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_platform.h>
19 #include <linux/of_gpio.h>
20 #include <linux/export.h>
21 #include <asm/io.h>
22 #include <asm/prom.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_get_property(np, "fsl,has-wdt", NULL) ||
145 		    of_get_property(np, "has-wdt", NULL)) {
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_get_xtal_freq - Get SYS_XTAL_IN frequency for a device
208  *
209  * @node: device node
210  *
211  * Returns the frequency of the external oscillator clock connected
212  * to the SYS_XTAL_IN pin, or 0 if it cannot be determined.
213  */
mpc52xx_get_xtal_freq(struct device_node * node)214 unsigned int mpc52xx_get_xtal_freq(struct device_node *node)
215 {
216 	u32 val;
217 	unsigned int freq;
218 
219 	if (!mpc52xx_cdm)
220 		return 0;
221 
222 	freq = mpc5xxx_get_bus_frequency(node);
223 	if (!freq)
224 		return 0;
225 
226 	if (in_8(&mpc52xx_cdm->ipb_clk_sel) & 0x1)
227 		freq *= 2;
228 
229 	val  = in_be32(&mpc52xx_cdm->rstcfg);
230 	if (val & (1 << 5))
231 		freq *= 8;
232 	else
233 		freq *= 4;
234 	if (val & (1 << 6))
235 		freq /= 12;
236 	else
237 		freq /= 16;
238 
239 	return freq;
240 }
241 EXPORT_SYMBOL(mpc52xx_get_xtal_freq);
242 
243 /**
244  * mpc52xx_restart: ppc_md->restart hook for mpc5200 using the watchdog timer
245  */
mpc52xx_restart(char * cmd)246 void __noreturn mpc52xx_restart(char *cmd)
247 {
248 	local_irq_disable();
249 
250 	/* Turn on the watchdog and wait for it to expire.
251 	 * It effectively does a reset. */
252 	if (mpc52xx_wdt) {
253 		out_be32(&mpc52xx_wdt->mode, 0x00000000);
254 		out_be32(&mpc52xx_wdt->count, 0x000000ff);
255 		out_be32(&mpc52xx_wdt->mode, 0x00009004);
256 	} else
257 		printk(KERN_ERR __FILE__ ": "
258 			"mpc52xx_restart: Can't access wdt. "
259 			"Restart impossible, system halted.\n");
260 
261 	while (1);
262 }
263 
264 #define PSC1_RESET     0x1
265 #define PSC1_SYNC      0x4
266 #define PSC1_SDATA_OUT 0x1
267 #define PSC2_RESET     0x2
268 #define PSC2_SYNC      (0x4<<4)
269 #define PSC2_SDATA_OUT (0x1<<4)
270 #define MPC52xx_GPIO_PSC1_MASK 0x7
271 #define MPC52xx_GPIO_PSC2_MASK (0x7<<4)
272 
273 /**
274  * mpc5200_psc_ac97_gpio_reset: Use gpio pins to reset the ac97 bus
275  *
276  * @psc: psc number to reset (only psc 1 and 2 support ac97)
277  */
mpc5200_psc_ac97_gpio_reset(int psc_number)278 int mpc5200_psc_ac97_gpio_reset(int psc_number)
279 {
280 	unsigned long flags;
281 	u32 gpio;
282 	u32 mux;
283 	int out;
284 	int reset;
285 	int sync;
286 
287 	if ((!simple_gpio) || (!wkup_gpio))
288 		return -ENODEV;
289 
290 	switch (psc_number) {
291 	case 0:
292 		reset   = PSC1_RESET;           /* AC97_1_RES */
293 		sync    = PSC1_SYNC;            /* AC97_1_SYNC */
294 		out     = PSC1_SDATA_OUT;       /* AC97_1_SDATA_OUT */
295 		gpio    = MPC52xx_GPIO_PSC1_MASK;
296 		break;
297 	case 1:
298 		reset   = PSC2_RESET;           /* AC97_2_RES */
299 		sync    = PSC2_SYNC;            /* AC97_2_SYNC */
300 		out     = PSC2_SDATA_OUT;       /* AC97_2_SDATA_OUT */
301 		gpio    = MPC52xx_GPIO_PSC2_MASK;
302 		break;
303 	default:
304 		pr_err(__FILE__ ": Unable to determine PSC, no ac97 "
305 		       "cold-reset will be performed\n");
306 		return -ENODEV;
307 	}
308 
309 	spin_lock_irqsave(&gpio_lock, flags);
310 
311 	/* Reconfiure pin-muxing to gpio */
312 	mux = in_be32(&simple_gpio->port_config);
313 	out_be32(&simple_gpio->port_config, mux & (~gpio));
314 
315 	/* enable gpio pins for output */
316 	setbits8(&wkup_gpio->wkup_gpioe, reset);
317 	setbits32(&simple_gpio->simple_gpioe, sync | out);
318 
319 	setbits8(&wkup_gpio->wkup_ddr, reset);
320 	setbits32(&simple_gpio->simple_ddr, sync | out);
321 
322 	/* Assert cold reset */
323 	clrbits32(&simple_gpio->simple_dvo, sync | out);
324 	clrbits8(&wkup_gpio->wkup_dvo, reset);
325 
326 	/* wait for 1 us */
327 	udelay(1);
328 
329 	/* Deassert reset */
330 	setbits8(&wkup_gpio->wkup_dvo, reset);
331 
332 	/* wait at least 200ns */
333 	/* 7 ~= (200ns * timebase) / ns2sec */
334 	__delay(7);
335 
336 	/* Restore pin-muxing */
337 	out_be32(&simple_gpio->port_config, mux);
338 
339 	spin_unlock_irqrestore(&gpio_lock, flags);
340 
341 	return 0;
342 }
343 EXPORT_SYMBOL(mpc5200_psc_ac97_gpio_reset);
344