u-boot/drivers/pinctrl/pinctrl-sti.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Pinctrl driver for STMicroelectronics STi SoCs
*
* Copyright (C) 2017, STMicroelectronics - All Rights Reserved
* Author(s): Patrice Chotard, <patrice.chotard@foss.st.com> for STMicroelectronics.
*/
#include <common.h>
#include <bitfield.h>
#include <dm.h>
#include <errno.h>
#include <regmap.h>
#include <syscon.h>
#include <asm/io.h>
#include <dm/pinctrl.h>
#include <linux/bug.h>
#include <linux/libfdt.h>
DECLARE_GLOBAL_DATA_PTR;
#define MAX_STI_PINCONF_ENTRIES 7
/* Output enable */
#define OE (1 << 27)
/* Pull Up */
#define PU (1 << 26)
/* Open Drain */
#define OD (1 << 25)
/* User-frendly defines for Pin Direction */
/* oe = 0, pu = 0, od = 0 */
#define IN (0)
/* oe = 0, pu = 1, od = 0 */
#define IN_PU (PU)
/* oe = 1, pu = 0, od = 0 */
#define OUT (OE)
/* oe = 1, pu = 1, od = 0 */
#define OUT_PU (OE | PU)
/* oe = 1, pu = 0, od = 1 */
#define BIDIR (OE | OD)
/* oe = 1, pu = 1, od = 1 */
#define BIDIR_PU (OE | PU | OD)
struct sti_pinctrl_plat {
struct regmap *regmap;
};
struct sti_pin_desc {
unsigned char bank;
unsigned char pin;
unsigned char alt;
int dir;
};
/*
* PIO alternative Function selector
*/
void sti_alternate_select(struct udevice *dev, struct sti_pin_desc *pin_desc)
{
struct sti_pinctrl_plat *plat = dev_get_plat(dev);
unsigned long sysconf, *sysconfreg;
int alt = pin_desc->alt;
int bank = pin_desc->bank;
int pin = pin_desc->pin;
sysconfreg = (unsigned long *)plat->regmap->ranges[0].start;
switch (bank) {
case 0 ... 5: /* in "SBC Bank" */
sysconfreg += bank;
break;
case 10 ... 20: /* in "FRONT Bank" */
sysconfreg += bank - 10;
break;
case 30 ... 35: /* in "REAR Bank" */
sysconfreg += bank - 30;
break;
case 40 ... 42: /* in "FLASH Bank" */
sysconfreg += bank - 40;
break;
default:
BUG();
return;
}
sysconf = readl(sysconfreg);
sysconf = bitfield_replace(sysconf, pin * 4, 3, alt);
writel(sysconf, sysconfreg);
}
/* pin configuration */
void sti_pin_configure(struct udevice *dev, struct sti_pin_desc *pin_desc)
{
struct sti_pinctrl_plat *plat = dev_get_plat(dev);
int bit;
int oe = 0, pu = 0, od = 0;
unsigned long *sysconfreg;
int bank = pin_desc->bank;
sysconfreg = (unsigned long *)plat->regmap->ranges[0].start + 40;
/*
* NOTE: The PIO configuration for the PIO pins in the
* "FLASH Bank" are different from all the other banks!
* Specifically, the output-enable pin control register
* (SYS_CFG_3040) and the pull-up pin control register
* (SYS_CFG_3050), are both classed as being "reserved".
* Hence, we do not write to these registers to configure
* the OE and PU features for PIOs in this bank. However,
* the open-drain pin control register (SYS_CFG_3060)
* follows the style of the other banks, and so we can
* treat that register normally.
*
* Being pedantic, we should configure the PU and PD features
* in the "FLASH Bank" explicitly instead using the four
* SYS_CFG registers: 3080, 3081, 3085, and 3086. However, this
* would necessitate passing in the alternate function number
* to this function, and adding some horrible complexity here.
* Alternatively, we could just perform 4 32-bit "pokes" to
* these four SYS_CFG registers early in the initialization.
* In practice, these four SYS_CFG registers are correct
* after a reset, and U-Boot does not need to change them, so
* we (cheat and) rely on these registers being correct.
* WARNING: Please be aware of this (pragmatic) behaviour!
*/
int flashss = 0; /* bool: PIO in the Flash Sub-System ? */
switch (pin_desc->dir) {
case IN:
oe = 0; pu = 0; od = 0;
break;
case IN_PU:
oe = 0; pu = 1; od = 0;
break;
case OUT:
oe = 1; pu = 0; od = 0;
break;
case BIDIR:
oe = 1; pu = 0; od = 1;
break;
case BIDIR_PU:
oe = 1; pu = 1; od = 1;
break;
default:
pr_err("%s invalid direction value: 0x%x\n",
__func__, pin_desc->dir);
BUG();
break;
}
switch (bank) {
case 0 ... 5: /* in "SBC Bank" */
sysconfreg += bank / 4;
break;
case 10 ... 20: /* in "FRONT Bank" */
bank -= 10;
sysconfreg += bank / 4;
break;
case 30 ... 35: /* in "REAR Bank" */
bank -= 30;
sysconfreg += bank / 4;
break;
case 40 ... 42: /* in "FLASH Bank" */
bank -= 40;
sysconfreg += bank / 4;
flashss = 1; /* pin is in the Flash Sub-System */
break;
default:
BUG();
return;
}
bit = ((bank * 8) + pin_desc->pin) % 32;
/*
* set the "Output Enable" pin control
* but, do nothing if in the flashSS
*/
if (!flashss) {
if (oe)
generic_set_bit(bit, sysconfreg);
else
generic_clear_bit(bit, sysconfreg);
}
sysconfreg += 10; /* skip to next set of syscfg registers */
/*
* set the "Pull Up" pin control
* but, do nothing if in the FlashSS
*/
if (!flashss) {
if (pu)
generic_set_bit(bit, sysconfreg);
else
generic_clear_bit(bit, sysconfreg);
}
sysconfreg += 10; /* skip to next set of syscfg registers */
/* set the "Open Drain Enable" pin control */
if (od)
generic_set_bit(bit, sysconfreg);
else
generic_clear_bit(bit, sysconfreg);
}
static int sti_pinctrl_set_state(struct udevice *dev, struct udevice *config)
{
struct fdtdec_phandle_args args;
const void *blob = gd->fdt_blob;
const char *prop_name;
int node = dev_of_offset(config);
int property_offset, prop_len;
int pinconf_node, ret, count;
const char *bank_name;
u32 cells[MAX_STI_PINCONF_ENTRIES];
struct sti_pin_desc pin_desc;
/* go to next node "st,pins" which contains the pins configuration */
pinconf_node = fdt_subnode_offset(blob, node, "st,pins");
/*
* parse each pins configuration which looks like :
* pin_name = <bank_phandle pin_nb alt dir rt_type rt_delay rt_clk>
*/
fdt_for_each_property_offset(property_offset, blob, pinconf_node) {
fdt_getprop_by_offset(blob, property_offset, &prop_name,
&prop_len);
/* extract the bank of the pin description */
ret = fdtdec_parse_phandle_with_args(blob, pinconf_node,
prop_name, "#gpio-cells",
0, 0, &args);
if (ret < 0) {
pr_err("Can't get the gpio bank phandle: %d\n", ret);
return ret;
}
bank_name = fdt_getprop(blob, args.node, "st,bank-name",
&count);
if (count < 0) {
pr_err("Can't find bank-name property %d\n", count);
return -EINVAL;
}
pin_desc.bank = trailing_strtoln(bank_name, NULL);
count = fdtdec_get_int_array_count(blob, pinconf_node,
prop_name, cells,
ARRAY_SIZE(cells));
if (count < 0) {
pr_err("Bad pin configuration array %d\n", count);
return -EINVAL;
}
if (count > MAX_STI_PINCONF_ENTRIES) {
pr_err("Unsupported pinconf array count %d\n", count);
return -EINVAL;
}
pin_desc.pin = cells[1];
pin_desc.alt = cells[2];
pin_desc.dir = cells[3];
sti_alternate_select(dev, &pin_desc);
sti_pin_configure(dev, &pin_desc);
};
return 0;
}
static int sti_pinctrl_probe(struct udevice *dev)
{
struct sti_pinctrl_plat *plat = dev_get_plat(dev);
struct udevice *syscon;
int err;
/* get corresponding syscon phandle */
err = uclass_get_device_by_phandle(UCLASS_SYSCON, dev,
"st,syscfg", &syscon);
if (err) {
pr_err("unable to find syscon device\n");
return err;
}
plat->regmap = syscon_get_regmap(syscon);
if (!plat->regmap) {
pr_err("unable to find regmap\n");
return -ENODEV;
}
return 0;
}
static const struct udevice_id sti_pinctrl_ids[] = {
{ .compatible = "st,stih407-sbc-pinctrl" },
{ .compatible = "st,stih407-front-pinctrl" },
{ .compatible = "st,stih407-rear-pinctrl" },
{ .compatible = "st,stih407-flash-pinctrl" },
{ }
};
const struct pinctrl_ops sti_pinctrl_ops = {
.set_state = sti_pinctrl_set_state,
};
U_BOOT_DRIVER(pinctrl_sti) = {
.name = "pinctrl_sti",
.id = UCLASS_PINCTRL,
.of_match = sti_pinctrl_ids,
.ops = &sti_pinctrl_ops,
.probe = sti_pinctrl_probe,
.plat_auto = sizeof(struct sti_pinctrl_plat),
.ops = &sti_pinctrl_ops,
};