pinctrl: Add core support for Aspeed SoCs (4d3d0e42) · Commits · e / devices / android_kernel_teracube_mt6765

drivers/pinctrl/Kconfig

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		@@ -254,6 +254,7 @@ config PINCTRL_ZYNQ
		help
		This selects the pinctrl driver for Xilinx Zynq.

		source "drivers/pinctrl/aspeed/Kconfig"
		source "drivers/pinctrl/bcm/Kconfig"
		source "drivers/pinctrl/berlin/Kconfig"
		source "drivers/pinctrl/freescale/Kconfig"

drivers/pinctrl/Makefile

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		@@ -37,6 +37,7 @@ obj-$(CONFIG_PINCTRL_TB10X) += pinctrl-tb10x.o
		obj-$(CONFIG_PINCTRL_ST) += pinctrl-st.o
		obj-$(CONFIG_PINCTRL_ZYNQ) += pinctrl-zynq.o

		obj-$(CONFIG_ARCH_ASPEED) += aspeed/
		obj-y += bcm/
		obj-$(CONFIG_PINCTRL_BERLIN) += berlin/
		obj-y += freescale/

drivers/pinctrl/aspeed/Kconfig

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		config PINCTRL_ASPEED
		bool
		depends on (ARCH_ASPEED \|\| COMPILE_TEST) && OF
		depends on MFD_SYSCON
		select PINMUX
		select PINCONF
		select GENERIC_PINCONF
		select REGMAP_MMIO

drivers/pinctrl/aspeed/Makefile

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		# Aspeed pinctrl support

		ccflags-y += -Woverride-init
		obj-$(CONFIG_PINCTRL_ASPEED) += pinctrl-aspeed.o

drivers/pinctrl/aspeed/pinctrl-aspeed.c

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		/*
		* Copyright (C) 2016 IBM Corp.
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License as published by
		* the Free Software Foundation; either version 2 of the License, or
		* (at your option) any later version.
		*/

		#include <linux/mfd/syscon.h>
		#include <linux/platform_device.h>
		#include <linux/slab.h>
		#include <linux/string.h>
		#include "../core.h"
		#include "pinctrl-aspeed.h"

		int aspeed_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
		{
		struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);

		return pdata->ngroups;
		}

		const char aspeed_pinctrl_get_group_name(struct pinctrl_dev pctldev,
		unsigned int group)
		{
		struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);

		return pdata->groups[group].name;
		}

		int aspeed_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
		unsigned int group, const unsigned int **pins,
		unsigned int *npins)
		{
		struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);

		*pins = &pdata->groups[group].pins[0];
		*npins = pdata->groups[group].npins;

		return 0;
		}

		void aspeed_pinctrl_pin_dbg_show(struct pinctrl_dev *pctldev,
		struct seq_file *s, unsigned int offset)
		{
		seq_printf(s, " %s", dev_name(pctldev->dev));
		}

		int aspeed_pinmux_get_fn_count(struct pinctrl_dev *pctldev)
		{
		struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);

		return pdata->nfunctions;
		}

		const char aspeed_pinmux_get_fn_name(struct pinctrl_dev pctldev,
		unsigned int function)
		{
		struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);

		return pdata->functions[function].name;
		}

		int aspeed_pinmux_get_fn_groups(struct pinctrl_dev *pctldev,
		unsigned int function,
		const char * const **groups,
		unsigned int * const num_groups)
		{
		struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);

		*groups = pdata->functions[function].groups;
		*num_groups = pdata->functions[function].ngroups;

		return 0;
		}

		static inline void aspeed_sig_desc_print_val(
		const struct aspeed_sig_desc *desc, bool enable, u32 rv)
		{
		pr_debug("SCU%x[0x%08x]=0x%x, got 0x%x from 0x%08x\n", desc->reg,
		desc->mask, enable ? desc->enable : desc->disable,
		(rv & desc->mask) >> __ffs(desc->mask), rv);
		}

		/**
		* 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
		* @regmap: The SCU regmap instance
		*
		* @return True if the descriptor's bitfield is configured to the state
		* selected by @enabled, false otherwise
		*
		* 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.
		*/
		static bool aspeed_sig_desc_eval(const struct aspeed_sig_desc *desc,
		bool enabled, struct regmap *map)
		{
		unsigned int raw;
		u32 want;

		if (regmap_read(map, desc->reg, &raw) < 0)
		return false;

		aspeed_sig_desc_print_val(desc, enabled, raw);
		want = enabled ? desc->enable : desc->disable;

		return ((raw & desc->mask) >> __ffs(desc->mask)) == want;
		}

		/**
		* Query the enabled or disabled state for a mux function's signal on a pin
		*
		* @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
		* @regmap: The SCU regmap instance
		*
		* @return True if the expression composed by @enabled evaluates true, false
		* otherwise
		*
		* 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.
		*/
		static bool aspeed_sig_expr_eval(const struct aspeed_sig_expr *expr,
		bool enabled, struct regmap *map)
		{
		int i;

		for (i = 0; i < expr->ndescs; i++) {
		const struct aspeed_sig_desc *desc = &expr->descs[i];

		if (!aspeed_sig_desc_eval(desc, enabled, map))
		return false;
		}

		return true;
		}

		/**
		* Configure a pin's signal by applying an expression's descriptor state for
		* all descriptors in the expression.
		*
		* @expr: The expression associated with the function whose signal is to be
		* configured
		* @enable: true to enable an function's signal through a pin's signal
		* expression, false to disable the function's signal
		* @map: The SCU's regmap instance for pinmux register access.
		*
		* @return true if the expression is configured as requested, false otherwise
		*/
		static bool aspeed_sig_expr_set(const struct aspeed_sig_expr *expr,
		bool enable, struct regmap *map)
		{
		int i;
		bool ret;

		ret = aspeed_sig_expr_eval(expr, enable, map);
		if (ret)
		return ret;

		for (i = 0; i < expr->ndescs; i++) {
		const struct aspeed_sig_desc *desc = &expr->descs[i];
		u32 pattern = enable ? desc->enable : desc->disable;

		/*
		* Strap registers are configured in hardware or by early-boot
		* firmware. Treat them as read-only despite that we can write
		* them. This may mean that certain functions cannot be
		* deconfigured and is the reason we re-evaluate after writing
		* all descriptor bits.
		*/
		if (desc->reg == HW_STRAP1 \|\| desc->reg == HW_STRAP2)
		continue;

		ret = regmap_update_bits(map, desc->reg, desc->mask,
		pattern << __ffs(desc->mask));

		if (ret < 0)
		return false;
		}

		return aspeed_sig_expr_eval(expr, enable, map);
		}

		static bool aspeed_sig_expr_enable(const struct aspeed_sig_expr *expr,
		struct regmap *map)
		{
		return aspeed_sig_expr_set(expr, true, map);
		}

		static bool aspeed_sig_expr_disable(const struct aspeed_sig_expr *expr,
		struct regmap *map)
		{
		return aspeed_sig_expr_set(expr, false, map);
		}

		/**
		* Disable a signal on a pin by disabling all provided signal expressions.
		*
		* @exprs: The list of signal expressions (from a priority level on a pin)
		* @map: The SCU's regmap instance for pinmux register access.
		*
		* @return true if all expressions in the list are successfully disabled, false
		* otherwise
		*/
		static bool aspeed_disable_sig(const struct aspeed_sig_expr **exprs,
		struct regmap *map)
		{
		bool disabled = true;

		if (!exprs)
		return true;

		while (*exprs) {
		bool ret;

		ret = aspeed_sig_expr_disable(*exprs, map);
		disabled = disabled && ret;

		exprs++;
		}

		return disabled;
		}

		/**
		* Search for the signal expression needed to enable the pin's signal for the
		* requested function.
		*
		* @exprs: List of signal expressions (haystack)
		* @name: The name of the requested function (needle)
		*
		* @return A pointer to the signal expression whose function tag matches the
		* provided name, otherwise NULL.
		*
		*/
		static const struct aspeed_sig_expr *aspeed_find_expr_by_name(
		const struct aspeed_sig_expr *exprs, const char name)
		{
		while (*exprs) {
		if (strcmp((*exprs)->function, name) == 0)
		return *exprs;
		exprs++;
		}

		return NULL;
		}

		static char get_defined_attribute(const struct aspeed_pin_desc pdesc,
		const char (get)(
		const struct aspeed_sig_expr *))
		{
		char *found = NULL;
		size_t len = 0;
		const struct aspeed_sig_expr *prios, funcs, *expr;

		prios = pdesc->prios;

		while ((funcs = *prios)) {
		while ((expr = *funcs)) {
		const char *str = get(expr);
		size_t delta = strlen(str) + 2;
		char *expanded;

		expanded = krealloc(found, len + delta + 1, GFP_KERNEL);
		if (!expanded) {
		kfree(found);
		return expanded;
		}

		found = expanded;
		found[len] = '\0';
		len += delta;

		strcat(found, str);
		strcat(found, ", ");

		funcs++;
		}
		prios++;
		}

		if (len < 2) {
		kfree(found);
		return NULL;
		}

		found[len - 2] = '\0';

		return found;
		}

		static const char aspeed_sig_expr_function(const struct aspeed_sig_expr expr)
		{
		return expr->function;
		}

		static char get_defined_functions(const struct aspeed_pin_desc pdesc)
		{
		return get_defined_attribute(pdesc, aspeed_sig_expr_function);
		}

		static const char aspeed_sig_expr_signal(const struct aspeed_sig_expr expr)
		{
		return expr->signal;
		}

		static char get_defined_signals(const struct aspeed_pin_desc pdesc)
		{
		return get_defined_attribute(pdesc, aspeed_sig_expr_signal);
		}

		int aspeed_pinmux_set_mux(struct pinctrl_dev *pctldev, unsigned int function,
		unsigned int group)
		{
		int i;
		const struct aspeed_pinctrl_data *pdata =
		pinctrl_dev_get_drvdata(pctldev);
		const struct aspeed_pin_group *pgroup = &pdata->groups[group];
		const struct aspeed_pin_function *pfunc =
		&pdata->functions[function];

		for (i = 0; i < pgroup->npins; i++) {
		int pin = pgroup->pins[i];
		const struct aspeed_pin_desc *pdesc = pdata->pins[pin].drv_data;
		const struct aspeed_sig_expr *expr = NULL;
		const struct aspeed_sig_expr **funcs;
		const struct aspeed_sig_expr ***prios;

		if (!pdesc)
		return -EINVAL;

		prios = pdesc->prios;

		if (!prios)
		continue;

		/* Disable functions at a higher priority than that requested */
		while ((funcs = *prios)) {
		expr = aspeed_find_expr_by_name(funcs, pfunc->name);

		if (expr)
		break;

		if (!aspeed_disable_sig(funcs, pdata->map))
		return -EPERM;

		prios++;
		}

		if (!expr) {
		char *functions = get_defined_functions(pdesc);
		char *signals = get_defined_signals(pdesc);

		pr_warn("No function %s found on pin %s (%d). Found signal(s) %s for function(s) %s\n",
		pfunc->name, pdesc->name, pin, signals,
		functions);
		kfree(signals);
		kfree(functions);

		return -ENXIO;
		}

		if (!aspeed_sig_expr_enable(expr, pdata->map))
		return -EPERM;
		}

		return 0;
		}

		static bool aspeed_expr_is_gpio(const struct aspeed_sig_expr *expr)
		{
		/*
		* The signal type is GPIO if the signal name has "GPIO" as a prefix.
		* strncmp (rather than strcmp) is used to implement the prefix
		* requirement.
		*
		* expr->signal might look like "GPIOT3" in the GPIO case.
		*/
		return strncmp(expr->signal, "GPIO", 4) == 0;
		}

		static bool aspeed_gpio_in_exprs(const struct aspeed_sig_expr **exprs)
		{
		if (!exprs)
		return false;

		while (*exprs) {
		if (aspeed_expr_is_gpio(*exprs))
		return true;
		exprs++;
		}

		return false;
		}

		int aspeed_gpio_request_enable(struct pinctrl_dev *pctldev,
		struct pinctrl_gpio_range *range,
		unsigned int offset)
		{
		const struct aspeed_pinctrl_data *pdata =
		pinctrl_dev_get_drvdata(pctldev);
		const struct aspeed_pin_desc *pdesc = pdata->pins[offset].drv_data;
		const struct aspeed_sig_expr *prios, funcs, *expr;

		if (!pdesc)
		return -EINVAL;

		prios = pdesc->prios;

		if (!prios)
		return -ENXIO;

		/* Disable any functions of higher priority than GPIO */
		while ((funcs = *prios)) {
		if (aspeed_gpio_in_exprs(funcs))
		break;

		if (!aspeed_disable_sig(funcs, pdata->map))
		return -EPERM;

		prios++;
		}

		if (!funcs) {
		char *signals = get_defined_signals(pdesc);

		pr_warn("No GPIO signal type found on pin %s (%d). Found: %s\n",
		pdesc->name, offset, signals);
		kfree(signals);

		return -ENXIO;
		}

		expr = *funcs;

		/*
		* Disabling all higher-priority expressions is enough to enable the
		* lowest-priority signal type. As such it has no associated
		* expression.
		*/
		if (!expr)
		return 0;

		/*
		* If GPIO is not the lowest priority signal type, assume there is only
		* one expression defined to enable the GPIO function
		*/
		if (!aspeed_sig_expr_enable(expr, pdata->map))
		return -EPERM;

		return 0;
		}

		int aspeed_pinctrl_probe(struct platform_device *pdev,
		struct pinctrl_desc *pdesc,
		struct aspeed_pinctrl_data *pdata)
		{
		struct device *parent;
		struct pinctrl_dev *pctl;

		parent = pdev->dev.parent;
		if (!parent) {
		dev_err(&pdev->dev, "No parent for syscon pincontroller\n");
		return -ENODEV;
		}

		pdata->map = syscon_node_to_regmap(parent->of_node);
		if (IS_ERR(pdata->map)) {
		dev_err(&pdev->dev, "No regmap for syscon pincontroller parent\n");
		return PTR_ERR(pdata->map);
		}

		pctl = pinctrl_register(pdesc, &pdev->dev, pdata);

		if (IS_ERR(pctl)) {
		dev_err(&pdev->dev, "Failed to register pinctrl\n");
		return PTR_ERR(pctl);
		}

		platform_set_drvdata(pdev, pdata);

		return 0;
		}