Commit 882a8bb0 authored by Lad Prabhakar's avatar Lad Prabhakar Committed by Jakub Kicinski
Browse files

net: pcs: rzn1-miic: Add support to handle resets 



Add reset-line handling to the RZN1 MIIC driver and move reset
configuration into the SoC/OF data. Introduce MIIC_MAX_NUM_RSTS (= 2),
add storage for reset_control_bulk_data in struct miic and add
reset_ids and reset_count fields to miic_of_data.

When reset_ids are present in the OF data, the driver obtains the reset
lines with devm_reset_control_bulk_get_exclusive(), deasserts them during
probe and registers a devres action to assert them on remove or on error.

This change is preparatory work to support the RZ/T2H SoC, which exposes
two reset lines for the ETHSS IP. The driver remains backward compatible
for platforms that do not provide reset lines.

Signed-off-by: default avatarLad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Tested-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://patch.msgid.link/20250910204132.319975-8-prabhakar.mahadev-lad.rj@bp.renesas.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 6245237a

drivers/net/pcs/pcs-rzn1-miic.c

+56 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#include <linux/bitops.h>

#include <linux/clk.h>

#include <linux/device.h>

#include <linux/device/devres.h>

#include <linux/mdio.h>

#include <linux/of.h>

#include <linux/of_platform.h>
@@ -17,6 +18,7 @@ 
#include <linux/phylink.h>

#include <linux/platform_device.h>

#include <linux/pm_runtime.h>

#include <linux/reset.h>

#include <linux/slab.h>

#include <dt-bindings/net/pcs-rzn1-miic.h>
@@ -52,6 +54,8 @@ 
#define MIIC_MODCTRL_CONF_CONV_MAX	6

#define MIIC_MODCTRL_CONF_NONE		-1



#define MIIC_MAX_NUM_RSTS		2



/**

 * struct modctrl_match - Matching table entry for  convctrl configuration

 *			  See section 8.2.1 of manual.
@@ -126,12 +130,14 @@ static const char * const index_to_string[] = { 
 * @base: base address of the MII converter

 * @dev: Device associated to the MII converter

 * @lock: Lock used for read-modify-write access

 * @rsts: Reset controls for the MII converter

 * @of_data: Pointer to OF data

 */

struct miic {

	void __iomem *base;

	struct device *dev;

	spinlock_t lock;

	struct reset_control_bulk_data rsts[MIIC_MAX_NUM_RSTS];

	const struct miic_of_data *of_data;

};
@@ -147,6 +153,8 @@ struct miic { 
 * @miic_port_start: MIIC port start number

 * @miic_port_max: Maximum MIIC supported

 * @sw_mode_mask: Switch mode mask

 * @reset_ids: Reset names array

 * @reset_count: Number of entries in the reset_ids array

 */

struct miic_of_data {

	struct modctrl_match *match_table;
@@ -159,6 +167,8 @@ struct miic_of_data { 
	u8 miic_port_start;

	u8 miic_port_max;

	u8 sw_mode_mask;

	const char * const *reset_ids;

	u8 reset_count;

};



/**
@@ -523,6 +533,48 @@ static int miic_parse_dt(struct miic *miic, u32 *mode_cfg) 
	return ret;

}



static void miic_reset_control_bulk_assert(void *data)

{

	struct miic *miic = data;

	int ret;



	ret = reset_control_bulk_assert(miic->of_data->reset_count, miic->rsts);

	if (ret)

		dev_err(miic->dev, "failed to assert reset lines\n");

}



static int miic_reset_control_init(struct miic *miic)

{

	const struct miic_of_data *of_data = miic->of_data;

	struct device *dev = miic->dev;

	int ret;

	u8 i;



	if (!of_data->reset_count)

		return 0;



	for (i = 0; i < of_data->reset_count; i++)

		miic->rsts[i].id = of_data->reset_ids[i];



	ret = devm_reset_control_bulk_get_exclusive(dev, of_data->reset_count,

						    miic->rsts);

	if (ret)

		return dev_err_probe(dev, ret,

				     "failed to get bulk reset lines\n");



	ret = reset_control_bulk_deassert(of_data->reset_count, miic->rsts);

	if (ret)

		return dev_err_probe(dev, ret,

				     "failed to deassert reset lines\n");



	ret = devm_add_action_or_reset(dev, miic_reset_control_bulk_assert,

				       miic);

	if (ret)

		return dev_err_probe(dev, ret, "failed to add reset action\n");



	return 0;

}



static int miic_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;
@@ -546,6 +598,10 @@ static int miic_probe(struct platform_device *pdev) 
	if (IS_ERR(miic->base))

		return PTR_ERR(miic->base);



	ret = miic_reset_control_init(miic);

	if (ret)

		return ret;



	ret = devm_pm_runtime_enable(dev);

	if (ret < 0)

		return ret;