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      1 /* $NetBSD: acpi_i2c.c,v 1.23 2025/09/23 06:28:19 thorpej Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2017, 2021, 2025 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Manuel Bouyer.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include "iic.h"
     33 
     34 #include <sys/cdefs.h>
     35 __KERNEL_RCSID(0, "$NetBSD: acpi_i2c.c,v 1.23 2025/09/23 06:28:19 thorpej Exp $");
     36 
     37 #include <sys/device.h>
     38 
     39 #include <dev/acpi/acpireg.h>
     40 #include <dev/acpi/acpivar.h>
     41 #include <dev/acpi/acpi_i2c.h>
     42 #include <external/bsd/acpica/dist/include/acinterp.h>
     43 #include <external/bsd/acpica/dist/include/amlcode.h>
     44 
     45 #include <dev/i2c/i2cvar.h>
     46 #include <dev/i2c/i2c_calls.h>
     47 #include <dev/i2c/i2c_enum.h>
     48 
     49 #include <sys/kmem.h>
     50 
     51 #define _COMPONENT	ACPI_BUS_COMPONENT
     52 ACPI_MODULE_NAME	("acpi_i2c")
     53 
     54 struct acpi_i2c_address_space_context {
     55 	ACPI_CONNECTION_INFO conn_info;	/* must be first */
     56 	i2c_tag_t tag;
     57 };
     58 
     59 static const struct device_compatible_entry hid_compat_data[] = {
     60 	{ .compat = "PNP0C50" },
     61 	DEVICE_COMPAT_EOL
     62 };
     63 
     64 #if NIIC > 0
     65 struct acpi_i2c_context {
     66 	uint16_t i2c_addr;
     67 	struct acpi_devnode *res_src;
     68 };
     69 #endif
     70 
     71 static struct acpi_devnode *
     72 acpi_i2c_resource_find_source(ACPI_RESOURCE_SOURCE *rs)
     73 {
     74 	ACPI_STATUS rv;
     75 	ACPI_HANDLE hdl;
     76 	struct acpi_devnode *ad;
     77 
     78 	if (rs->StringPtr == NULL) {
     79 		return NULL;
     80 	}
     81 
     82 	rv = AcpiGetHandle(NULL, rs->StringPtr, &hdl);
     83 	if (ACPI_FAILURE(rv)) {
     84 		printf("%s: couldn't lookup '%s': %s\n", __func__,
     85 		    rs->StringPtr, AcpiFormatException(rv));
     86 		return NULL;
     87 	}
     88 
     89 	SIMPLEQ_FOREACH(ad, &acpi_softc->sc_head, ad_list) {
     90 		if (ad->ad_handle == hdl) {
     91 			return ad;
     92 		}
     93 	}
     94 
     95 	printf("%s: no acpi devnode matching resource source '%s'\n",
     96 	    __func__, rs->StringPtr);
     97 	return NULL;
     98 }
     99 
    100 static ACPI_STATUS
    101 acpi_i2c_resource_parse_callback(ACPI_RESOURCE *res, void *context)
    102 {
    103 	struct acpi_i2c_context *i2cc = context;
    104 
    105 	switch (res->Type) {
    106 	case ACPI_RESOURCE_TYPE_END_TAG:
    107 		break;
    108 	case ACPI_RESOURCE_TYPE_SERIAL_BUS:
    109 		switch (res->Data.I2cSerialBus.Type) {
    110 		case ACPI_RESOURCE_SERIAL_TYPE_I2C:
    111 			i2cc->i2c_addr = res->Data.I2cSerialBus.SlaveAddress;
    112 			i2cc->res_src = acpi_i2c_resource_find_source(
    113 			    &res->Data.I2cSerialBus.ResourceSource);
    114 			break;
    115 		}
    116 		break;
    117 	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
    118 		break;
    119 	default:
    120 		break;
    121 	}
    122 	return_ACPI_STATUS(AE_OK);
    123 }
    124 
    125 static bool
    126 acpi_i2c_enumerate_device(device_t dev, struct acpi_devnode *ad,
    127     struct i2c_enumerate_devices_args * const args)
    128 {
    129 	struct acpi_i2c_context i2cc;
    130 	ACPI_STATUS rv;
    131 	char *clist;
    132 	size_t clist_size;
    133 	bool cbrv;
    134 
    135 	memset(&i2cc, 0, sizeof(i2cc));
    136 	rv = AcpiWalkResources(ad->ad_handle, "_CRS",
    137 	     acpi_i2c_resource_parse_callback, &i2cc);
    138 	if (ACPI_FAILURE(rv)) {
    139 		aprint_error_dev(dev,
    140 		    "ACPI: unable to get resources for %s: %s\n",
    141 		    ad->ad_name, AcpiFormatException(rv));
    142 		return true;	/* keep enumerating */
    143 	}
    144 	if (i2cc.i2c_addr == 0) {
    145 		return true;	/* keep enumerating */
    146 	}
    147 
    148 	clist = acpi_pack_compat_list(ad, &clist_size);
    149 	if (clist == NULL) {
    150 		aprint_error_dev(dev,
    151 		    "ACPI: ignoring device %s (no _HID or _CID)\n",
    152 		    ad->ad_name);
    153 		return true;	/* keep enumerating */
    154 	}
    155 
    156 	cbrv = i2c_enumerate_device(dev, args, ad->ad_name,
    157 	    clist, clist_size, i2cc.i2c_addr,
    158 	    devhandle_from_acpi(device_handle(dev), ad->ad_handle));
    159 
    160 	kmem_free(clist, clist_size);
    161 
    162 	return cbrv;		/* callback decides if we keep enumerating */
    163 }
    164 
    165 static void
    166 acpi_i2c_enumerate_hid_devs(device_t dev, struct acpi_devnode *devnode,
    167     struct i2c_enumerate_devices_args * const args)
    168 {
    169 	struct acpi_devnode *ad;
    170 
    171 	KASSERT(dev != NULL);
    172 
    173 	SIMPLEQ_FOREACH(ad, &acpi_softc->sc_head, ad_list) {
    174 		struct acpi_attach_args aa = {
    175 			.aa_node = ad
    176 		};
    177 		struct acpi_i2c_context i2cc;
    178 		ACPI_STATUS rv;
    179 
    180 		if (!acpi_device_present(ad->ad_handle))
    181 			continue;
    182 		/*
    183 		 * We don't know why the caller is enumerating, so
    184 		 * in addition to checking of the node hasn't been
    185 		 * claimed, we check to see if it's been claimed by
    186 		 * ourselves already and let those through as well.
    187 		 */
    188 		if (ad->ad_device != NULL && ad->ad_device != dev)
    189 			continue;
    190 		if (acpi_compatible_match(&aa, hid_compat_data) == 0)
    191 			continue;
    192 
    193 		memset(&i2cc, 0, sizeof(i2cc));
    194 		rv = AcpiWalkResources(ad->ad_handle, "_CRS",
    195 		    acpi_i2c_resource_parse_callback, &i2cc);
    196 		if (ACPI_SUCCESS(rv) &&
    197 		    i2cc.i2c_addr != 0 &&
    198 		    i2cc.res_src == devnode) {
    199 			aprint_debug_dev(dev, "claiming %s\n", ad->ad_name);
    200 			ad->ad_device = dev;
    201 			acpi_claim_childdevs(dev, ad, NULL);
    202 			if (!acpi_i2c_enumerate_device(dev, ad, args))
    203 				break;
    204 		}
    205 	}
    206 }
    207 
    208 static int
    209 acpi_i2c_enumerate_devices(device_t dev, devhandle_t call_handle, void *v)
    210 {
    211 	struct i2c_enumerate_devices_args *args = v;
    212 	ACPI_HANDLE *hdl = devhandle_to_acpi(device_handle(dev));
    213 	struct acpi_devnode *ad, *devnode = acpi_match_node(hdl);
    214 
    215 	KASSERT(dev != NULL);
    216 
    217 	if (devnode == NULL) {
    218 		aprint_error_dev(dev, "%s: no devnode matching handle\n",
    219 		    __func__);
    220 		return 0;
    221 	}
    222 
    223 	SIMPLEQ_FOREACH(ad, &devnode->ad_child_head, ad_child_list) {
    224 		if (ad->ad_devinfo->Type != ACPI_TYPE_DEVICE)
    225 			continue;
    226 		if (!acpi_device_present(ad->ad_handle))
    227 			continue;
    228 		if (!acpi_i2c_enumerate_device(dev, ad, args))
    229 			break;
    230 	}
    231 
    232 	acpi_claim_childdevs(dev, devnode, "_CRS");
    233 	acpi_claim_childdevs(dev, devnode, "_ADR");
    234 
    235 	/*
    236 	 * I2C HID devices might not be children of the controller in the
    237 	 * ACPI device tree; go look for those separately.
    238 	 */
    239 	acpi_i2c_enumerate_hid_devs(dev, devnode, args);
    240 
    241 	return 0;
    242 }
    243 ACPI_DEVICE_CALL_REGISTER(I2C_ENUMERATE_DEVICES_STR,
    244 			  acpi_i2c_enumerate_devices)
    245 
    246 #if NIIC > 0
    247 static ACPI_STATUS
    248 acpi_i2c_gsb_init(ACPI_HANDLE region_hdl, UINT32 function,
    249     void *handler_ctx, void **region_ctx)
    250 {
    251 	if (function == ACPI_REGION_DEACTIVATE) {
    252 		*region_ctx = NULL;
    253 	} else {
    254 		*region_ctx = region_hdl;
    255 	}
    256 	return AE_OK;
    257 }
    258 
    259 static ACPI_STATUS
    260 acpi_i2c_gsb_handler(UINT32 function, ACPI_PHYSICAL_ADDRESS address,
    261     UINT32 bit_width, UINT64 *value, void *handler_ctx,
    262     void *region_ctx)
    263 {
    264 	ACPI_OPERAND_OBJECT *region_obj = region_ctx;
    265 	struct acpi_i2c_address_space_context *context = handler_ctx;
    266 	UINT8 *buf = ACPI_CAST_PTR(uint8_t, value);
    267 	ACPI_PHYSICAL_ADDRESS base_address;
    268 	ACPI_RESOURCE *res;
    269 	ACPI_STATUS rv;
    270 	ACPI_CONNECTION_INFO *conn_info = &context->conn_info;
    271 	i2c_tag_t tag = context->tag;
    272 	i2c_addr_t i2c_addr;
    273 	i2c_op_t op;
    274 	union {
    275 		uint8_t cmd8;
    276 		uint16_t cmd16;
    277 		uint32_t cmd32;
    278 	} cmd;
    279 	size_t buflen;
    280 	size_t cmdlen;
    281 	bool do_xfer = true;
    282 
    283 	if (region_obj->Region.Type != ACPI_TYPE_REGION) {
    284 		return AE_OK;
    285 	}
    286 
    287 	base_address = region_obj->Region.Address;
    288 	KASSERT(region_obj->Region.SpaceId == ACPI_ADR_SPACE_GSBUS);
    289 
    290 	rv = AcpiBufferToResource(conn_info->Connection, conn_info->Length,
    291 	    &res);
    292 	if (ACPI_FAILURE(rv)) {
    293 		return rv;
    294 	}
    295 	if (res->Type != ACPI_RESOURCE_TYPE_SERIAL_BUS ||
    296 	    res->Data.CommonSerialBus.Type != ACPI_RESOURCE_SERIAL_TYPE_I2C) {
    297 		return AE_TYPE;
    298 	}
    299 
    300 	i2c_addr = res->Data.I2cSerialBus.SlaveAddress;
    301 	if ((function & ACPI_IO_MASK) != 0) {
    302 		op = I2C_OP_WRITE_WITH_STOP;
    303 	} else {
    304 		op = I2C_OP_READ_WITH_STOP;
    305 	}
    306 
    307 #ifdef ACPI_I2C_DEBUG
    308 	UINT32 length;
    309 	rv = AcpiExGetProtocolBufferLength(function >> 16, &length);
    310 	if (ACPI_FAILURE(rv)) {
    311 		printf("%s AcpiExGetProtocolBufferLength failed: %s\n",
    312 		    __func__, AcpiFormatException(rv));
    313 		length = UINT32_MAX;
    314 	}
    315 	printf("%s %s: %s Attr %X Addr %.4X BaseAddr %.4X Length %.2X BitWidth %X BufLen %X",
    316 	       __func__, AcpiUtGetRegionName(region_obj->Region.SpaceId),
    317 	       (function & ACPI_IO_MASK) ? "Write" : "Read ",
    318 	       (UINT32) (function >> 16),
    319 	       (UINT32) address, (UINT32) base_address,
    320 	       length, bit_width, buf[1]);
    321 	printf(" [AccessLength %.2X Connection %p]\n",
    322 	       conn_info->AccessLength, conn_info->Connection);
    323 #endif
    324 
    325 	switch ((UINT32)(function >> 16)) {
    326 	case AML_FIELD_ATTRIB_QUICK:
    327 		cmdlen = 0;
    328 		buflen = 0;
    329 		break;
    330 	case AML_FIELD_ATTRIB_SEND_RECEIVE:
    331 		cmdlen = 0;
    332 		buflen = 1;
    333 		break;
    334 	case AML_FIELD_ATTRIB_BYTE:
    335 		cmdlen = bit_width / NBBY;
    336 		buflen = 1;
    337 		break;
    338 	case AML_FIELD_ATTRIB_WORD:
    339 		cmdlen = bit_width / NBBY;
    340 		buflen = 2;
    341 		break;
    342 	case AML_FIELD_ATTRIB_BYTES:
    343 		cmdlen = bit_width / NBBY;
    344 		buflen = buf[1];
    345 		break;
    346 	case AML_FIELD_ATTRIB_BLOCK:
    347 		cmdlen = bit_width / NBBY;
    348 		buflen = buf[1];
    349 		op |= I2C_OPMASK_BLKMODE;
    350 		break;
    351 	case AML_FIELD_ATTRIB_RAW_BYTES:
    352 	case AML_FIELD_ATTRIB_RAW_PROCESS_BYTES:
    353 	case AML_FIELD_ATTRIB_PROCESS_CALL:
    354 	default:
    355 		cmdlen = 0;
    356 		do_xfer = false;
    357 #ifdef ACPI_I2C_DEBUG
    358 		printf("field attrib 0x%x not supported\n",
    359 		    (UINT32)(function >> 16));
    360 #endif
    361 		break;
    362 	}
    363 
    364 	switch (cmdlen) {
    365 	case 0:
    366 	case 1:
    367 		cmd.cmd8 = (uint8_t)(base_address + address);
    368 		break;
    369 	case 2:
    370 		cmd.cmd16 = (uint16_t)(base_address + address);
    371 		break;
    372 	case 4:
    373 		cmd.cmd32 = (uint32_t)(base_address + address);
    374 		break;
    375 	default:
    376 		do_xfer = false;
    377 #ifdef ACPI_I2C_DEBUG
    378 		printf("cmdlen %zu not supported\n", cmdlen);
    379 #endif
    380 		break;
    381 	}
    382 
    383 	if (!do_xfer) {
    384 		buf[0] = EINVAL;
    385 	} else {
    386 		const int flags = I2C_F_POLL;
    387 		iic_acquire_bus(tag, flags);
    388 		buf[0] = iic_exec(tag, op, i2c_addr,
    389 				  &cmd, cmdlen, &buf[2], buflen, flags);
    390 		iic_release_bus(tag, flags);
    391 		if (buf[0] == 0) {
    392 			buf[1] = buflen;
    393 		}
    394 #ifdef ACPI_I2C_DEBUG
    395 		printf("%s iic_exec op %u addr 0x%x len %zu/%zu returned %d\n",
    396 		    __func__, op, res->Data.I2cSerialBus.SlaveAddress, cmdlen,
    397 		    buflen, buf[0]);
    398 #endif
    399 	}
    400 
    401 	ACPI_FREE(res);
    402 
    403 	return AE_OK;
    404 }
    405 #endif
    406 
    407 void
    408 acpi_i2c_register(device_t dev, i2c_tag_t tag)
    409 {
    410 #if NIIC > 0
    411 	ACPI_HANDLE hdl = devhandle_to_acpi(device_handle(dev));
    412 	struct acpi_i2c_address_space_context *context;
    413 	ACPI_STATUS rv;
    414 
    415 	context = kmem_zalloc(sizeof(*context), KM_SLEEP);
    416 	context->tag = tag;
    417 
    418 	rv = AcpiInstallAddressSpaceHandler(hdl,
    419 	    ACPI_ADR_SPACE_GSBUS, acpi_i2c_gsb_handler, acpi_i2c_gsb_init,
    420 	    context);
    421 	if (ACPI_FAILURE(rv)) {
    422 		aprint_error_dev(dev,
    423 		    "couldn't install address space handler: %s",
    424 		    AcpiFormatException(rv));
    425 	}
    426 #endif
    427 }
    428