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mfp.c
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1 /*
2  * linux/arch/arm/plat-pxa/mfp.c
3  *
4  * Multi-Function Pin Support
5  *
6  * Copyright (C) 2007 Marvell Internation Ltd.
7  *
8  * 2007-08-21: eric miao <[email protected]>
9  * initial version
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License version 2 as
13  * published by the Free Software Foundation.
14  */
15 
16 #include <linux/module.h>
17 #include <linux/kernel.h>
18 #include <linux/init.h>
19 #include <linux/io.h>
20 
21 #include <plat/mfp.h>
22 
23 #define MFPR_SIZE (PAGE_SIZE)
24 
25 /* MFPR register bit definitions */
26 #define MFPR_PULL_SEL (0x1 << 15)
27 #define MFPR_PULLUP_EN (0x1 << 14)
28 #define MFPR_PULLDOWN_EN (0x1 << 13)
29 #define MFPR_SLEEP_SEL (0x1 << 9)
30 #define MFPR_SLEEP_OE_N (0x1 << 7)
31 #define MFPR_EDGE_CLEAR (0x1 << 6)
32 #define MFPR_EDGE_FALL_EN (0x1 << 5)
33 #define MFPR_EDGE_RISE_EN (0x1 << 4)
34 
35 #define MFPR_SLEEP_DATA(x) ((x) << 8)
36 #define MFPR_DRIVE(x) (((x) & 0x7) << 10)
37 #define MFPR_AF_SEL(x) (((x) & 0x7) << 0)
38 
39 #define MFPR_EDGE_NONE (0)
40 #define MFPR_EDGE_RISE (MFPR_EDGE_RISE_EN)
41 #define MFPR_EDGE_FALL (MFPR_EDGE_FALL_EN)
42 #define MFPR_EDGE_BOTH (MFPR_EDGE_RISE | MFPR_EDGE_FALL)
43 
44 /*
45  * Table that determines the low power modes outputs, with actual settings
46  * used in parentheses for don't-care values. Except for the float output,
47  * the configured driven and pulled levels match, so if there is a need for
48  * non-LPM pulled output, the same configuration could probably be used.
49  *
50  * Output value sleep_oe_n sleep_data pullup_en pulldown_en pull_sel
51  * (bit 7) (bit 8) (bit 14) (bit 13) (bit 15)
52  *
53  * Input 0 X(0) X(0) X(0) 0
54  * Drive 0 0 0 0 X(1) 0
55  * Drive 1 0 1 X(1) 0 0
56  * Pull hi (1) 1 X(1) 1 0 0
57  * Pull lo (0) 1 X(0) 0 1 0
58  * Z (float) 1 X(0) 0 0 0
59  */
60 #define MFPR_LPM_INPUT (0)
61 #define MFPR_LPM_DRIVE_LOW (MFPR_SLEEP_DATA(0) | MFPR_PULLDOWN_EN)
62 #define MFPR_LPM_DRIVE_HIGH (MFPR_SLEEP_DATA(1) | MFPR_PULLUP_EN)
63 #define MFPR_LPM_PULL_LOW (MFPR_LPM_DRIVE_LOW | MFPR_SLEEP_OE_N)
64 #define MFPR_LPM_PULL_HIGH (MFPR_LPM_DRIVE_HIGH | MFPR_SLEEP_OE_N)
65 #define MFPR_LPM_FLOAT (MFPR_SLEEP_OE_N)
66 #define MFPR_LPM_MASK (0xe080)
67 
68 /*
69  * The pullup and pulldown state of the MFP pin at run mode is by default
70  * determined by the selected alternate function. In case that some buggy
71  * devices need to override this default behavior, the definitions below
72  * indicates the setting of corresponding MFPR bits
73  *
74  * Definition pull_sel pullup_en pulldown_en
75  * MFPR_PULL_NONE 0 0 0
76  * MFPR_PULL_LOW 1 0 1
77  * MFPR_PULL_HIGH 1 1 0
78  * MFPR_PULL_BOTH 1 1 1
79  * MFPR_PULL_FLOAT 1 0 0
80  */
81 #define MFPR_PULL_NONE (0)
82 #define MFPR_PULL_LOW (MFPR_PULL_SEL | MFPR_PULLDOWN_EN)
83 #define MFPR_PULL_BOTH (MFPR_PULL_LOW | MFPR_PULLUP_EN)
84 #define MFPR_PULL_HIGH (MFPR_PULL_SEL | MFPR_PULLUP_EN)
85 #define MFPR_PULL_FLOAT (MFPR_PULL_SEL)
86 
87 /* mfp_spin_lock is used to ensure that MFP register configuration
88  * (most likely a read-modify-write operation) is atomic, and that
89  * mfp_table[] is consistent
90  */
91 static DEFINE_SPINLOCK(mfp_spin_lock);
92 
93 static void __iomem *mfpr_mmio_base;
94 
95 struct mfp_pin {
96  unsigned long config; /* -1 for not configured */
97  unsigned long mfpr_off; /* MFPRxx Register offset */
98  unsigned long mfpr_run; /* Run-Mode Register Value */
99  unsigned long mfpr_lpm; /* Low Power Mode Register Value */
100 };
101 
102 static struct mfp_pin mfp_table[MFP_PIN_MAX];
103 
104 /* mapping of MFP_LPM_* definitions to MFPR_LPM_* register bits */
105 static const unsigned long mfpr_lpm[] = {
113 };
114 
115 /* mapping of MFP_PULL_* definitions to MFPR_PULL_* register bits */
116 static const unsigned long mfpr_pull[] = {
122 };
123 
124 /* mapping of MFP_LPM_EDGE_* definitions to MFPR_EDGE_* register bits */
125 static const unsigned long mfpr_edge[] = {
130 };
131 
132 #define mfpr_readl(off) \
133  __raw_readl(mfpr_mmio_base + (off))
134 
135 #define mfpr_writel(off, val) \
136  __raw_writel(val, mfpr_mmio_base + (off))
137 
138 #define mfp_configured(p) ((p)->config != -1)
139 
140 /*
141  * perform a read-back of any valid MFPR register to make sure the
142  * previous writings are finished
143  */
144 static unsigned long mfpr_off_readback;
145 #define mfpr_sync() (void)__raw_readl(mfpr_mmio_base + mfpr_off_readback)
146 
147 static inline void __mfp_config_run(struct mfp_pin *p)
148 {
149  if (mfp_configured(p))
150  mfpr_writel(p->mfpr_off, p->mfpr_run);
151 }
152 
153 static inline void __mfp_config_lpm(struct mfp_pin *p)
154 {
155  if (mfp_configured(p)) {
156  unsigned long mfpr_clr = (p->mfpr_run & ~MFPR_EDGE_BOTH) | MFPR_EDGE_CLEAR;
157  if (mfpr_clr != p->mfpr_run)
158  mfpr_writel(p->mfpr_off, mfpr_clr);
159  if (p->mfpr_lpm != mfpr_clr)
160  mfpr_writel(p->mfpr_off, p->mfpr_lpm);
161  }
162 }
163 
164 void mfp_config(unsigned long *mfp_cfgs, int num)
165 {
166  unsigned long flags;
167  int i;
168 
169  spin_lock_irqsave(&mfp_spin_lock, flags);
170 
171  for (i = 0; i < num; i++, mfp_cfgs++) {
172  unsigned long tmp, c = *mfp_cfgs;
173  struct mfp_pin *p;
174  int pin, af, drv, lpm, edge, pull;
175 
176  pin = MFP_PIN(c);
177  BUG_ON(pin >= MFP_PIN_MAX);
178  p = &mfp_table[pin];
179 
180  af = MFP_AF(c);
181  drv = MFP_DS(c);
182  lpm = MFP_LPM_STATE(c);
183  edge = MFP_LPM_EDGE(c);
184  pull = MFP_PULL(c);
185 
186  /* run-mode pull settings will conflict with MFPR bits of
187  * low power mode state, calculate mfpr_run and mfpr_lpm
188  * individually if pull != MFP_PULL_NONE
189  */
190  tmp = MFPR_AF_SEL(af) | MFPR_DRIVE(drv);
191 
192  if (likely(pull == MFP_PULL_NONE)) {
193  p->mfpr_run = tmp | mfpr_lpm[lpm] | mfpr_edge[edge];
194  p->mfpr_lpm = p->mfpr_run;
195  } else {
196  p->mfpr_lpm = tmp | mfpr_lpm[lpm] | mfpr_edge[edge];
197  p->mfpr_run = tmp | mfpr_pull[pull];
198  }
199 
200  p->config = c; __mfp_config_run(p);
201  }
202 
203  mfpr_sync();
204  spin_unlock_irqrestore(&mfp_spin_lock, flags);
205 }
206 
207 unsigned long mfp_read(int mfp)
208 {
209  unsigned long val, flags;
210 
211  BUG_ON(mfp < 0 || mfp >= MFP_PIN_MAX);
212 
213  spin_lock_irqsave(&mfp_spin_lock, flags);
214  val = mfpr_readl(mfp_table[mfp].mfpr_off);
215  spin_unlock_irqrestore(&mfp_spin_lock, flags);
216 
217  return val;
218 }
219 
220 void mfp_write(int mfp, unsigned long val)
221 {
222  unsigned long flags;
223 
224  BUG_ON(mfp < 0 || mfp >= MFP_PIN_MAX);
225 
226  spin_lock_irqsave(&mfp_spin_lock, flags);
227  mfpr_writel(mfp_table[mfp].mfpr_off, val);
228  mfpr_sync();
229  spin_unlock_irqrestore(&mfp_spin_lock, flags);
230 }
231 
232 void __init mfp_init_base(void __iomem *mfpr_base)
233 {
234  int i;
235 
236  /* initialize the table with default - unconfigured */
237  for (i = 0; i < ARRAY_SIZE(mfp_table); i++)
238  mfp_table[i].config = -1;
239 
240  mfpr_mmio_base = mfpr_base;
241 }
242 
243 void __init mfp_init_addr(struct mfp_addr_map *map)
244 {
245  struct mfp_addr_map *p;
246  unsigned long offset, flags;
247  int i;
248 
249  spin_lock_irqsave(&mfp_spin_lock, flags);
250 
251  /* mfp offset for readback */
252  mfpr_off_readback = map[0].offset;
253 
254  for (p = map; p->start != MFP_PIN_INVALID; p++) {
255  offset = p->offset;
256  i = p->start;
257 
258  do {
259  mfp_table[i].mfpr_off = offset;
260  mfp_table[i].mfpr_run = 0;
261  mfp_table[i].mfpr_lpm = 0;
262  offset += 4; i++;
263  } while ((i <= p->end) && (p->end != -1));
264  }
265 
266  spin_unlock_irqrestore(&mfp_spin_lock, flags);
267 }
268 
269 void mfp_config_lpm(void)
270 {
271  struct mfp_pin *p = &mfp_table[0];
272  int pin;
273 
274  for (pin = 0; pin < ARRAY_SIZE(mfp_table); pin++, p++)
275  __mfp_config_lpm(p);
276 }
277 
278 void mfp_config_run(void)
279 {
280  struct mfp_pin *p = &mfp_table[0];
281  int pin;
282 
283  for (pin = 0; pin < ARRAY_SIZE(mfp_table); pin++, p++)
284  __mfp_config_run(p);
285 }