Unverified Commit a085a31a authored by Maciej Purski's avatar Maciej Purski Committed by Mark Brown
Browse files

regulator: core: Parse coupled regulators properties 



On Odroid XU3/4 and other Exynos5422 based boards there is a case, that
different devices on the board are supplied by different regulators
with non-fixed voltages. If one of these devices temporarily requires
higher voltage, there might occur a situation that the spread between
devices' voltages is so high, that there is a risk of changing
'high' and 'low' states on the interconnection between devices powered
by those regulators.

Add new structure "coupling_desc" to regulator_dev, which contains
pointers to all coupled regulators including the owner of the structure,
number of coupled regulators and counter of currently resolved
regulators.

Add of_functions to parse all data needed in regulator coupling.
Provide method to check DTS data consistency. Check if each coupled
regulator's max_spread is equal and if their lists of regulators match.

Signed-off-by: default avatarMaciej Purski <m.purski@samsung.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent f98618b3

drivers/regulator/internal.h

+26 −2
Original line number Diff line number Diff line
@@ -62,6 +62,14 @@ struct regulator_init_data *regulator_of_get_init_data(struct device *dev, 
			         const struct regulator_desc *desc,

				 struct regulator_config *config,

				 struct device_node **node);



struct regulator_dev *of_parse_coupled_regulator(struct regulator_dev *rdev,

						 int index);



int of_get_n_coupled(struct regulator_dev *rdev);



bool of_check_coupling_data(struct regulator_dev *rdev);



#else

static inline struct regulator_dev *

of_find_regulator_by_node(struct device_node *np)
@@ -77,8 +85,25 @@ regulator_of_get_init_data(struct device *dev, 
{

	return NULL;

}

#endif



static inline struct regulator_dev *

of_parse_coupled_regulator(struct regulator_dev *rdev,

			   int index)

{

	return NULL;

}



static inline int of_get_n_coupled(struct regulator_dev *rdev)

{

	return 0;

}



static inline bool of_check_coupling_data(struct regulator_dev *rdev)

{

	return false;

}



#endif

enum regulator_get_type {

	NORMAL_GET,

	EXCLUSIVE_GET,
@@ -88,5 +113,4 @@ enum regulator_get_type { 


struct regulator *_regulator_get(struct device *dev, const char *id,

				 enum regulator_get_type get_type);



#endif

drivers/regulator/of_regulator.c

+151 −0
Original line number Diff line number Diff line
@@ -166,6 +166,10 @@ static void of_get_regulation_constraints(struct device_node *np, 
	if (!of_property_read_u32(np, "regulator-system-load", &pval))

		constraints->system_load = pval;



	if (!of_property_read_u32(np, "regulator-coupled-max-spread",

				  &pval))

		constraints->max_spread = pval;



	constraints->over_current_protection = of_property_read_bool(np,

					"regulator-over-current-protection");
@@ -435,3 +439,150 @@ struct regulator_dev *of_find_regulator_by_node(struct device_node *np) 


	return dev ? dev_to_rdev(dev) : NULL;

}



/*

 * Returns number of regulators coupled with rdev.

 */

int of_get_n_coupled(struct regulator_dev *rdev)

{

	struct device_node *node = rdev->dev.of_node;

	int n_phandles;



	n_phandles = of_count_phandle_with_args(node,

						"regulator-coupled-with",

						NULL);



	return (n_phandles > 0) ? n_phandles : 0;

}



/* Looks for "to_find" device_node in src's "regulator-coupled-with" property */

static bool of_coupling_find_node(struct device_node *src,

				  struct device_node *to_find)

{

	int n_phandles, i;

	bool found = false;



	n_phandles = of_count_phandle_with_args(src,

						"regulator-coupled-with",

						NULL);



	for (i = 0; i < n_phandles; i++) {

		struct device_node *tmp = of_parse_phandle(src,

					   "regulator-coupled-with", i);



		if (!tmp)

			break;



		/* found */

		if (tmp == to_find)

			found = true;



		of_node_put(tmp);



		if (found)

			break;

	}



	return found;

}



/**

 * of_check_coupling_data - Parse rdev's coupling properties and check data

 *			    consistency

 * @rdev - pointer to regulator_dev whose data is checked

 *

 * Function checks if all the following conditions are met:

 * - rdev's max_spread is greater than 0

 * - all coupled regulators have the same max_spread

 * - all coupled regulators have the same number of regulator_dev phandles

 * - all regulators are linked to each other

 *

 * Returns true if all conditions are met.

 */

bool of_check_coupling_data(struct regulator_dev *rdev)

{

	int max_spread = rdev->constraints->max_spread;

	struct device_node *node = rdev->dev.of_node;

	int n_phandles = of_get_n_coupled(rdev);

	struct device_node *c_node;

	int i;

	bool ret = true;



	if (max_spread <= 0) {

		dev_err(&rdev->dev, "max_spread value invalid\n");

		return false;

	}



	/* iterate over rdev's phandles */

	for (i = 0; i < n_phandles; i++) {

		int c_max_spread, c_n_phandles;



		c_node = of_parse_phandle(node,

					  "regulator-coupled-with", i);



		if (!c_node)

			ret = false;



		c_n_phandles = of_count_phandle_with_args(c_node,

							  "regulator-coupled-with",

							  NULL);



		if (c_n_phandles != n_phandles) {

			dev_err(&rdev->dev, "number of couped reg phandles mismatch\n");

			ret = false;

			goto clean;

		}



		if (of_property_read_u32(c_node, "regulator-coupled-max-spread",

					 &c_max_spread)) {

			ret = false;

			goto clean;

		}



		if (c_max_spread != max_spread) {

			dev_err(&rdev->dev,

				"coupled regulators max_spread mismatch\n");

			ret = false;

			goto clean;

		}



		if (!of_coupling_find_node(c_node, node)) {

			dev_err(&rdev->dev, "missing 2-way linking for coupled regulators\n");

			ret = false;

		}



clean:

		of_node_put(c_node);

		if (!ret)

			break;

	}



	return ret;

}



/**

 * of_parse_coupled regulator - Get regulator_dev pointer from rdev's property

 * @rdev: Pointer to regulator_dev, whose DTS is used as a source to parse

 *	  "regulator-coupled-with" property

 * @index: Index in phandles array

 *

 * Returns the regulator_dev pointer parsed from DTS. If it has not been yet

 * registered, returns NULL

 */

struct regulator_dev *of_parse_coupled_regulator(struct regulator_dev *rdev,

						 int index)

{

	struct device_node *node = rdev->dev.of_node;

	struct device_node *c_node;

	struct regulator_dev *c_rdev;



	c_node = of_parse_phandle(node, "regulator-coupled-with", index);

	if (!c_node)

		return NULL;



	c_rdev = of_find_regulator_by_node(c_node);



	of_node_put(c_node);



	return c_rdev;

}

include/linux/regulator/driver.h

+18 −0
Original line number Diff line number Diff line
@@ -15,6 +15,8 @@ 
#ifndef __LINUX_REGULATOR_DRIVER_H_

#define __LINUX_REGULATOR_DRIVER_H_



#define MAX_COUPLED		4



#include <linux/device.h>

#include <linux/notifier.h>

#include <linux/regulator/consumer.h>
@@ -409,6 +411,20 @@ struct regulator_config { 
	unsigned int ena_gpio_flags;

};



/*

 * struct coupling_desc

 *

 * Describes coupling of regulators. Each regulator should have

 * at least a pointer to itself in coupled_rdevs array.

 * When a new coupled regulator is resolved, n_resolved is

 * incremented.

 */

struct coupling_desc {

	struct regulator_dev *coupled_rdevs[MAX_COUPLED];

	int n_resolved;

	int n_coupled;

};



/*

 * struct regulator_dev

 *
@@ -432,6 +448,8 @@ struct regulator_dev { 
	/* lists we own */

	struct list_head consumer_list; /* consumers we supply */



	struct coupling_desc coupling_desc;



	struct blocking_notifier_head notifier;

	struct mutex mutex; /* consumer lock */

	struct task_struct *mutex_owner;

include/linux/regulator/machine.h

+4 −0
Original line number Diff line number Diff line
@@ -103,6 +103,7 @@ struct regulator_state { 
 * @ilim_uA: Maximum input current.

 * @system_load: Load that isn't captured by any consumer requests.

 *

 * @max_spread: Max possible spread between coupled regulators

 * @valid_modes_mask: Mask of modes which may be configured by consumers.

 * @valid_ops_mask: Operations which may be performed by consumers.

 *
@@ -154,6 +155,9 @@ struct regulation_constraints { 


	int system_load;



	/* used for coupled regulators */

	int max_spread;



	/* valid regulator operating modes for this machine */

	unsigned int valid_modes_mask;

CRA Git | Maintained and supported by SUSTech CRA and CCSE