* [PATCH 1/7] misc: eeprom: 93xx46: Fix 16-bit read and write accesses.
2015-11-17 4:16 [PATCH 0/7] Devicetree support for misc/eeprom/eeprom_93xx46 Cory Tusar
@ 2015-11-17 4:16 ` Cory Tusar
2015-11-17 4:16 ` [PATCH 2/7] misc: eeprom: 93xx46: Add DT bindings to eeprom_93xx46 driver Cory Tusar
` (5 subsequent siblings)
6 siblings, 0 replies; 14+ messages in thread
From: Cory Tusar @ 2015-11-17 4:16 UTC (permalink / raw)
To: robh+dt, pawel.moll, mark.rutland, ijc+devicetree, galak, agust,
gregkh
Cc: jic23, vz, broonie, afd, andrew, Chris.Healy, Keith.Vennel,
devicetree, linux-kernel, Cory Tusar
Compatible at93xx46 devices from both Microchip and Atmel expect a
word-based address, regardless of whether the device is strapped for 8-
or 16-bit operation. However, the offset parameter passed in when
reading or writing at a specific location is always specified in terms
of bytes.
This commit fixes 16-bit read and write accesses by shifting the offset
parameter to account for this difference between a byte offset and a
word-based address.
Signed-off-by: Cory Tusar <cory.tusar@pid1solutions.com>
---
drivers/misc/eeprom/eeprom_93xx46.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/misc/eeprom/eeprom_93xx46.c b/drivers/misc/eeprom/eeprom_93xx46.c
index ff63f05..e1bf0a5 100644
--- a/drivers/misc/eeprom/eeprom_93xx46.c
+++ b/drivers/misc/eeprom/eeprom_93xx46.c
@@ -54,7 +54,7 @@ eeprom_93xx46_bin_read(struct file *filp, struct kobject *kobj,
cmd_addr |= off & 0x7f;
bits = 10;
} else {
- cmd_addr |= off & 0x3f;
+ cmd_addr |= (off >> 1) & 0x3f;
bits = 9;
}
@@ -155,7 +155,7 @@ eeprom_93xx46_write_word(struct eeprom_93xx46_dev *edev,
bits = 10;
data_len = 1;
} else {
- cmd_addr |= off & 0x3f;
+ cmd_addr |= (off >> 1) & 0x3f;
bits = 9;
data_len = 2;
}
--
2.4.10
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH 2/7] misc: eeprom: 93xx46: Add DT bindings to eeprom_93xx46 driver.
2015-11-17 4:16 [PATCH 0/7] Devicetree support for misc/eeprom/eeprom_93xx46 Cory Tusar
2015-11-17 4:16 ` [PATCH 1/7] misc: eeprom: 93xx46: Fix 16-bit read and write accesses Cory Tusar
@ 2015-11-17 4:16 ` Cory Tusar
[not found] ` <1447733796-15546-3-git-send-email-cory.tusar-J6Z/VSE8EyIAspv4Qr0y0gC/G2K4zDHf@public.gmane.org>
[not found] ` <1447733796-15546-1-git-send-email-cory.tusar-J6Z/VSE8EyIAspv4Qr0y0gC/G2K4zDHf@public.gmane.org>
` (4 subsequent siblings)
6 siblings, 1 reply; 14+ messages in thread
From: Cory Tusar @ 2015-11-17 4:16 UTC (permalink / raw)
To: robh+dt, pawel.moll, mark.rutland, ijc+devicetree, galak, agust,
gregkh
Cc: jic23, vz, broonie, afd, andrew, Chris.Healy, Keith.Vennel,
devicetree, linux-kernel, Cory Tusar
This commit documents bindings to be added to the eeprom_93xx46 driver
which allow device word size and read-only attributes to be specified
via devicetree.
Currently the only supported device is a generic "eeprom-93xx46", which
mirrors the configuration options previously available as a platform
device.
Signed-off-by: Cory Tusar <cory.tusar@pid1solutions.com>
---
.../devicetree/bindings/misc/eeprom-93xx46.txt | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt b/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt
new file mode 100644
index 0000000..ba493a8
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt
@@ -0,0 +1,20 @@
+EEPROMs (SPI) compatible with Microchip Technology 93xx46 family.
+
+Required properties:
+- compatible : "eeprom-93xx46"
+- data-size : number of data bits per word (either 8 or 16)
+
+Optional properties:
+- read-only : parameter-less property which disables writes to the EEPROM
+
+Property rules described in Documentation/devicetree/bindings/spi/spi-bus.txt
+apply. In particular, "reg" and "spi-max-frequency" properties must be given.
+
+Example:
+ 93c46c@0 {
+ compatible = "eeprom-93xx46";
+ reg = <0>;
+ spi-max-frequency = <1000000>;
+ spi-cs-high;
+ data-size = <8>;
+ };
--
2.4.10
^ permalink raw reply related [flat|nested] 14+ messages in thread[parent not found: <1447733796-15546-1-git-send-email-cory.tusar-J6Z/VSE8EyIAspv4Qr0y0gC/G2K4zDHf@public.gmane.org>]
* [PATCH 3/7] misc: eeprom: 93xx46: Implement eeprom_93xx46 DT bindings.
[not found] ` <1447733796-15546-1-git-send-email-cory.tusar-J6Z/VSE8EyIAspv4Qr0y0gC/G2K4zDHf@public.gmane.org>
@ 2015-11-17 4:16 ` Cory Tusar
0 siblings, 0 replies; 14+ messages in thread
From: Cory Tusar @ 2015-11-17 4:16 UTC (permalink / raw)
To: robh+dt-DgEjT+Ai2ygdnm+yROfE0A, pawel.moll-5wv7dgnIgG8,
mark.rutland-5wv7dgnIgG8, ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg,
galak-sgV2jX0FEOL9JmXXK+q4OQ, agust-ynQEQJNshbs,
gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r
Cc: jic23-DgEjT+Ai2ygdnm+yROfE0A, vz-ChpfBGZJDbMAvxtiuMwx3w,
broonie-DgEjT+Ai2ygdnm+yROfE0A, afd-l0cyMroinI0,
andrew-g2DYL2Zd6BY, Chris.Healy-c8ZVq/bFV1I,
Keith.Vennel-c8ZVq/bFV1I, devicetree-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA, Cory Tusar
This commit implements bindings in the eeprom_93xx46 driver allowing
device word size and read-only attributes to be specified via
devicetree.
Signed-off-by: Cory Tusar <cory.tusar-J6Z/VSE8EyIAspv4Qr0y0gC/G2K4zDHf@public.gmane.org>
---
drivers/misc/eeprom/eeprom_93xx46.c | 62 +++++++++++++++++++++++++++++++++++++
1 file changed, 62 insertions(+)
diff --git a/drivers/misc/eeprom/eeprom_93xx46.c b/drivers/misc/eeprom/eeprom_93xx46.c
index e1bf0a5..1f29d9a 100644
--- a/drivers/misc/eeprom/eeprom_93xx46.c
+++ b/drivers/misc/eeprom/eeprom_93xx46.c
@@ -13,6 +13,8 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/sysfs.h>
@@ -294,12 +296,71 @@ static ssize_t eeprom_93xx46_store_erase(struct device *dev,
}
static DEVICE_ATTR(erase, S_IWUSR, NULL, eeprom_93xx46_store_erase);
+#ifdef CONFIG_OF
+static const struct of_device_id eeprom_93xx46_of_table[] = {
+ { .compatible = "eeprom-93xx46", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, eeprom_93xx46_of_table);
+
+static int eeprom_93xx46_probe_dt(struct spi_device *spi)
+{
+ struct device_node *np = spi->dev.of_node;
+ struct eeprom_93xx46_platform_data *pd;
+ u32 tmp;
+ int ret;
+
+ if (!of_match_device(eeprom_93xx46_of_table, &spi->dev))
+ return 0;
+
+ pd = devm_kzalloc(&spi->dev, sizeof(*pd), GFP_KERNEL);
+ if (!pd)
+ return -ENOMEM;
+
+ ret = of_property_read_u32(np, "data-size", &tmp);
+ if (ret < 0) {
+ dev_err(&spi->dev, "data-size property not found\n");
+ goto error_free;
+ }
+
+ if (tmp == 8) {
+ pd->flags |= EE_ADDR8;
+ } else if (tmp == 16) {
+ pd->flags |= EE_ADDR16;
+ } else {
+ dev_err(&spi->dev, "invalid data-size (%d)\n", tmp);
+ goto error_free;
+ }
+
+ if (of_property_read_bool(np, "read-only"))
+ pd->flags |= EE_READONLY;
+
+ spi->dev.platform_data = pd;
+
+ return 1;
+
+error_free:
+ devm_kfree(&spi->dev, pd);
+ return ret;
+}
+
+#else
+static inline int eeprom_93xx46_probe_dt(struct spi_device *spi)
+{
+ return 0;
+}
+#endif
+
static int eeprom_93xx46_probe(struct spi_device *spi)
{
struct eeprom_93xx46_platform_data *pd;
struct eeprom_93xx46_dev *edev;
int err;
+ err = eeprom_93xx46_probe_dt(spi);
+ if (err < 0)
+ return err;
+
pd = spi->dev.platform_data;
if (!pd) {
dev_err(&spi->dev, "missing platform data\n");
@@ -370,6 +431,7 @@ static int eeprom_93xx46_remove(struct spi_device *spi)
static struct spi_driver eeprom_93xx46_driver = {
.driver = {
.name = "93xx46",
+ .of_match_table = eeprom_93xx46_of_table,
},
.probe = eeprom_93xx46_probe,
.remove = eeprom_93xx46_remove,
--
2.4.10
--
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More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply related [flat|nested] 14+ messages in thread
* [PATCH 4/7] misc: eeprom: 93xx46: Add DT binding for Atmel AT93C46D devices.
2015-11-17 4:16 [PATCH 0/7] Devicetree support for misc/eeprom/eeprom_93xx46 Cory Tusar
` (2 preceding siblings ...)
[not found] ` <1447733796-15546-1-git-send-email-cory.tusar-J6Z/VSE8EyIAspv4Qr0y0gC/G2K4zDHf@public.gmane.org>
@ 2015-11-17 4:16 ` Cory Tusar
[not found] ` <1447733796-15546-5-git-send-email-cory.tusar-J6Z/VSE8EyIAspv4Qr0y0gC/G2K4zDHf@public.gmane.org>
2015-11-17 4:16 ` [PATCH 5/7] misc: eeprom: 93xx46: Add quirks to support Atmel AT93C46D device Cory Tusar
` (2 subsequent siblings)
6 siblings, 1 reply; 14+ messages in thread
From: Cory Tusar @ 2015-11-17 4:16 UTC (permalink / raw)
To: robh+dt, pawel.moll, mark.rutland, ijc+devicetree, galak, agust,
gregkh
Cc: jic23, vz, broonie, afd, andrew, Chris.Healy, Keith.Vennel,
devicetree, linux-kernel, Cory Tusar
This commit adds a compatible string to the eeprom_93xx46 devicetree
bindings in support of Atmel AT93C46D devices.
Signed-off-by: Cory Tusar <cory.tusar@pid1solutions.com>
---
Documentation/devicetree/bindings/misc/eeprom-93xx46.txt | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt b/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt
index ba493a8..34a0cc2 100644
--- a/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt
+++ b/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt
@@ -1,7 +1,7 @@
EEPROMs (SPI) compatible with Microchip Technology 93xx46 family.
Required properties:
-- compatible : "eeprom-93xx46"
+- compatible : "eeprom-93xx46", "atmel,at93c46d"
- data-size : number of data bits per word (either 8 or 16)
Optional properties:
--
2.4.10
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH 5/7] misc: eeprom: 93xx46: Add quirks to support Atmel AT93C46D device.
2015-11-17 4:16 [PATCH 0/7] Devicetree support for misc/eeprom/eeprom_93xx46 Cory Tusar
` (3 preceding siblings ...)
2015-11-17 4:16 ` [PATCH 4/7] misc: eeprom: 93xx46: Add DT binding for Atmel AT93C46D devices Cory Tusar
@ 2015-11-17 4:16 ` Cory Tusar
2015-11-17 4:16 ` [PATCH 6/7] misc: eeprom: 93xx46: Add DT binding for a GPIO 'select' line Cory Tusar
2015-11-17 4:16 ` [PATCH 7/7] misc: eeprom: 93xx46: Add support " Cory Tusar
6 siblings, 0 replies; 14+ messages in thread
From: Cory Tusar @ 2015-11-17 4:16 UTC (permalink / raw)
To: robh+dt, pawel.moll, mark.rutland, ijc+devicetree, galak, agust,
gregkh
Cc: jic23, vz, broonie, afd, andrew, Chris.Healy, Keith.Vennel,
devicetree, linux-kernel, Cory Tusar
Atmel devices in this family have some quirks not found in other similar
chips - they do not support a sequential read of the entire EEPROM
contents, and the control word sent at the start of each operation
varies in bit length.
This commit adds quirk support to the driver and modifies the read
implementation to support non-sequential reads for consistency with
other misc/eeprom drivers.
Tested on a custom Freescale VF610-based platform, with an AT93C46D
device attached via dspi2. The spi-gpio driver was used to allow the
necessary non-byte-sized transfers.
Signed-off-by: Cory Tusar <cory.tusar@pid1solutions.com>
---
drivers/misc/eeprom/eeprom_93xx46.c | 128 ++++++++++++++++++++++++++----------
include/linux/eeprom_93xx46.h | 6 ++
2 files changed, 98 insertions(+), 36 deletions(-)
diff --git a/drivers/misc/eeprom/eeprom_93xx46.c b/drivers/misc/eeprom/eeprom_93xx46.c
index 1f29d9a..0386b03 100644
--- a/drivers/misc/eeprom/eeprom_93xx46.c
+++ b/drivers/misc/eeprom/eeprom_93xx46.c
@@ -27,6 +27,15 @@
#define ADDR_ERAL 0x20
#define ADDR_EWEN 0x30
+struct eeprom_93xx46_devtype_data {
+ unsigned int quirks;
+};
+
+static const struct eeprom_93xx46_devtype_data atmel_at93c46d_data = {
+ .quirks = EEPROM_93XX46_QUIRK_SINGLE_WORD_READ |
+ EEPROM_93XX46_QUIRK_INSTRUCTION_LENGTH,
+};
+
struct eeprom_93xx46_dev {
struct spi_device *spi;
struct eeprom_93xx46_platform_data *pdata;
@@ -35,6 +44,16 @@ struct eeprom_93xx46_dev {
int addrlen;
};
+static inline bool has_quirk_single_word_read(struct eeprom_93xx46_dev *edev)
+{
+ return !!(edev->pdata->quirks & EEPROM_93XX46_QUIRK_SINGLE_WORD_READ);
+}
+
+static inline bool has_quirk_instruction_length(struct eeprom_93xx46_dev *edev)
+{
+ return !!(edev->pdata->quirks & EEPROM_93XX46_QUIRK_INSTRUCTION_LENGTH);
+}
+
static ssize_t
eeprom_93xx46_bin_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr,
@@ -42,58 +61,73 @@ eeprom_93xx46_bin_read(struct file *filp, struct kobject *kobj,
{
struct eeprom_93xx46_dev *edev;
struct device *dev;
- struct spi_message m;
- struct spi_transfer t[2];
- int bits, ret;
- u16 cmd_addr;
+ ssize_t ret = 0;
dev = container_of(kobj, struct device, kobj);
edev = dev_get_drvdata(dev);
- cmd_addr = OP_READ << edev->addrlen;
+ mutex_lock(&edev->lock);
- if (edev->addrlen == 7) {
- cmd_addr |= off & 0x7f;
- bits = 10;
- } else {
- cmd_addr |= (off >> 1) & 0x3f;
- bits = 9;
- }
+ if (edev->pdata->prepare)
+ edev->pdata->prepare(edev);
- dev_dbg(&edev->spi->dev, "read cmd 0x%x, %d Hz\n",
- cmd_addr, edev->spi->max_speed_hz);
+ while (count) {
+ struct spi_message m;
+ struct spi_transfer t[2] = { { 0 } };
+ u16 cmd_addr = OP_READ << edev->addrlen;
+ size_t nbytes = count;
+ int bits;
+ int err;
+
+ if (edev->addrlen == 7) {
+ cmd_addr |= off & 0x7f;
+ bits = 10;
+ if (has_quirk_single_word_read(edev))
+ nbytes = 1;
+ } else {
+ cmd_addr |= (off >> 1) & 0x3f;
+ bits = 9;
+ if (has_quirk_single_word_read(edev))
+ nbytes = 2;
+ }
- spi_message_init(&m);
- memset(t, 0, sizeof(t));
+ dev_dbg(&edev->spi->dev, "read cmd 0x%x, %d Hz\n",
+ cmd_addr, edev->spi->max_speed_hz);
- t[0].tx_buf = (char *)&cmd_addr;
- t[0].len = 2;
- t[0].bits_per_word = bits;
- spi_message_add_tail(&t[0], &m);
+ spi_message_init(&m);
- t[1].rx_buf = buf;
- t[1].len = count;
- t[1].bits_per_word = 8;
- spi_message_add_tail(&t[1], &m);
+ t[0].tx_buf = (char *)&cmd_addr;
+ t[0].len = 2;
+ t[0].bits_per_word = bits;
+ spi_message_add_tail(&t[0], &m);
- mutex_lock(&edev->lock);
+ t[1].rx_buf = buf;
+ t[1].len = count;
+ t[1].bits_per_word = 8;
+ spi_message_add_tail(&t[1], &m);
- if (edev->pdata->prepare)
- edev->pdata->prepare(edev);
+ err = spi_sync(edev->spi, &m);
+ /* have to wait at least Tcsl ns */
+ ndelay(250);
- ret = spi_sync(edev->spi, &m);
- /* have to wait at least Tcsl ns */
- ndelay(250);
- if (ret) {
- dev_err(&edev->spi->dev, "read %zu bytes at %d: err. %d\n",
- count, (int)off, ret);
+ if (err) {
+ dev_err(&edev->spi->dev, "read %zu bytes at %d: err. %d\n",
+ nbytes, (int)off, err);
+ ret = err;
+ break;
+ }
+
+ buf += nbytes;
+ off += nbytes;
+ count -= nbytes;
+ ret += nbytes;
}
if (edev->pdata->finish)
edev->pdata->finish(edev);
mutex_unlock(&edev->lock);
- return ret ? : count;
+ return ret;
}
static int eeprom_93xx46_ew(struct eeprom_93xx46_dev *edev, int is_on)
@@ -112,7 +146,13 @@ static int eeprom_93xx46_ew(struct eeprom_93xx46_dev *edev, int is_on)
bits = 9;
}
- dev_dbg(&edev->spi->dev, "ew cmd 0x%04x\n", cmd_addr);
+ if (has_quirk_instruction_length(edev)) {
+ cmd_addr <<= 2;
+ bits += 2;
+ }
+
+ dev_dbg(&edev->spi->dev, "ew%s cmd 0x%04x, %d bits\n",
+ is_on ? "en" : "ds", cmd_addr, bits);
spi_message_init(&m);
memset(&t, 0, sizeof(t));
@@ -247,6 +287,13 @@ static int eeprom_93xx46_eral(struct eeprom_93xx46_dev *edev)
bits = 9;
}
+ if (has_quirk_instruction_length(edev)) {
+ cmd_addr <<= 2;
+ bits += 2;
+ }
+
+ dev_dbg(&edev->spi->dev, "eral cmd 0x%04x, %d bits\n", cmd_addr, bits);
+
spi_message_init(&m);
memset(&t, 0, sizeof(t));
@@ -299,18 +346,21 @@ static DEVICE_ATTR(erase, S_IWUSR, NULL, eeprom_93xx46_store_erase);
#ifdef CONFIG_OF
static const struct of_device_id eeprom_93xx46_of_table[] = {
{ .compatible = "eeprom-93xx46", },
+ { .compatible = "atmel,at93c46d", .data = &atmel_at93c46d_data, },
{}
};
MODULE_DEVICE_TABLE(of, eeprom_93xx46_of_table);
static int eeprom_93xx46_probe_dt(struct spi_device *spi)
{
+ const struct of_device_id *of_id =
+ of_match_device(eeprom_93xx46_of_table, &spi->dev);
struct device_node *np = spi->dev.of_node;
struct eeprom_93xx46_platform_data *pd;
u32 tmp;
int ret;
- if (!of_match_device(eeprom_93xx46_of_table, &spi->dev))
+ if (!of_id)
return 0;
pd = devm_kzalloc(&spi->dev, sizeof(*pd), GFP_KERNEL);
@@ -335,6 +385,12 @@ static int eeprom_93xx46_probe_dt(struct spi_device *spi)
if (of_property_read_bool(np, "read-only"))
pd->flags |= EE_READONLY;
+ if (of_id->data) {
+ const struct eeprom_93xx46_devtype_data *data = of_id->data;
+
+ pd->quirks = data->quirks;
+ }
+
spi->dev.platform_data = pd;
return 1;
diff --git a/include/linux/eeprom_93xx46.h b/include/linux/eeprom_93xx46.h
index 0679181..92fa4c3 100644
--- a/include/linux/eeprom_93xx46.h
+++ b/include/linux/eeprom_93xx46.h
@@ -9,6 +9,12 @@ struct eeprom_93xx46_platform_data {
#define EE_ADDR16 0x02 /* 16 bit addr. cfg */
#define EE_READONLY 0x08 /* forbid writing */
+ unsigned int quirks;
+/* Single word read transfers only; no sequential read. */
+#define EEPROM_93XX46_QUIRK_SINGLE_WORD_READ (1 << 0)
+/* Instructions such as EWEN are (addrlen + 2) in length. */
+#define EEPROM_93XX46_QUIRK_INSTRUCTION_LENGTH (1 << 1)
+
/*
* optional hooks to control additional logic
* before and after spi transfer.
--
2.4.10
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH 6/7] misc: eeprom: 93xx46: Add DT binding for a GPIO 'select' line.
2015-11-17 4:16 [PATCH 0/7] Devicetree support for misc/eeprom/eeprom_93xx46 Cory Tusar
` (4 preceding siblings ...)
2015-11-17 4:16 ` [PATCH 5/7] misc: eeprom: 93xx46: Add quirks to support Atmel AT93C46D device Cory Tusar
@ 2015-11-17 4:16 ` Cory Tusar
[not found] ` <1447733796-15546-7-git-send-email-cory.tusar-J6Z/VSE8EyIAspv4Qr0y0gC/G2K4zDHf@public.gmane.org>
2015-11-17 4:16 ` [PATCH 7/7] misc: eeprom: 93xx46: Add support " Cory Tusar
6 siblings, 1 reply; 14+ messages in thread
From: Cory Tusar @ 2015-11-17 4:16 UTC (permalink / raw)
To: robh+dt, pawel.moll, mark.rutland, ijc+devicetree, galak, agust,
gregkh
Cc: jic23, vz, broonie, afd, andrew, Chris.Healy, Keith.Vennel,
devicetree, linux-kernel, Cory Tusar
This commit documents an additional devicetree binding in the
eeprom_93x46 driver allowing a GPIO line to function as a 'select'
or 'enable' signal prior to accessing the EEPROM.
Signed-off-by: Cory Tusar <cory.tusar@pid1solutions.com>
---
Documentation/devicetree/bindings/misc/eeprom-93xx46.txt | 3 +++
1 file changed, 3 insertions(+)
diff --git a/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt b/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt
index 34a0cc2..75b16f4 100644
--- a/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt
+++ b/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt
@@ -6,6 +6,8 @@ Required properties:
Optional properties:
- read-only : parameter-less property which disables writes to the EEPROM
+- select-gpio : if present, specifies the GPIO that will be asserted prior to
+ each access to the EEPROM (e.g. for SPI bus multiplexing)
Property rules described in Documentation/devicetree/bindings/spi/spi-bus.txt
apply. In particular, "reg" and "spi-max-frequency" properties must be given.
@@ -17,4 +19,5 @@ Example:
spi-max-frequency = <1000000>;
spi-cs-high;
data-size = <8>;
+ select-gpio = <&gpio4 4 GPIO_ACTIVE_HIGH>;
};
--
2.4.10
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH 7/7] misc: eeprom: 93xx46: Add support for a GPIO 'select' line.
2015-11-17 4:16 [PATCH 0/7] Devicetree support for misc/eeprom/eeprom_93xx46 Cory Tusar
` (5 preceding siblings ...)
2015-11-17 4:16 ` [PATCH 6/7] misc: eeprom: 93xx46: Add DT binding for a GPIO 'select' line Cory Tusar
@ 2015-11-17 4:16 ` Cory Tusar
6 siblings, 0 replies; 14+ messages in thread
From: Cory Tusar @ 2015-11-17 4:16 UTC (permalink / raw)
To: robh+dt, pawel.moll, mark.rutland, ijc+devicetree, galak, agust,
gregkh
Cc: jic23, vz, broonie, afd, andrew, Chris.Healy, Keith.Vennel,
devicetree, linux-kernel, Cory Tusar
This commit adds support to the eeprom_93x46 driver allowing a GPIO line
to function as a 'select' or 'enable' signal prior to accessing the
EEPROM.
Signed-off-by: Cory Tusar <cory.tusar@pid1solutions.com>
---
drivers/misc/eeprom/eeprom_93xx46.c | 26 ++++++++++++++++++++++++++
include/linux/eeprom_93xx46.h | 1 +
2 files changed, 27 insertions(+)
diff --git a/drivers/misc/eeprom/eeprom_93xx46.c b/drivers/misc/eeprom/eeprom_93xx46.c
index 0386b03..3f41696 100644
--- a/drivers/misc/eeprom/eeprom_93xx46.c
+++ b/drivers/misc/eeprom/eeprom_93xx46.c
@@ -10,11 +10,14 @@
#include <linux/delay.h>
#include <linux/device.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_device.h>
+#include <linux/of_gpio.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/sysfs.h>
@@ -344,6 +347,20 @@ static ssize_t eeprom_93xx46_store_erase(struct device *dev,
static DEVICE_ATTR(erase, S_IWUSR, NULL, eeprom_93xx46_store_erase);
#ifdef CONFIG_OF
+static void select_assert(void *context)
+{
+ struct eeprom_93xx46_dev *edev = context;
+
+ gpiod_set_value_cansleep(gpio_to_desc(edev->pdata->select_gpio), 1);
+}
+
+static void select_deassert(void *context)
+{
+ struct eeprom_93xx46_dev *edev = context;
+
+ gpiod_set_value_cansleep(gpio_to_desc(edev->pdata->select_gpio), 0);
+}
+
static const struct of_device_id eeprom_93xx46_of_table[] = {
{ .compatible = "eeprom-93xx46", },
{ .compatible = "atmel,at93c46d", .data = &atmel_at93c46d_data, },
@@ -385,6 +402,15 @@ static int eeprom_93xx46_probe_dt(struct spi_device *spi)
if (of_property_read_bool(np, "read-only"))
pd->flags |= EE_READONLY;
+ ret = of_get_named_gpio(np, "select-gpio", 0);
+ if (ret < 0) {
+ pd->select_gpio = -1;
+ } else {
+ pd->select_gpio = ret;
+ pd->prepare = select_assert;
+ pd->finish = select_deassert;
+ }
+
if (of_id->data) {
const struct eeprom_93xx46_devtype_data *data = of_id->data;
diff --git a/include/linux/eeprom_93xx46.h b/include/linux/eeprom_93xx46.h
index 92fa4c3..aa472c7 100644
--- a/include/linux/eeprom_93xx46.h
+++ b/include/linux/eeprom_93xx46.h
@@ -21,4 +21,5 @@ struct eeprom_93xx46_platform_data {
*/
void (*prepare)(void *);
void (*finish)(void *);
+ unsigned int select_gpio;
};
--
2.4.10
^ permalink raw reply related [flat|nested] 14+ messages in thread