mfp.c 7.5 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * linux/arch/arm/plat-pxa/mfp.c
  4. *
  5. * Multi-Function Pin Support
  6. *
  7. * Copyright (C) 2007 Marvell Internation Ltd.
  8. *
  9. * 2007-08-21: eric miao <[email protected]>
  10. * initial version
  11. */
  12. #include <linux/module.h>
  13. #include <linux/kernel.h>
  14. #include <linux/init.h>
  15. #include <linux/io.h>
  16. #include <linux/soc/pxa/mfp.h>
  17. #define MFPR_SIZE (PAGE_SIZE)
  18. /* MFPR register bit definitions */
  19. #define MFPR_PULL_SEL (0x1 << 15)
  20. #define MFPR_PULLUP_EN (0x1 << 14)
  21. #define MFPR_PULLDOWN_EN (0x1 << 13)
  22. #define MFPR_SLEEP_SEL (0x1 << 9)
  23. #define MFPR_SLEEP_OE_N (0x1 << 7)
  24. #define MFPR_EDGE_CLEAR (0x1 << 6)
  25. #define MFPR_EDGE_FALL_EN (0x1 << 5)
  26. #define MFPR_EDGE_RISE_EN (0x1 << 4)
  27. #define MFPR_SLEEP_DATA(x) ((x) << 8)
  28. #define MFPR_DRIVE(x) (((x) & 0x7) << 10)
  29. #define MFPR_AF_SEL(x) (((x) & 0x7) << 0)
  30. #define MFPR_EDGE_NONE (0)
  31. #define MFPR_EDGE_RISE (MFPR_EDGE_RISE_EN)
  32. #define MFPR_EDGE_FALL (MFPR_EDGE_FALL_EN)
  33. #define MFPR_EDGE_BOTH (MFPR_EDGE_RISE | MFPR_EDGE_FALL)
  34. /*
  35. * Table that determines the low power modes outputs, with actual settings
  36. * used in parentheses for don't-care values. Except for the float output,
  37. * the configured driven and pulled levels match, so if there is a need for
  38. * non-LPM pulled output, the same configuration could probably be used.
  39. *
  40. * Output value sleep_oe_n sleep_data pullup_en pulldown_en pull_sel
  41. * (bit 7) (bit 8) (bit 14) (bit 13) (bit 15)
  42. *
  43. * Input 0 X(0) X(0) X(0) 0
  44. * Drive 0 0 0 0 X(1) 0
  45. * Drive 1 0 1 X(1) 0 0
  46. * Pull hi (1) 1 X(1) 1 0 0
  47. * Pull lo (0) 1 X(0) 0 1 0
  48. * Z (float) 1 X(0) 0 0 0
  49. */
  50. #define MFPR_LPM_INPUT (0)
  51. #define MFPR_LPM_DRIVE_LOW (MFPR_SLEEP_DATA(0) | MFPR_PULLDOWN_EN)
  52. #define MFPR_LPM_DRIVE_HIGH (MFPR_SLEEP_DATA(1) | MFPR_PULLUP_EN)
  53. #define MFPR_LPM_PULL_LOW (MFPR_LPM_DRIVE_LOW | MFPR_SLEEP_OE_N)
  54. #define MFPR_LPM_PULL_HIGH (MFPR_LPM_DRIVE_HIGH | MFPR_SLEEP_OE_N)
  55. #define MFPR_LPM_FLOAT (MFPR_SLEEP_OE_N)
  56. #define MFPR_LPM_MASK (0xe080)
  57. /*
  58. * The pullup and pulldown state of the MFP pin at run mode is by default
  59. * determined by the selected alternate function. In case that some buggy
  60. * devices need to override this default behavior, the definitions below
  61. * indicates the setting of corresponding MFPR bits
  62. *
  63. * Definition pull_sel pullup_en pulldown_en
  64. * MFPR_PULL_NONE 0 0 0
  65. * MFPR_PULL_LOW 1 0 1
  66. * MFPR_PULL_HIGH 1 1 0
  67. * MFPR_PULL_BOTH 1 1 1
  68. * MFPR_PULL_FLOAT 1 0 0
  69. */
  70. #define MFPR_PULL_NONE (0)
  71. #define MFPR_PULL_LOW (MFPR_PULL_SEL | MFPR_PULLDOWN_EN)
  72. #define MFPR_PULL_BOTH (MFPR_PULL_LOW | MFPR_PULLUP_EN)
  73. #define MFPR_PULL_HIGH (MFPR_PULL_SEL | MFPR_PULLUP_EN)
  74. #define MFPR_PULL_FLOAT (MFPR_PULL_SEL)
  75. /* mfp_spin_lock is used to ensure that MFP register configuration
  76. * (most likely a read-modify-write operation) is atomic, and that
  77. * mfp_table[] is consistent
  78. */
  79. static DEFINE_SPINLOCK(mfp_spin_lock);
  80. static void __iomem *mfpr_mmio_base;
  81. struct mfp_pin {
  82. unsigned long config; /* -1 for not configured */
  83. unsigned long mfpr_off; /* MFPRxx Register offset */
  84. unsigned long mfpr_run; /* Run-Mode Register Value */
  85. unsigned long mfpr_lpm; /* Low Power Mode Register Value */
  86. };
  87. static struct mfp_pin mfp_table[MFP_PIN_MAX];
  88. /* mapping of MFP_LPM_* definitions to MFPR_LPM_* register bits */
  89. static const unsigned long mfpr_lpm[] = {
  90. MFPR_LPM_INPUT,
  91. MFPR_LPM_DRIVE_LOW,
  92. MFPR_LPM_DRIVE_HIGH,
  93. MFPR_LPM_PULL_LOW,
  94. MFPR_LPM_PULL_HIGH,
  95. MFPR_LPM_FLOAT,
  96. MFPR_LPM_INPUT,
  97. };
  98. /* mapping of MFP_PULL_* definitions to MFPR_PULL_* register bits */
  99. static const unsigned long mfpr_pull[] = {
  100. MFPR_PULL_NONE,
  101. MFPR_PULL_LOW,
  102. MFPR_PULL_HIGH,
  103. MFPR_PULL_BOTH,
  104. MFPR_PULL_FLOAT,
  105. };
  106. /* mapping of MFP_LPM_EDGE_* definitions to MFPR_EDGE_* register bits */
  107. static const unsigned long mfpr_edge[] = {
  108. MFPR_EDGE_NONE,
  109. MFPR_EDGE_RISE,
  110. MFPR_EDGE_FALL,
  111. MFPR_EDGE_BOTH,
  112. };
  113. #define mfpr_readl(off) \
  114. __raw_readl(mfpr_mmio_base + (off))
  115. #define mfpr_writel(off, val) \
  116. __raw_writel(val, mfpr_mmio_base + (off))
  117. #define mfp_configured(p) ((p)->config != -1)
  118. /*
  119. * perform a read-back of any valid MFPR register to make sure the
  120. * previous writings are finished
  121. */
  122. static unsigned long mfpr_off_readback;
  123. #define mfpr_sync() (void)__raw_readl(mfpr_mmio_base + mfpr_off_readback)
  124. static inline void __mfp_config_run(struct mfp_pin *p)
  125. {
  126. if (mfp_configured(p))
  127. mfpr_writel(p->mfpr_off, p->mfpr_run);
  128. }
  129. static inline void __mfp_config_lpm(struct mfp_pin *p)
  130. {
  131. if (mfp_configured(p)) {
  132. unsigned long mfpr_clr = (p->mfpr_run & ~MFPR_EDGE_BOTH) | MFPR_EDGE_CLEAR;
  133. if (mfpr_clr != p->mfpr_run)
  134. mfpr_writel(p->mfpr_off, mfpr_clr);
  135. if (p->mfpr_lpm != mfpr_clr)
  136. mfpr_writel(p->mfpr_off, p->mfpr_lpm);
  137. }
  138. }
  139. void mfp_config(unsigned long *mfp_cfgs, int num)
  140. {
  141. unsigned long flags;
  142. int i;
  143. spin_lock_irqsave(&mfp_spin_lock, flags);
  144. for (i = 0; i < num; i++, mfp_cfgs++) {
  145. unsigned long tmp, c = *mfp_cfgs;
  146. struct mfp_pin *p;
  147. int pin, af, drv, lpm, edge, pull;
  148. pin = MFP_PIN(c);
  149. BUG_ON(pin >= MFP_PIN_MAX);
  150. p = &mfp_table[pin];
  151. af = MFP_AF(c);
  152. drv = MFP_DS(c);
  153. lpm = MFP_LPM_STATE(c);
  154. edge = MFP_LPM_EDGE(c);
  155. pull = MFP_PULL(c);
  156. /* run-mode pull settings will conflict with MFPR bits of
  157. * low power mode state, calculate mfpr_run and mfpr_lpm
  158. * individually if pull != MFP_PULL_NONE
  159. */
  160. tmp = MFPR_AF_SEL(af) | MFPR_DRIVE(drv);
  161. if (likely(pull == MFP_PULL_NONE)) {
  162. p->mfpr_run = tmp | mfpr_lpm[lpm] | mfpr_edge[edge];
  163. p->mfpr_lpm = p->mfpr_run;
  164. } else {
  165. p->mfpr_lpm = tmp | mfpr_lpm[lpm] | mfpr_edge[edge];
  166. p->mfpr_run = tmp | mfpr_pull[pull];
  167. }
  168. p->config = c; __mfp_config_run(p);
  169. }
  170. mfpr_sync();
  171. spin_unlock_irqrestore(&mfp_spin_lock, flags);
  172. }
  173. unsigned long mfp_read(int mfp)
  174. {
  175. unsigned long val, flags;
  176. BUG_ON(mfp < 0 || mfp >= MFP_PIN_MAX);
  177. spin_lock_irqsave(&mfp_spin_lock, flags);
  178. val = mfpr_readl(mfp_table[mfp].mfpr_off);
  179. spin_unlock_irqrestore(&mfp_spin_lock, flags);
  180. return val;
  181. }
  182. void mfp_write(int mfp, unsigned long val)
  183. {
  184. unsigned long flags;
  185. BUG_ON(mfp < 0 || mfp >= MFP_PIN_MAX);
  186. spin_lock_irqsave(&mfp_spin_lock, flags);
  187. mfpr_writel(mfp_table[mfp].mfpr_off, val);
  188. mfpr_sync();
  189. spin_unlock_irqrestore(&mfp_spin_lock, flags);
  190. }
  191. void __init mfp_init_base(void __iomem *mfpr_base)
  192. {
  193. int i;
  194. /* initialize the table with default - unconfigured */
  195. for (i = 0; i < ARRAY_SIZE(mfp_table); i++)
  196. mfp_table[i].config = -1;
  197. mfpr_mmio_base = mfpr_base;
  198. }
  199. void __init mfp_init_addr(struct mfp_addr_map *map)
  200. {
  201. struct mfp_addr_map *p;
  202. unsigned long offset, flags;
  203. int i;
  204. spin_lock_irqsave(&mfp_spin_lock, flags);
  205. /* mfp offset for readback */
  206. mfpr_off_readback = map[0].offset;
  207. for (p = map; p->start != MFP_PIN_INVALID; p++) {
  208. offset = p->offset;
  209. i = p->start;
  210. do {
  211. mfp_table[i].mfpr_off = offset;
  212. mfp_table[i].mfpr_run = 0;
  213. mfp_table[i].mfpr_lpm = 0;
  214. offset += 4; i++;
  215. } while ((i <= p->end) && (p->end != -1));
  216. }
  217. spin_unlock_irqrestore(&mfp_spin_lock, flags);
  218. }
  219. void mfp_config_lpm(void)
  220. {
  221. struct mfp_pin *p = &mfp_table[0];
  222. int pin;
  223. for (pin = 0; pin < ARRAY_SIZE(mfp_table); pin++, p++)
  224. __mfp_config_lpm(p);
  225. }
  226. void mfp_config_run(void)
  227. {
  228. struct mfp_pin *p = &mfp_table[0];
  229. int pin;
  230. for (pin = 0; pin < ARRAY_SIZE(mfp_table); pin++, p++)
  231. __mfp_config_run(p);
  232. }