From 000bee0ed70af79e610444096fb453430220960f Mon Sep 17 00:00:00 2001
From: Stefan Binding <sbinding@opensource.cirrus.com>
Date: Fri, 21 Jan 2022 17:24:24 +0000
Subject: [PATCH] spi: Create helper API to lookup ACPI info for spi device
Git-commit: 000bee0ed70af79e610444096fb453430220960f
Patch-mainline: v5.18-rc1
References: bsc#1203699
This can then be used to find a spi resource inside an
ACPI node, and allocate a spi device.
Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220121172431.6876-3-sbinding@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/spi/spi.c | 46 ++++++++++++++++++++++++++++++++++++----------
include/linux/spi/spi.h | 6 ++++++
2 files changed, 42 insertions(+), 10 deletions(-)
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -2335,8 +2335,18 @@ static int acpi_spi_add_resource(struct
return 1;
}
-static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
- struct acpi_device *adev)
+/**
+ * acpi_spi_device_alloc - Allocate a spi device, and fill it in with ACPI information
+ * @ctlr: controller to which the spi device belongs
+ * @adev: ACPI Device for the spi device
+ *
+ * This should be used to allocate a new spi device from and ACPI Node.
+ * The caller is responsible for calling spi_add_device to register the spi device.
+ *
+ * Return: a pointer to the new device, or ERR_PTR on error.
+ */
+struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr,
+ struct acpi_device *adev)
{
acpi_handle parent_handle = NULL;
struct list_head resource_list;
@@ -2344,10 +2354,6 @@ static acpi_status acpi_register_spi_dev
struct spi_device *spi;
int ret;
- if (acpi_bus_get_status(adev) || !adev->status.present ||
- acpi_device_enumerated(adev))
- return AE_OK;
-
lookup.ctlr = ctlr;
lookup.irq = -1;
@@ -2358,7 +2364,7 @@ static acpi_status acpi_register_spi_dev
if (ret < 0)
/* found SPI in _CRS but it points to another controller */
- return AE_OK;
+ return ERR_PTR(-ENODEV);
if (!lookup.max_speed_hz &&
ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) &&
@@ -2368,16 +2374,15 @@ static acpi_status acpi_register_spi_dev
}
if (!lookup.max_speed_hz)
- return AE_OK;
+ return ERR_PTR(-ENODEV);
spi = spi_alloc_device(ctlr);
if (!spi) {
dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",
dev_name(&adev->dev));
- return AE_NO_MEMORY;
+ return ERR_PTR(-ENOMEM);
}
-
ACPI_COMPANION_SET(&spi->dev, adev);
spi->max_speed_hz = lookup.max_speed_hz;
spi->mode |= lookup.mode;
@@ -2385,6 +2390,27 @@ static acpi_status acpi_register_spi_dev
spi->bits_per_word = lookup.bits_per_word;
spi->chip_select = lookup.chip_select;
+ return spi;
+}
+EXPORT_SYMBOL_GPL(acpi_spi_device_alloc);
+
+static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
+ struct acpi_device *adev)
+{
+ struct spi_device *spi;
+
+ if (acpi_bus_get_status(adev) || !adev->status.present ||
+ acpi_device_enumerated(adev))
+ return AE_OK;
+
+ spi = acpi_spi_device_alloc(ctlr, adev);
+ if (IS_ERR(spi)) {
+ if (PTR_ERR(spi) == -ENOMEM)
+ return AE_NO_MEMORY;
+ else
+ return AE_OK;
+ }
+
acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
sizeof(spi->modalias));
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -17,6 +17,7 @@
#include <linux/ptp_clock_kernel.h>
#include <uapi/linux/spi/spi.h>
+#include <linux/acpi.h>
struct dma_chan;
struct software_node;
@@ -768,6 +769,11 @@ extern void spi_unregister_controller(st
extern struct spi_controller *spi_busnum_to_master(u16 busnum);
+#if IS_ENABLED(CONFIG_ACPI)
+extern struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr,
+ struct acpi_device *adev);
+#endif
+
/*
* SPI resource management while processing a SPI message
*/