return -ENODEV;
193 }
194
195 /* Set the rate and enable the clock */
196 spin_lock_irqsave(&mpc52xx_lock, flags);
197 out_be16(reg, mclken_div);
198 val = in_be32(&mpc52xx_cdm->clk_enables);
199 out_be32(&mpc52xx_cdm->clk_enables, val | mask);
200 spin_unlock_irqrestore(&mpc52xx_lock, flags);
201
202 return 0;
203 }
204 EXPORT_SYMBOL(mpc52xx_set_psc_clkdiv);
205
206 /**
207 * mpc52xx_restart: ppc_md->restart hook for mpc5200 using the watchdog timer
208 */
mpc52xx_restart(char * cmd)209 void __noreturn mpc52xx_restart(char *cmd)
210 {
211 local_irq_disable();
212
213 /* Turn on the watchdog and wait for it to expire.
214 * It effectively does a reset. */
215 if (mpc52xx_wdt) {
216 out_be32(&mpc52xx_wdt->mode, 0x00000000);
217 out_be32(&mpc52xx_wdt->count, 0x000000ff);
218 out_be32(&mpc52xx_wdt->mode, 0x00009004);
219 } else
220 printk(KERN_ERR __FILE__ ": "
221 "mpc52xx_restart: Can't access wdt. "
222 "Restart impossible, system halted.\n");
223
224 while (1);
225 }
226
227 #define PSC1_RESET 0x1
228 #define PSC1_SYNC 0x4
229 #define PSC1_SDATA_OUT 0x1
230 #define PSC2_RESET 0x2
231 #define PSC2_SYNC (0x4<<4)
232 #define PSC2_SDATA_OUT (0x1<<4)
233 #define MPC52xx_GPIO_PSC1_MASK 0x7
234 #define MPC52xx_GPIO_PSC2_MASK (0x7<<4)
235
236 /**
237 * mpc5200_psc_ac97_gpio_reset: Use gpio pins to reset the ac97 bus
238 *
239 * @psc: psc number to reset (only psc 1 and 2 support ac97)
240 */
mpc5200_psc_ac97_gpio_reset(int psc_number)241 int mpc5200_psc_ac97_gpio_reset(int psc_number)
242 {
243 unsigned long flags;
244 u32 gpio;
245 u32 mux;
246 int out;
247 int reset;
248 int sync;
249
250 if ((!simple_gpio) || (!wkup_gpio))
251 return -ENODEV;
252
253 switch (psc_number) {
254 case 0:
255 reset = PSC1_RESET; /* AC97_1_RES */
256 sync = PSC1_SYNC; /* AC97_1_SYNC */
257 out = PSC1_SDATA_OUT; /* AC97_1_SDATA_OUT */
258 gpio = MPC52xx_GPIO_PSC1_MASK;
259 break;
260 case 1:
261 reset = PSC2_RESET; /* AC97_2_RES */
262 sync = PSC2_SYNC; /* AC97_2_SYNC */
263 out = PSC2_SDATA_OUT; /* AC97_2_SDATA_OUT */
264 gpio = MPC52xx_GPIO_PSC2_MASK;
265 break;
266 default:
267 pr_err(__FILE__ ": Unable to determine PSC, no ac97 "
268 "cold-reset will be performed\n");
269 return -ENODEV;
270 }
271
272 spin_lock_irqsave(&gpio_lock, flags);
273
274 /* Reconfigure pin-muxing to gpio */
275 mux = in_be32(&simple_gpio->port_config);
276 out_be32(&simple_gpio->port_config, mux & (~gpio));
277
278 /* enable gpio pins for output */
279 setbits8(&wkup_gpio->wkup_gpioe, reset);
280 setbits32(&simple_gpio->simple_gpioe, sync | out);
281
282 setbits8(&wkup_gpio->wkup_ddr, reset);
283 setbits32(&simple_gpio->simple_ddr, sync | out);
284
285 /* Assert cold reset */
286 clrbits32(&simple_gpio->simple_dvo, sync | out);
287 clrbits8(&wkup_gpio->wkup_dvo, reset);
288
289 /* wait for 1 us */
290 udelay(1);
291
292 /* Deassert reset */
293 setbits8(&wkup_gpio->wkup_dvo, reset);
294
295 /* wait at least 200ns */
296 /* 7 ~= (200ns * timebase) / ns2sec */
297 __delay(7);
298
299 /* Restore pin-muxing */
300 out_be32(&simple_gpio->port_config, mux);
301
302 spin_unlock_irqrestore(&gpio_lock, flags);
303
304 return 0;
305 }
306 EXPORT_SYMBOL(mpc5200_psc_ac97_gpio_reset);
307