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 */
26static const struct of_device_id mpc52xx_xlb_ids[] __initconst = {
27	{ .compatible = "fsl,mpc5200-xlb", },
28	{ .compatible = "mpc5200-xlb", },
29	{}
30};
31static 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 */
49static DEFINE_SPINLOCK(mpc52xx_lock);
50static struct mpc52xx_gpt __iomem *mpc52xx_wdt;
51static struct mpc52xx_cdm __iomem *mpc52xx_cdm;
52
53/*
54 * Configure the XLB arbiter settings to match what Linux expects.
55 */
56void __init
57mpc5200_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 */
92static DEFINE_SPINLOCK(gpio_lock);
93struct mpc52xx_gpio __iomem *simple_gpio;
94struct 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 */
101void __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 */
111static const struct of_device_id mpc52xx_gpt_ids[] __initconst = {
112	{ .compatible = "fsl,mpc5200-gpt", },
113	{ .compatible = "mpc5200-gpt", }, /* old */
114	{}
115};
116static const struct of_device_id mpc52xx_cdm_ids[] __initconst = {
117	{ .compatible = "fsl,mpc5200-cdm", },
118	{ .compatible = "mpc5200-cdm", }, /* old */
119	{}
120};
121static const struct of_device_id mpc52xx_gpio_simple[] __initconst = {
122	{ .compatible = "fsl,mpc5200-gpio", },
123	{}
124};
125static 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 */
134void __init
135mpc52xx_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 */
174int 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}
204EXPORT_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 */
214unsigned 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}
241EXPORT_SYMBOL(mpc52xx_get_xtal_freq);
242
243/**
244 * mpc52xx_restart: ppc_md->restart hook for mpc5200 using the watchdog timer
245 */
246void
247mpc52xx_restart(char *cmd)
248{
249	local_irq_disable();
250
251	/* Turn on the watchdog and wait for it to expire.
252	 * It effectively does a reset. */
253	if (mpc52xx_wdt) {
254		out_be32(&mpc52xx_wdt->mode, 0x00000000);
255		out_be32(&mpc52xx_wdt->count, 0x000000ff);
256		out_be32(&mpc52xx_wdt->mode, 0x00009004);
257	} else
258		printk(KERN_ERR __FILE__ ": "
259			"mpc52xx_restart: Can't access wdt. "
260			"Restart impossible, system halted.\n");
261
262	while (1);
263}
264
265#define PSC1_RESET     0x1
266#define PSC1_SYNC      0x4
267#define PSC1_SDATA_OUT 0x1
268#define PSC2_RESET     0x2
269#define PSC2_SYNC      (0x4<<4)
270#define PSC2_SDATA_OUT (0x1<<4)
271#define MPC52xx_GPIO_PSC1_MASK 0x7
272#define MPC52xx_GPIO_PSC2_MASK (0x7<<4)
273
274/**
275 * mpc5200_psc_ac97_gpio_reset: Use gpio pins to reset the ac97 bus
276 *
277 * @psc: psc number to reset (only psc 1 and 2 support ac97)
278 */
279int mpc5200_psc_ac97_gpio_reset(int psc_number)
280{
281	unsigned long flags;
282	u32 gpio;
283	u32 mux;
284	int out;
285	int reset;
286	int sync;
287
288	if ((!simple_gpio) || (!wkup_gpio))
289		return -ENODEV;
290
291	switch (psc_number) {
292	case 0:
293		reset   = PSC1_RESET;           /* AC97_1_RES */
294		sync    = PSC1_SYNC;            /* AC97_1_SYNC */
295		out     = PSC1_SDATA_OUT;       /* AC97_1_SDATA_OUT */
296		gpio    = MPC52xx_GPIO_PSC1_MASK;
297		break;
298	case 1:
299		reset   = PSC2_RESET;           /* AC97_2_RES */
300		sync    = PSC2_SYNC;            /* AC97_2_SYNC */
301		out     = PSC2_SDATA_OUT;       /* AC97_2_SDATA_OUT */
302		gpio    = MPC52xx_GPIO_PSC2_MASK;
303		break;
304	default:
305		pr_err(__FILE__ ": Unable to determine PSC, no ac97 "
306		       "cold-reset will be performed\n");
307		return -ENODEV;
308	}
309
310	spin_lock_irqsave(&gpio_lock, flags);
311
312	/* Reconfiure pin-muxing to gpio */
313	mux = in_be32(&simple_gpio->port_config);
314	out_be32(&simple_gpio->port_config, mux & (~gpio));
315
316	/* enable gpio pins for output */
317	setbits8(&wkup_gpio->wkup_gpioe, reset);
318	setbits32(&simple_gpio->simple_gpioe, sync | out);
319
320	setbits8(&wkup_gpio->wkup_ddr, reset);
321	setbits32(&simple_gpio->simple_ddr, sync | out);
322
323	/* Assert cold reset */
324	clrbits32(&simple_gpio->simple_dvo, sync | out);
325	clrbits8(&wkup_gpio->wkup_dvo, reset);
326
327	/* wait for 1 us */
328	udelay(1);
329
330	/* Deassert reset */
331	setbits8(&wkup_gpio->wkup_dvo, reset);
332
333	/* wait at least 200ns */
334	/* 7 ~= (200ns * timebase) / ns2sec */
335	__delay(7);
336
337	/* Restore pin-muxing */
338	out_be32(&simple_gpio->port_config, mux);
339
340	spin_unlock_irqrestore(&gpio_lock, flags);
341
342	return 0;
343}
344EXPORT_SYMBOL(mpc5200_psc_ac97_gpio_reset);
345