diff options
| -rw-r--r-- | drivers/platform/chrome/cros_ec_lpc.c | 121 |
1 files changed, 100 insertions, 21 deletions
diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c index ba3f6c730c6f..ee9e3c8685cf 100644 --- a/drivers/platform/chrome/cros_ec_lpc.c +++ b/drivers/platform/chrome/cros_ec_lpc.c @@ -70,6 +70,8 @@ struct lpc_driver_data { /** * struct cros_ec_lpc - LPC device-specific data * @mmio_memory_base: The first I/O port addressing EC mapped memory. + * @base: For EC supporting memory mapping, base address of the mapped region. + * @mem32: Information about the memory mapped register region, if present. * @read: Copy length bytes from EC address offset into buffer dest. * Returns a negative error code on error, or the 8-bit checksum * of all bytes read. @@ -79,6 +81,8 @@ struct lpc_driver_data { */ struct cros_ec_lpc { u16 mmio_memory_base; + void __iomem *base; + struct acpi_resource_fixed_memory32 mem32; int (*read)(struct cros_ec_lpc *ec_lpc, unsigned int offset, unsigned int length, u8 *dest); int (*write)(struct cros_ec_lpc *ec_lpc, unsigned int offset, @@ -160,6 +164,45 @@ static int cros_ec_lpc_mec_write_bytes(struct cros_ec_lpc *ec_lpc, unsigned int length, (u8 *)msg) : cros_ec_lpc_write_bytes(ec_lpc, offset, length, msg); } + +static int cros_ec_lpc_direct_read(struct cros_ec_lpc *ec_lpc, unsigned int offset, + unsigned int length, u8 *dest) +{ + int sum = 0; + int i; + + if (offset < EC_HOST_CMD_REGION0 || offset > EC_LPC_ADDR_MEMMAP + + EC_MEMMAP_SIZE) { + return cros_ec_lpc_read_bytes(ec_lpc, offset, length, dest); + } + + for (i = 0; i < length; ++i) { + dest[i] = readb(ec_lpc->base + offset - EC_HOST_CMD_REGION0 + i); + sum += dest[i]; + } + + /* Return checksum of all bytes read */ + return sum; +} + +static int cros_ec_lpc_direct_write(struct cros_ec_lpc *ec_lpc, unsigned int offset, + unsigned int length, const u8 *msg) +{ + int sum = 0; + int i; + + if (offset < EC_HOST_CMD_REGION0 || offset > EC_LPC_ADDR_MEMMAP + + EC_MEMMAP_SIZE) { + return cros_ec_lpc_write_bytes(ec_lpc, offset, length, msg); + } + + for (i = 0; i < length; ++i) { + writeb(msg[i], ec_lpc->base + offset - EC_HOST_CMD_REGION0 + i); + sum += msg[i]; + } + + /* Return checksum of all bytes written */ + return sum; } static int ec_response_timed_out(struct cros_ec_lpc *ec_lpc) @@ -450,6 +493,20 @@ static struct acpi_device *cros_ec_lpc_get_device(const char *id) return adev; } +static acpi_status cros_ec_lpc_resources(struct acpi_resource *res, void *data) +{ + struct cros_ec_lpc *ec_lpc = data; + + switch (res->type) { + case ACPI_RESOURCE_TYPE_FIXED_MEMORY32: + ec_lpc->mem32 = res->data.fixed_memory32; + break; + default: + break; + } + return AE_OK; +} + static int cros_ec_lpc_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -498,29 +555,52 @@ static int cros_ec_lpc_probe(struct platform_device *pdev) dev_info(dev, "got AML mutex '%s'", name); } } - - /* - * The Framework Laptop (and possibly other non-ChromeOS devices) - * only exposes the eight I/O ports that are required for the Microchip EC. - * Requesting a larger reservation will fail. - */ - if (!devm_request_region(dev, EC_HOST_CMD_REGION0, - EC_HOST_CMD_MEC_REGION_SIZE, dev_name(dev))) { - dev_err(dev, "couldn't reserve MEC region\n"); - return -EBUSY; + adev = ACPI_COMPANION(dev); + if (adev) { + /* + * Retrieve the resource information in the CRS register, if available. + */ + status = acpi_walk_resources(adev->handle, METHOD_NAME__CRS, + cros_ec_lpc_resources, ec_lpc); + if (ACPI_FAILURE(status)) { + dev_err(dev, "failed to get resources\n"); + return -ENODEV; + } + if (ec_lpc->mem32.address_length) { + ec_lpc->base = devm_ioremap(dev, + ec_lpc->mem32.address, + ec_lpc->mem32.address_length); + if (!ec_lpc->base) + return -EINVAL; + + ec_lpc->read = cros_ec_lpc_direct_read; + ec_lpc->write = cros_ec_lpc_direct_write; + } } + if (!ec_lpc->read) { + /* + * The Framework Laptop (and possibly other non-ChromeOS devices) + * only exposes the eight I/O ports that are required for the Microchip EC. + * Requesting a larger reservation will fail. + */ + if (!devm_request_region(dev, EC_HOST_CMD_REGION0, + EC_HOST_CMD_MEC_REGION_SIZE, dev_name(dev))) { + dev_err(dev, "couldn't reserve MEC region\n"); + return -EBUSY; + } - cros_ec_lpc_mec_init(EC_HOST_CMD_REGION0, - EC_LPC_ADDR_MEMMAP + EC_MEMMAP_SIZE); + cros_ec_lpc_mec_init(EC_HOST_CMD_REGION0, + EC_LPC_ADDR_MEMMAP + EC_MEMMAP_SIZE); - /* - * Read the mapped ID twice, the first one is assuming the - * EC is a Microchip Embedded Controller (MEC) variant, if the - * protocol fails, fallback to the non MEC variant and try to - * read again the ID. - */ - ec_lpc->read = cros_ec_lpc_mec_read_bytes; - ec_lpc->write = cros_ec_lpc_mec_write_bytes; + /* + * Read the mapped ID twice, the first one is assuming the + * EC is a Microchip Embedded Controller (MEC) variant, if the + * protocol fails, fallback to the non MEC variant and try to + * read again the ID. + */ + ec_lpc->read = cros_ec_lpc_mec_read_bytes; + ec_lpc->write = cros_ec_lpc_mec_write_bytes; + } ret = ec_lpc->read(ec_lpc, EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID, 2, buf); if (ret < 0) return ret; @@ -594,7 +674,6 @@ static int cros_ec_lpc_probe(struct platform_device *pdev) * Connect a notify handler to process MKBP messages if we have a * companion ACPI device. */ - adev = ACPI_COMPANION(dev); if (adev) { status = acpi_install_notify_handler(adev->handle, ACPI_ALL_NOTIFY, |