1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* Copyright (C) 2019 IBM Corp. */ 3 4 /* Pieces to enable drivers to implement the .set callback */ 5 6 #include "pinmux-aspeed.h" 7 8 static const char *const aspeed_pinmux_ips[] = { 9 [ASPEED_IP_SCU] = "SCU", 10 [ASPEED_IP_GFX] = "GFX", 11 [ASPEED_IP_LPC] = "LPC", 12 }; 13 14 static inline void aspeed_sig_desc_print_val( 15 const struct aspeed_sig_desc *desc, bool enable, u32 rv) 16 { 17 pr_debug("Want %s%X[0x%08X]=0x%X, got 0x%X from 0x%08X\n", 18 aspeed_pinmux_ips[desc->ip], desc->reg, 19 desc->mask, enable ? desc->enable : desc->disable, 20 (rv & desc->mask) >> __ffs(desc->mask), rv); 21 } 22 23 /** 24 * Query the enabled or disabled state of a signal descriptor 25 * 26 * @desc: The signal descriptor of interest 27 * @enabled: True to query the enabled state, false to query disabled state 28 * @map: The IP block's regmap instance 29 * 30 * Return: 1 if the descriptor's bitfield is configured to the state 31 * selected by @enabled, 0 if not, and less than zero if an unrecoverable 32 * failure occurred 33 * 34 * Evaluation of descriptor state is non-trivial in that it is not a binary 35 * outcome: The bitfields can be greater than one bit in size and thus can take 36 * a value that is neither the enabled nor disabled state recorded in the 37 * descriptor (typically this means a different function to the one of interest 38 * is enabled). Thus we must explicitly test for either condition as required. 39 */ 40 int aspeed_sig_desc_eval(const struct aspeed_sig_desc *desc, 41 bool enabled, struct regmap *map) 42 { 43 int ret; 44 unsigned int raw; 45 u32 want; 46 47 if (!map) 48 return -ENODEV; 49 50 ret = regmap_read(map, desc->reg, &raw); 51 if (ret) 52 return ret; 53 54 aspeed_sig_desc_print_val(desc, enabled, raw); 55 want = enabled ? desc->enable : desc->disable; 56 57 return ((raw & desc->mask) >> __ffs(desc->mask)) == want; 58 } 59 60 /** 61 * Query the enabled or disabled state for a mux function's signal on a pin 62 * 63 * @ctx: The driver context for the pinctrl IP 64 * @expr: An expression controlling the signal for a mux function on a pin 65 * @enabled: True to query the enabled state, false to query disabled state 66 * 67 * Return: 1 if the expression composed by @enabled evaluates true, 0 if not, 68 * and less than zero if an unrecoverable failure occurred. 69 * 70 * A mux function is enabled or disabled if the function's signal expression 71 * for each pin in the function's pin group evaluates true for the desired 72 * state. An signal expression evaluates true if all of its associated signal 73 * descriptors evaluate true for the desired state. 74 * 75 * If an expression's state is described by more than one bit, either through 76 * multi-bit bitfields in a single signal descriptor or through multiple signal 77 * descriptors of a single bit then it is possible for the expression to be in 78 * neither the enabled nor disabled state. Thus we must explicitly test for 79 * either condition as required. 80 */ 81 int aspeed_sig_expr_eval(struct aspeed_pinmux_data *ctx, 82 const struct aspeed_sig_expr *expr, bool enabled) 83 { 84 int ret; 85 int i; 86 87 if (ctx->ops->eval) 88 return ctx->ops->eval(ctx, expr, enabled); 89 90 for (i = 0; i < expr->ndescs; i++) { 91 const struct aspeed_sig_desc *desc = &expr->descs[i]; 92 93 ret = aspeed_sig_desc_eval(desc, enabled, ctx->maps[desc->ip]); 94 if (ret <= 0) 95 return ret; 96 } 97 98 return 1; 99 } 100