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      1 // SPDX-License-Identifier: GPL-2.0+
      2 /*
      3  * Pinctrl driver for STMicroelectronics STi SoCs
      4  *
      5  * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
      6  * Author(s): Patrice Chotard, <patrice.chotard (at) st.com> for STMicroelectronics.
      7  */
      8 
      9 #include <common.h>
     10 #include <bitfield.h>
     11 #include <dm.h>
     12 #include <errno.h>
     13 #include <regmap.h>
     14 #include <syscon.h>
     15 #include <asm/io.h>
     16 #include <dm/pinctrl.h>
     17 
     18 DECLARE_GLOBAL_DATA_PTR;
     19 
     20 #define MAX_STI_PINCONF_ENTRIES		7
     21 /* Output enable */
     22 #define OE			(1 << 27)
     23 /* Pull Up */
     24 #define PU			(1 << 26)
     25 /* Open Drain */
     26 #define OD			(1 << 25)
     27 
     28 /* User-frendly defines for Pin Direction */
     29 		/* oe = 0, pu = 0, od = 0 */
     30 #define IN			(0)
     31 		/* oe = 0, pu = 1, od = 0 */
     32 #define IN_PU			(PU)
     33 		/* oe = 1, pu = 0, od = 0 */
     34 #define OUT			(OE)
     35 		/* oe = 1, pu = 1, od = 0 */
     36 #define OUT_PU			(OE | PU)
     37 		/* oe = 1, pu = 0, od = 1 */
     38 #define BIDIR			(OE | OD)
     39 		/* oe = 1, pu = 1, od = 1 */
     40 #define BIDIR_PU		(OE | PU | OD)
     41 
     42 struct sti_pinctrl_platdata {
     43 	struct regmap *regmap;
     44 };
     45 
     46 struct sti_pin_desc {
     47 	unsigned char bank;
     48 	unsigned char pin;
     49 	unsigned char alt;
     50 	int dir;
     51 };
     52 
     53 /*
     54  * PIO alternative Function selector
     55  */
     56 void sti_alternate_select(struct udevice *dev, struct sti_pin_desc *pin_desc)
     57 {
     58 	struct sti_pinctrl_platdata *plat = dev_get_platdata(dev);
     59 	unsigned long sysconf, *sysconfreg;
     60 	int alt = pin_desc->alt;
     61 	int bank = pin_desc->bank;
     62 	int pin = pin_desc->pin;
     63 
     64 	sysconfreg = (unsigned long *)plat->regmap->ranges[0].start;
     65 
     66 	switch (bank) {
     67 	case 0 ... 5:		/* in "SBC Bank" */
     68 		sysconfreg += bank;
     69 		break;
     70 	case 10 ... 20:		/* in "FRONT Bank" */
     71 		sysconfreg += bank - 10;
     72 		break;
     73 	case 30 ... 35:		/* in "REAR Bank" */
     74 		sysconfreg += bank - 30;
     75 		break;
     76 	case 40 ... 42:		/* in "FLASH Bank" */
     77 		sysconfreg += bank - 40;
     78 		break;
     79 	default:
     80 		BUG();
     81 		return;
     82 	}
     83 
     84 	sysconf = readl(sysconfreg);
     85 	sysconf = bitfield_replace(sysconf, pin * 4, 3, alt);
     86 	writel(sysconf, sysconfreg);
     87 }
     88 
     89 /* pin configuration */
     90 void sti_pin_configure(struct udevice *dev, struct sti_pin_desc *pin_desc)
     91 {
     92 	struct sti_pinctrl_platdata *plat = dev_get_platdata(dev);
     93 	int bit;
     94 	int oe = 0, pu = 0, od = 0;
     95 	unsigned long *sysconfreg;
     96 	int bank = pin_desc->bank;
     97 
     98 	sysconfreg = (unsigned long *)plat->regmap->ranges[0].start + 40;
     99 
    100 	/*
    101 	 * NOTE: The PIO configuration for the PIO pins in the
    102 	 * "FLASH Bank" are different from all the other banks!
    103 	 * Specifically, the output-enable pin control register
    104 	 * (SYS_CFG_3040) and the pull-up pin control register
    105 	 * (SYS_CFG_3050), are both classed as being "reserved".
    106 	 * Hence, we do not write to these registers to configure
    107 	 * the OE and PU features for PIOs in this bank. However,
    108 	 * the open-drain pin control register (SYS_CFG_3060)
    109 	 * follows the style of the other banks, and so we can
    110 	 * treat that register normally.
    111 	 *
    112 	 * Being pedantic, we should configure the PU and PD features
    113 	 * in the "FLASH Bank" explicitly instead using the four
    114 	 * SYS_CFG registers: 3080, 3081, 3085, and 3086. However, this
    115 	 * would necessitate passing in the alternate function number
    116 	 * to this function, and adding some horrible complexity here.
    117 	 * Alternatively, we could just perform 4 32-bit "pokes" to
    118 	 * these four SYS_CFG registers early in the initialization.
    119 	 * In practice, these four SYS_CFG registers are correct
    120 	 * after a reset, and U-Boot does not need to change them, so
    121 	 * we (cheat and) rely on these registers being correct.
    122 	 * WARNING: Please be aware of this (pragmatic) behaviour!
    123 	 */
    124 	int flashss = 0;	/* bool: PIO in the Flash Sub-System ? */
    125 
    126 	switch (pin_desc->dir) {
    127 	case IN:
    128 		oe = 0; pu = 0; od = 0;
    129 		break;
    130 	case IN_PU:
    131 		oe = 0; pu = 1; od = 0;
    132 		break;
    133 	case OUT:
    134 		oe = 1; pu = 0; od = 0;
    135 		break;
    136 	case BIDIR:
    137 		oe = 1; pu = 0; od = 1;
    138 		break;
    139 	case BIDIR_PU:
    140 		oe = 1; pu = 1; od = 1;
    141 		break;
    142 
    143 	default:
    144 		pr_err("%s invalid direction value: 0x%x\n",
    145 		      __func__, pin_desc->dir);
    146 		BUG();
    147 		break;
    148 	}
    149 
    150 	switch (bank) {
    151 	case 0 ... 5:		/* in "SBC Bank" */
    152 		sysconfreg += bank / 4;
    153 		break;
    154 	case 10 ... 20:		/* in "FRONT Bank" */
    155 		bank -= 10;
    156 		sysconfreg += bank / 4;
    157 		break;
    158 	case 30 ... 35:		/* in "REAR Bank" */
    159 		bank -= 30;
    160 		sysconfreg += bank / 4;
    161 		break;
    162 	case 40 ... 42:		/* in "FLASH Bank" */
    163 		bank -= 40;
    164 		sysconfreg += bank / 4;
    165 		flashss = 1;	/* pin is in the Flash Sub-System */
    166 		break;
    167 	default:
    168 		BUG();
    169 		return;
    170 	}
    171 
    172 	bit = ((bank * 8) + pin_desc->pin) % 32;
    173 
    174 	/*
    175 	 * set the "Output Enable" pin control
    176 	 * but, do nothing if in the flashSS
    177 	 */
    178 	if (!flashss) {
    179 		if (oe)
    180 			generic_set_bit(bit, sysconfreg);
    181 		else
    182 			generic_clear_bit(bit, sysconfreg);
    183 	}
    184 
    185 	sysconfreg += 10;	/* skip to next set of syscfg registers */
    186 
    187 	/*
    188 	 * set the "Pull Up" pin control
    189 	 * but, do nothing if in the FlashSS
    190 	 */
    191 
    192 	if (!flashss) {
    193 		if (pu)
    194 			generic_set_bit(bit, sysconfreg);
    195 		else
    196 			generic_clear_bit(bit, sysconfreg);
    197 	}
    198 
    199 	sysconfreg += 10;	/* skip to next set of syscfg registers */
    200 
    201 	/* set the "Open Drain Enable" pin control */
    202 	if (od)
    203 		generic_set_bit(bit, sysconfreg);
    204 	else
    205 		generic_clear_bit(bit, sysconfreg);
    206 }
    207 
    208 
    209 static int sti_pinctrl_set_state(struct udevice *dev, struct udevice *config)
    210 {
    211 	struct fdtdec_phandle_args args;
    212 	const void *blob = gd->fdt_blob;
    213 	const char *prop_name;
    214 	int node = dev_of_offset(config);
    215 	int property_offset, prop_len;
    216 	int pinconf_node, ret, count;
    217 	const char *bank_name;
    218 	u32 cells[MAX_STI_PINCONF_ENTRIES];
    219 
    220 	struct sti_pin_desc pin_desc;
    221 
    222 	/* go to next node "st,pins" which contains the pins configuration */
    223 	pinconf_node = fdt_subnode_offset(blob, node, "st,pins");
    224 
    225 	/*
    226 	 * parse each pins configuration which looks like :
    227 	 *	pin_name = <bank_phandle pin_nb alt dir rt_type rt_delay rt_clk>
    228 	 */
    229 
    230 	fdt_for_each_property_offset(property_offset, blob, pinconf_node) {
    231 		fdt_getprop_by_offset(blob, property_offset, &prop_name,
    232 				      &prop_len);
    233 
    234 		/* extract the bank of the pin description */
    235 		ret = fdtdec_parse_phandle_with_args(blob, pinconf_node,
    236 						     prop_name, "#gpio-cells",
    237 						     0, 0, &args);
    238 		if (ret < 0) {
    239 			pr_err("Can't get the gpio bank phandle: %d\n", ret);
    240 			return ret;
    241 		}
    242 
    243 		bank_name = fdt_getprop(blob, args.node, "st,bank-name",
    244 					&count);
    245 		if (count < 0) {
    246 			pr_err("Can't find bank-name property %d\n", count);
    247 			return -EINVAL;
    248 		}
    249 
    250 		pin_desc.bank = trailing_strtoln(bank_name, NULL);
    251 
    252 		count = fdtdec_get_int_array_count(blob, pinconf_node,
    253 						   prop_name, cells,
    254 						   ARRAY_SIZE(cells));
    255 		if (count < 0) {
    256 			pr_err("Bad pin configuration array %d\n", count);
    257 			return -EINVAL;
    258 		}
    259 
    260 		if (count > MAX_STI_PINCONF_ENTRIES) {
    261 			pr_err("Unsupported pinconf array count %d\n", count);
    262 			return -EINVAL;
    263 		}
    264 
    265 		pin_desc.pin = cells[1];
    266 		pin_desc.alt = cells[2];
    267 		pin_desc.dir = cells[3];
    268 
    269 		sti_alternate_select(dev, &pin_desc);
    270 		sti_pin_configure(dev, &pin_desc);
    271 	};
    272 
    273 	return 0;
    274 }
    275 
    276 static int sti_pinctrl_probe(struct udevice *dev)
    277 {
    278 	struct sti_pinctrl_platdata *plat = dev_get_platdata(dev);
    279 	struct udevice *syscon;
    280 	int err;
    281 
    282 	/* get corresponding syscon phandle */
    283 	err = uclass_get_device_by_phandle(UCLASS_SYSCON, dev,
    284 					   "st,syscfg", &syscon);
    285 	if (err) {
    286 		pr_err("unable to find syscon device\n");
    287 		return err;
    288 	}
    289 
    290 	plat->regmap = syscon_get_regmap(syscon);
    291 	if (!plat->regmap) {
    292 		pr_err("unable to find regmap\n");
    293 		return -ENODEV;
    294 	}
    295 
    296 	return 0;
    297 }
    298 
    299 static const struct udevice_id sti_pinctrl_ids[] = {
    300 	{ .compatible = "st,stih407-sbc-pinctrl" },
    301 	{ .compatible = "st,stih407-front-pinctrl" },
    302 	{ .compatible = "st,stih407-rear-pinctrl" },
    303 	{ .compatible = "st,stih407-flash-pinctrl" },
    304 	{ }
    305 };
    306 
    307 const struct pinctrl_ops sti_pinctrl_ops = {
    308 	.set_state = sti_pinctrl_set_state,
    309 };
    310 
    311 U_BOOT_DRIVER(pinctrl_sti) = {
    312 	.name = "pinctrl_sti",
    313 	.id = UCLASS_PINCTRL,
    314 	.of_match = sti_pinctrl_ids,
    315 	.ops = &sti_pinctrl_ops,
    316 	.probe = sti_pinctrl_probe,
    317 	.platdata_auto_alloc_size = sizeof(struct sti_pinctrl_platdata),
    318 	.ops = &sti_pinctrl_ops,
    319 };
    320