* [PATCH v2 0/2] eeprom: eeprom_93xx46: Add support for microchip 93LC46B eeprom
@ 2021-01-05 10:58 Aswath Govindraju
2021-01-05 10:58 ` [PATCH v2 1/2] Documentation: devicetree: Add new compatible string for eeprom microchip 93LC46B Aswath Govindraju
2021-01-05 10:58 ` [PATCH v2 2/2] misc: eeprom_93xx46: Add quirk to support Microchip 93LC46B eeprom Aswath Govindraju
0 siblings, 2 replies; 4+ messages in thread
From: Aswath Govindraju @ 2021-01-05 10:58 UTC (permalink / raw)
Cc: Vignesh Raghavendra, Sekhar Nori, Kishon Vijay Abraham I,
Pratyush Yadav, Aswath Govindraju, Rob Herring, Arnd Bergmann,
Greg Kroah-Hartman, Vadym Kochan, devicetree, linux-kernel
This series of patches adds support for microchip 93LC46B eeprom by
- Adding a new compatible string
- Adding a quirk to send extra bit after the address to ignore the
zero bit sent before data, during a read transfer.
changes since v1:
- changed the compatible string to lower case.
- changed the variable for private data to lower case.
Aswath Govindraju (2):
Documentation: devicetree: Add new compatible string for eeprom
microchip 93LC46B
misc: eeprom_93xx46: Add quirk to support Microchip 93LC46B eeprom
.../devicetree/bindings/misc/eeprom-93xx46.txt | 1 +
drivers/misc/eeprom/eeprom_93xx46.c | 15 +++++++++++++++
include/linux/eeprom_93xx46.h | 2 ++
3 files changed, 18 insertions(+)
--
2.17.1
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH v2 1/2] Documentation: devicetree: Add new compatible string for eeprom microchip 93LC46B
2021-01-05 10:58 [PATCH v2 0/2] eeprom: eeprom_93xx46: Add support for microchip 93LC46B eeprom Aswath Govindraju
@ 2021-01-05 10:58 ` Aswath Govindraju
2021-01-11 23:32 ` Rob Herring
2021-01-05 10:58 ` [PATCH v2 2/2] misc: eeprom_93xx46: Add quirk to support Microchip 93LC46B eeprom Aswath Govindraju
1 sibling, 1 reply; 4+ messages in thread
From: Aswath Govindraju @ 2021-01-05 10:58 UTC (permalink / raw)
Cc: Vignesh Raghavendra, Sekhar Nori, Kishon Vijay Abraham I,
Pratyush Yadav, Aswath Govindraju, Rob Herring, Arnd Bergmann,
Greg Kroah-Hartman, Vadym Kochan, devicetree, linux-kernel
Add a new compatible string for eeprom microchip 93LC46B in eeprom-93xx46
dt-binding file as it belongs to the 93xx46 family of devices.
Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
---
Documentation/devicetree/bindings/misc/eeprom-93xx46.txt | 1 +
1 file changed, 1 insertion(+)
diff --git a/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt b/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt
index a8ebb4621f79..7b636b7a8311 100644
--- a/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt
+++ b/Documentation/devicetree/bindings/misc/eeprom-93xx46.txt
@@ -4,6 +4,7 @@ Required properties:
- compatible : shall be one of:
"atmel,at93c46d"
"eeprom-93xx46"
+ "microchip,93lc46b"
- data-size : number of data bits per word (either 8 or 16)
Optional properties:
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH v2 2/2] misc: eeprom_93xx46: Add quirk to support Microchip 93LC46B eeprom
2021-01-05 10:58 [PATCH v2 0/2] eeprom: eeprom_93xx46: Add support for microchip 93LC46B eeprom Aswath Govindraju
2021-01-05 10:58 ` [PATCH v2 1/2] Documentation: devicetree: Add new compatible string for eeprom microchip 93LC46B Aswath Govindraju
@ 2021-01-05 10:58 ` Aswath Govindraju
1 sibling, 0 replies; 4+ messages in thread
From: Aswath Govindraju @ 2021-01-05 10:58 UTC (permalink / raw)
Cc: Vignesh Raghavendra, Sekhar Nori, Kishon Vijay Abraham I,
Pratyush Yadav, Aswath Govindraju, Rob Herring, Arnd Bergmann,
Greg Kroah-Hartman, Vadym Kochan, devicetree, linux-kernel
A dummy zero bit is sent preceding the data during a read transfer by the
Microchip 93LC46B eeprom (section 2.7 of[1]). This results in right shift
of data during a read. In order to ignore this bit a quirk can be added to
send an extra zero bit after the read address.
Add a quirk to ignore the zero bit sent before data by adding a zero bit
after the read address.
[1] - https://www.mouser.com/datasheet/2/268/20001749K-277859.pdf
Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
---
drivers/misc/eeprom/eeprom_93xx46.c | 15 +++++++++++++++
include/linux/eeprom_93xx46.h | 2 ++
2 files changed, 17 insertions(+)
diff --git a/drivers/misc/eeprom/eeprom_93xx46.c b/drivers/misc/eeprom/eeprom_93xx46.c
index 7c45f82b4302..a18247696ce7 100644
--- a/drivers/misc/eeprom/eeprom_93xx46.c
+++ b/drivers/misc/eeprom/eeprom_93xx46.c
@@ -35,6 +35,10 @@ static const struct eeprom_93xx46_devtype_data atmel_at93c46d_data = {
EEPROM_93XX46_QUIRK_INSTRUCTION_LENGTH,
};
+static const struct eeprom_93xx46_devtype_data microchip_93lc46b_data = {
+ .quirks = EEPROM_93XX46_QUIRK_EXTRA_READ_CYCLE,
+};
+
struct eeprom_93xx46_dev {
struct spi_device *spi;
struct eeprom_93xx46_platform_data *pdata;
@@ -55,6 +59,11 @@ static inline bool has_quirk_instruction_length(struct eeprom_93xx46_dev *edev)
return edev->pdata->quirks & EEPROM_93XX46_QUIRK_INSTRUCTION_LENGTH;
}
+static inline bool has_quirk_extra_read_cycle(struct eeprom_93xx46_dev *edev)
+{
+ return edev->pdata->quirks & EEPROM_93XX46_QUIRK_EXTRA_READ_CYCLE;
+}
+
static int eeprom_93xx46_read(void *priv, unsigned int off,
void *val, size_t count)
{
@@ -96,6 +105,11 @@ static int eeprom_93xx46_read(void *priv, unsigned int off,
dev_dbg(&edev->spi->dev, "read cmd 0x%x, %d Hz\n",
cmd_addr, edev->spi->max_speed_hz);
+ if (has_quirk_extra_read_cycle(edev)) {
+ cmd_addr <<= 1;
+ bits += 1;
+ }
+
spi_message_init(&m);
t[0].tx_buf = (char *)&cmd_addr;
@@ -363,6 +377,7 @@ static void select_deassert(void *context)
static const struct of_device_id eeprom_93xx46_of_table[] = {
{ .compatible = "eeprom-93xx46", },
{ .compatible = "atmel,at93c46d", .data = &atmel_at93c46d_data, },
+ { .compatible = "microchip,93lc46b", .data = µchip_93lc46b_data, },
{}
};
MODULE_DEVICE_TABLE(of, eeprom_93xx46_of_table);
diff --git a/include/linux/eeprom_93xx46.h b/include/linux/eeprom_93xx46.h
index eec7928ff8fe..99580c22f91a 100644
--- a/include/linux/eeprom_93xx46.h
+++ b/include/linux/eeprom_93xx46.h
@@ -16,6 +16,8 @@ struct eeprom_93xx46_platform_data {
#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)
+/* Add extra cycle after address during a read */
+#define EEPROM_93XX46_QUIRK_EXTRA_READ_CYCLE BIT(2)
/*
* optional hooks to control additional logic
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2 1/2] Documentation: devicetree: Add new compatible string for eeprom microchip 93LC46B
2021-01-05 10:58 ` [PATCH v2 1/2] Documentation: devicetree: Add new compatible string for eeprom microchip 93LC46B Aswath Govindraju
@ 2021-01-11 23:32 ` Rob Herring
0 siblings, 0 replies; 4+ messages in thread
From: Rob Herring @ 2021-01-11 23:32 UTC (permalink / raw)
To: Aswath Govindraju
Cc: Pratyush Yadav, devicetree, Greg Kroah-Hartman,
Kishon Vijay Abraham I, Arnd Bergmann, Vadym Kochan,
Vignesh Raghavendra, Rob Herring, Sekhar Nori, linux-kernel
On Tue, 05 Jan 2021 16:28:11 +0530, Aswath Govindraju wrote:
> Add a new compatible string for eeprom microchip 93LC46B in eeprom-93xx46
> dt-binding file as it belongs to the 93xx46 family of devices.
>
> Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
> ---
> Documentation/devicetree/bindings/misc/eeprom-93xx46.txt | 1 +
> 1 file changed, 1 insertion(+)
>
Reviewed-by: Rob Herring <robh@kernel.org>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2021-01-05 10:58 [PATCH v2 0/2] eeprom: eeprom_93xx46: Add support for microchip 93LC46B eeprom Aswath Govindraju
2021-01-05 10:58 ` [PATCH v2 1/2] Documentation: devicetree: Add new compatible string for eeprom microchip 93LC46B Aswath Govindraju
2021-01-11 23:32 ` Rob Herring
2021-01-05 10:58 ` [PATCH v2 2/2] misc: eeprom_93xx46: Add quirk to support Microchip 93LC46B eeprom Aswath Govindraju
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