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// SPDX-License-Identifier: GPL-2.0-or-later
/* Copyright (C) 2019 IBM Corp. */
/* Pieces to enable drivers to implement the .set callback */
#include "pinmux-aspeed.h"
static const char *const aspeed_pinmux_ips[] = {
[ASPEED_IP_SCU] = "SCU",
[ASPEED_IP_GFX] = "GFX",
[ASPEED_IP_LPC] = "LPC",
};
static inline void aspeed_sig_desc_print_val(
const struct aspeed_sig_desc *desc, bool enable, u32 rv)
{
pr_debug("Want %s%X[0x%08X]=0x%X, got 0x%X from 0x%08X\n",
aspeed_pinmux_ips[desc->ip], desc->reg,
desc->mask, enable ? desc->enable : desc->disable,
(rv & desc->mask) >> __ffs(desc->mask), rv);
}
/**
* aspeed_sig_desc_eval() - Query the enabled or disabled state of a signal
* descriptor.
*
* @desc: The signal descriptor of interest
* @enabled: True to query the enabled state, false to query disabled state
* @map: The IP block's regmap instance
*
* Return: 1 if the descriptor's bitfield is configured to the state
* selected by @enabled, 0 if not, and less than zero if an unrecoverable
* failure occurred
*
* Evaluation of descriptor state is non-trivial in that it is not a binary
* outcome: The bitfields can be greater than one bit in size and thus can take
* a value that is neither the enabled nor disabled state recorded in the
* descriptor (typically this means a different function to the one of interest
* is enabled). Thus we must explicitly test for either condition as required.
*/
int aspeed_sig_desc_eval(const struct aspeed_sig_desc *desc,
bool enabled, struct regmap *map)
{
int ret;
unsigned int raw;
u32 want;
if (!map)
return -ENODEV;
ret = regmap_read(map, desc->reg, &raw);
if (ret)
return ret;
aspeed_sig_desc_print_val(desc, enabled, raw);
want = enabled ? desc->enable : desc->disable;
return ((raw & desc->mask) >> __ffs(desc->mask)) == want;
}
/**
* aspeed_sig_expr_eval - Query the enabled or disabled state for a
* mux function's signal on a pin
*
* @ctx: The driver context for the pinctrl IP
* @expr: An expression controlling the signal for a mux function on a pin
* @enabled: True to query the enabled state, false to query disabled state
*
* Return: 1 if the expression composed by @enabled evaluates true, 0 if not,
* and less than zero if an unrecoverable failure occurred.
*
* A mux function is enabled or disabled if the function's signal expression
* for each pin in the function's pin group evaluates true for the desired
* state. An signal expression evaluates true if all of its associated signal
* descriptors evaluate true for the desired state.
*
* If an expression's state is described by more than one bit, either through
* multi-bit bitfields in a single signal descriptor or through multiple signal
* descriptors of a single bit then it is possible for the expression to be in
* neither the enabled nor disabled state. Thus we must explicitly test for
* either condition as required.
*/
int aspeed_sig_expr_eval(struct aspeed_pinmux_data *ctx,
const struct aspeed_sig_expr *expr, bool enabled)
{
int ret;
int i;
if (ctx->ops->eval)
return ctx->ops->eval(ctx, expr, enabled);
for (i = 0; i < expr->ndescs; i++) {
const struct aspeed_sig_desc *desc = &expr->descs[i];
ret = aspeed_sig_desc_eval(desc, enabled, ctx->maps[desc->ip]);
if (ret <= 0)
return ret;
}
return 1;
}
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