2024-02-12 14:08:34

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH v2 00/12] spi: s3c64xx: remove OF alias ID dependency

The driver was wrong as it assumed that the alias values in devicetree
have a particular meaning in identifying instances. This immediately
breaks when there is a dtb file that does not use the same alias values,
e.g. because it only needs some of the SPI ports.

Tested gs101 SPI with spi-loopback-test, all went fine. I updated
exynos850 as it uses the same USI.SPI_VERSION as gs101. Maybe Sam can
test exynos850, if not, we can drop that patch (12/12).

v2:
- update bindings to consider the asymmetric case where the RX FIFO
depth can differ from the TX FIFO depth
- update commit message in patch 11/12 to describe the GS101 change
(I was wrongly mentioning exynos 850).


Tudor Ambarus (12):
spi: dt-bindings: introduce FIFO depth properties
spi: s3c64xx: define a magic value
spi: s3c64xx: allow full FIFO masks
spi: s3c64xx: determine the fifo depth only once
spi: s3c64xx: retrieve the FIFO depth from the device tree
spi: s3c64xx: allow FIFO depth to be determined from the compatible
spi: s3c64xx: let the SPI core determine the bus number
spi: s3c64xx: introduce s3c64xx_spi_set_port_id()
spi: s3c64xx: get rid of the OF alias ID dependency
spi: s3c64xx: deprecate fifo_lvl_mask, rx_lvl_offset and port_id
spi: s3c64xx: switch gs101 to new port config data
spi: s3c64xx: switch exynos850 to new port config data

.../bindings/spi/spi-controller.yaml | 27 ++++
drivers/spi/spi-s3c64xx.c | 142 ++++++++++++++----
2 files changed, 138 insertions(+), 31 deletions(-)

--
2.43.0.687.g38aa6559b0-goog



2024-02-12 14:08:54

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH v2 01/12] spi: dt-bindings: introduce FIFO depth properties

There are SPI IPs that can be configured by the integrator with a
specific FIFO depth depending on the system's capabilities. For example,
the samsung USI SPI IP can be configured by the integrator with a TX/RX
FIFO from 8 byte to 256 bytes.

Introduce the ``fifo-depth`` property for such instances of IPs where the
same FIFO depth is used for both RX and TX. Introduce ``rx-fifo-depth``
and ``tx-fifo-depth`` properties for cases where the RX FIFO depth is
different from the TX FIFO depth.

Make the dedicated RX/TX properties dependent on each other and mutual
exclusive with the other.

Signed-off-by: Tudor Ambarus <[email protected]>
---
.../bindings/spi/spi-controller.yaml | 27 +++++++++++++++++++
1 file changed, 27 insertions(+)

diff --git a/Documentation/devicetree/bindings/spi/spi-controller.yaml b/Documentation/devicetree/bindings/spi/spi-controller.yaml
index 524f6fe8c27b..add39884d226 100644
--- a/Documentation/devicetree/bindings/spi/spi-controller.yaml
+++ b/Documentation/devicetree/bindings/spi/spi-controller.yaml
@@ -69,6 +69,21 @@ properties:
Should be generally avoided and be replaced by
spi-cs-high + ACTIVE_HIGH.

+ fifo-depth:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Size of the RX and TX data FIFOs in bytes.
+
+ rx-fifo-depth:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Size of the RX data FIFO in bytes.
+
+ tx-fifo-depth:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Size of the TX data FIFO in bytes.
+
num-cs:
$ref: /schemas/types.yaml#/definitions/uint32
description:
@@ -116,6 +131,10 @@ patternProperties:
- compatible
- reg

+dependencies:
+ rx-fifo-depth: [ tx-fifo-depth ]
+ tx-fifo-depth: [ rx-fifo-depth ]
+
allOf:
- if:
not:
@@ -129,6 +148,14 @@ allOf:
properties:
"#address-cells":
const: 0
+ - not:
+ required:
+ - fifo-depth
+ - rx-fifo-depth
+ - not:
+ required:
+ - fifo-depth
+ - tx-fifo-depth

additionalProperties: true

--
2.43.0.687.g38aa6559b0-goog


2024-02-12 14:09:13

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH v2 02/12] spi: s3c64xx: define a magic value

Define a magic value, it will be used in the next patch as well.

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/spi/spi-s3c64xx.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 6f29dca68491..6ff3b25b6feb 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -78,6 +78,7 @@
#define S3C64XX_SPI_INT_RX_FIFORDY_EN (1<<1)
#define S3C64XX_SPI_INT_TX_FIFORDY_EN (1<<0)

+#define S3C64XX_SPI_ST_TX_FIFO_LVL_SHIFT 6
#define S3C64XX_SPI_ST_RX_OVERRUN_ERR (1<<5)
#define S3C64XX_SPI_ST_RX_UNDERRUN_ERR (1<<4)
#define S3C64XX_SPI_ST_TX_OVERRUN_ERR (1<<3)
@@ -108,7 +109,8 @@
#define FIFO_LVL_MASK(i) ((i)->port_conf->fifo_lvl_mask[i->port_id])
#define S3C64XX_SPI_ST_TX_DONE(v, i) (((v) & \
(1 << (i)->port_conf->tx_st_done)) ? 1 : 0)
-#define TX_FIFO_LVL(v, i) (((v) >> 6) & FIFO_LVL_MASK(i))
+#define TX_FIFO_LVL(v, i) (((v) >> S3C64XX_SPI_ST_TX_FIFO_LVL_SHIFT) & \
+ FIFO_LVL_MASK(i))
#define RX_FIFO_LVL(v, i) (((v) >> (i)->port_conf->rx_lvl_offset) & \
FIFO_LVL_MASK(i))
#define FIFO_DEPTH(i) ((FIFO_LVL_MASK(i) >> 1) + 1)
--
2.43.0.687.g38aa6559b0-goog


2024-02-12 14:09:33

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH v2 03/12] spi: s3c64xx: allow full FIFO masks

The driver is wrong because is using partial register field masks for the
SPI_STATUS.{RX, TX}_FIFO_LVL register fields.

We see s3c64xx_spi_port_config.fifo_lvl_mask with different values for
different instances of the same IP. Take s5pv210_spi_port_config for
example, it defines:
.fifo_lvl_mask = { 0x1ff, 0x7F },

fifo_lvl_mask is used to determine the FIFO depth of the instance of the
IP. In this case, the integrator uses a 256 bytes FIFO for the first SPI
instance of the IP, and a 64 bytes FIFO for the second instance. While
the first mask reflects the SPI_STATUS.{RX, TX}_FIFO_LVL register
fields, the second one is two bits short. Using partial field masks is
misleading and can hide problems of the driver's logic.

Allow platforms to specify the full FIFO mask, regardless of the FIFO
depth.

Introduce {rx, tx}_fifomask to represent the SPI_STATUS.{RX, TX}_FIFO_LVL
register fields. It's a shifted mask defining the field's length and
position. We'll be able to deprecate the use of @rx_lvl_offset, as the
shift value can be determined from the mask. The existing compatibles
shall start using {rx, tx}_fifomask so that they use the full field mask
and to avoid shifting the mask to position, and then shifting it back to
zero in the {TX, RX}_FIFO_LVL macros.

@rx_lvl_offset will be deprecated in a further patch, after we have the
infrastructure to deprecate @fifo_lvl_mask as well.

No functional change intended.

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/spi/spi-s3c64xx.c | 40 +++++++++++++++++++++++++++++++++++----
1 file changed, 36 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 6ff3b25b6feb..338ca3f03ea5 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -3,6 +3,7 @@
// Copyright (c) 2009 Samsung Electronics Co., Ltd.
// Jaswinder Singh <[email protected]>

+#include <linux/bitops.h>
#include <linux/bits.h>
#include <linux/clk.h>
#include <linux/delay.h>
@@ -109,10 +110,10 @@
#define FIFO_LVL_MASK(i) ((i)->port_conf->fifo_lvl_mask[i->port_id])
#define S3C64XX_SPI_ST_TX_DONE(v, i) (((v) & \
(1 << (i)->port_conf->tx_st_done)) ? 1 : 0)
-#define TX_FIFO_LVL(v, i) (((v) >> S3C64XX_SPI_ST_TX_FIFO_LVL_SHIFT) & \
- FIFO_LVL_MASK(i))
-#define RX_FIFO_LVL(v, i) (((v) >> (i)->port_conf->rx_lvl_offset) & \
- FIFO_LVL_MASK(i))
+#define TX_FIFO_LVL(v, sdd) (((v) & (sdd)->tx_fifomask) >> \
+ __ffs((sdd)->tx_fifomask))
+#define RX_FIFO_LVL(v, sdd) (((v) & (sdd)->rx_fifomask) >> \
+ __ffs((sdd)->rx_fifomask))
#define FIFO_DEPTH(i) ((FIFO_LVL_MASK(i) >> 1) + 1)

#define S3C64XX_SPI_MAX_TRAILCNT 0x3ff
@@ -136,6 +137,10 @@ struct s3c64xx_spi_dma_data {
* struct s3c64xx_spi_port_config - SPI Controller hardware info
* @fifo_lvl_mask: Bit-mask for {TX|RX}_FIFO_LVL bits in SPI_STATUS register.
* @rx_lvl_offset: Bit offset of RX_FIFO_LVL bits in SPI_STATUS regiter.
+ * @rx_fifomask: SPI_STATUS.RX_FIFO_LVL mask. Shifted mask defining the field's
+ * length and position.
+ * @tx_fifomask: SPI_STATUS.TX_FIFO_LVL mask. Shifted mask defining the field's
+ * length and position.
* @tx_st_done: Bit offset of TX_DONE bit in SPI_STATUS regiter.
* @clk_div: Internal clock divider
* @quirks: Bitmask of known quirks
@@ -154,6 +159,8 @@ struct s3c64xx_spi_dma_data {
struct s3c64xx_spi_port_config {
int fifo_lvl_mask[MAX_SPI_PORTS];
int rx_lvl_offset;
+ u32 rx_fifomask;
+ u32 tx_fifomask;
int tx_st_done;
int quirks;
int clk_div;
@@ -184,6 +191,10 @@ struct s3c64xx_spi_port_config {
* @tx_dma: Local transmit DMA data (e.g. chan and direction)
* @port_conf: Local SPI port configuration data
* @port_id: Port identification number
+ * @rx_fifomask: SPI_STATUS.RX_FIFO_LVL mask. Shifted mask defining the field's
+ * length and position.
+ * @tx_fifomask: SPI_STATUS.TX_FIFO_LVL mask. Shifted mask defining the field's
+ * length and position.
*/
struct s3c64xx_spi_driver_data {
void __iomem *regs;
@@ -203,6 +214,8 @@ struct s3c64xx_spi_driver_data {
struct s3c64xx_spi_dma_data tx_dma;
const struct s3c64xx_spi_port_config *port_conf;
unsigned int port_id;
+ u32 rx_fifomask;
+ u32 tx_fifomask;
};

static void s3c64xx_flush_fifo(struct s3c64xx_spi_driver_data *sdd)
@@ -1183,6 +1196,23 @@ static inline const struct s3c64xx_spi_port_config *s3c64xx_spi_get_port_config(
return (const struct s3c64xx_spi_port_config *)platform_get_device_id(pdev)->driver_data;
}

+static void s3c64xx_spi_set_fifomask(struct s3c64xx_spi_driver_data *sdd)
+{
+ const struct s3c64xx_spi_port_config *port_conf = sdd->port_conf;
+
+ if (port_conf->rx_fifomask)
+ sdd->rx_fifomask = port_conf->rx_fifomask;
+ else
+ sdd->rx_fifomask = FIFO_LVL_MASK(sdd) <<
+ port_conf->rx_lvl_offset;
+
+ if (port_conf->tx_fifomask)
+ sdd->tx_fifomask = port_conf->tx_fifomask;
+ else
+ sdd->tx_fifomask = FIFO_LVL_MASK(sdd) <<
+ S3C64XX_SPI_ST_TX_FIFO_LVL_SHIFT;
+}
+
static int s3c64xx_spi_probe(struct platform_device *pdev)
{
struct resource *mem_res;
@@ -1231,6 +1261,8 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
sdd->port_id = pdev->id;
}

+ s3c64xx_spi_set_fifomask(sdd);
+
sdd->cur_bpw = 8;

sdd->tx_dma.direction = DMA_MEM_TO_DEV;
--
2.43.0.687.g38aa6559b0-goog


2024-02-12 14:10:09

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH v2 05/12] spi: s3c64xx: retrieve the FIFO depth from the device tree

There are SoCs that configure different FIFO depths for their instances
of the SPI IP. See the fifo_lvl_mask defined for exynos4_spi_port_config
for example:
.fifo_lvl_mask = { 0x1ff, 0x7F, 0x7F },
The first instance of the IP is configured with 256 bytes FIFOs, whereas
the last two are configured with 64 bytes FIFOs.

Instead of mangling with the .fifo_lvl_mask and its dependency of the DT
alias ID, allow such SoCs to determine the FIFO depth via the
``fifo-depth`` DT property.

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/spi/spi-s3c64xx.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 72572e23cde5..b1c63f75021d 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -1263,7 +1263,9 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
sdd->port_id = pdev->id;
}

- sdd->fifo_depth = FIFO_DEPTH(sdd);
+ if (of_property_read_u32(pdev->dev.of_node, "fifo-depth",
+ &sdd->fifo_depth))
+ sdd->fifo_depth = FIFO_DEPTH(sdd);

s3c64xx_spi_set_fifomask(sdd);

--
2.43.0.687.g38aa6559b0-goog


2024-02-12 14:10:25

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH v2 06/12] spi: s3c64xx: allow FIFO depth to be determined from the compatible

There are SoCs that use the same FIFO depth for all the instances of the
SPI IP. See the fifo_lvl_mask defined for gs101 for example:
.fifo_lvl_mask = { 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f,
0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f},

Instead of specifying the FIFO depth with the same value for all 16
nodes in this case, allow such SoCs to infer the FIFO depth from the
compatible. There are other SoCs than can benefit of this, see:
{gs101, fsd, exynos850, s3c641, s3c2443}_spi_port_config.

The FIFO depth inferred from the compatible has a higher precedence than
the one that might be specified via device tree, the driver shall know
better.

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/spi/spi-s3c64xx.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index b1c63f75021d..68f95c04d092 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -137,6 +137,7 @@ struct s3c64xx_spi_dma_data {
* struct s3c64xx_spi_port_config - SPI Controller hardware info
* @fifo_lvl_mask: Bit-mask for {TX|RX}_FIFO_LVL bits in SPI_STATUS register.
* @rx_lvl_offset: Bit offset of RX_FIFO_LVL bits in SPI_STATUS regiter.
+ * @fifo_depth: depth of the FIFO.
* @rx_fifomask: SPI_STATUS.RX_FIFO_LVL mask. Shifted mask defining the field's
* length and position.
* @tx_fifomask: SPI_STATUS.TX_FIFO_LVL mask. Shifted mask defining the field's
@@ -159,6 +160,7 @@ struct s3c64xx_spi_dma_data {
struct s3c64xx_spi_port_config {
int fifo_lvl_mask[MAX_SPI_PORTS];
int rx_lvl_offset;
+ unsigned int fifo_depth;
u32 rx_fifomask;
u32 tx_fifomask;
int tx_st_done;
@@ -1263,8 +1265,10 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
sdd->port_id = pdev->id;
}

- if (of_property_read_u32(pdev->dev.of_node, "fifo-depth",
- &sdd->fifo_depth))
+ if (sdd->port_conf->fifo_depth)
+ sdd->fifo_depth = sdd->port_conf->fifo_depth;
+ else if (of_property_read_u32(pdev->dev.of_node, "fifo-depth",
+ &sdd->fifo_depth))
sdd->fifo_depth = FIFO_DEPTH(sdd);

s3c64xx_spi_set_fifomask(sdd);
--
2.43.0.687.g38aa6559b0-goog


2024-02-12 14:10:47

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH v2 04/12] spi: s3c64xx: determine the fifo depth only once

Determine the FIFO depth only once, at probe time.
``sdd->fifo_depth`` can be set later on with the FIFO depth
specified in the device tree.

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/spi/spi-s3c64xx.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 338ca3f03ea5..72572e23cde5 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -191,6 +191,7 @@ struct s3c64xx_spi_port_config {
* @tx_dma: Local transmit DMA data (e.g. chan and direction)
* @port_conf: Local SPI port configuration data
* @port_id: Port identification number
+ * @fifo_depth: depth of the FIFO.
* @rx_fifomask: SPI_STATUS.RX_FIFO_LVL mask. Shifted mask defining the field's
* length and position.
* @tx_fifomask: SPI_STATUS.TX_FIFO_LVL mask. Shifted mask defining the field's
@@ -214,6 +215,7 @@ struct s3c64xx_spi_driver_data {
struct s3c64xx_spi_dma_data tx_dma;
const struct s3c64xx_spi_port_config *port_conf;
unsigned int port_id;
+ unsigned int fifo_depth;
u32 rx_fifomask;
u32 tx_fifomask;
};
@@ -424,7 +426,7 @@ static bool s3c64xx_spi_can_dma(struct spi_controller *host,
struct s3c64xx_spi_driver_data *sdd = spi_controller_get_devdata(host);

if (sdd->rx_dma.ch && sdd->tx_dma.ch)
- return xfer->len > FIFO_DEPTH(sdd);
+ return xfer->len > sdd->fifo_depth;

return false;
}
@@ -548,7 +550,7 @@ static u32 s3c64xx_spi_wait_for_timeout(struct s3c64xx_spi_driver_data *sdd,
void __iomem *regs = sdd->regs;
unsigned long val = 1;
u32 status;
- u32 max_fifo = FIFO_DEPTH(sdd);
+ u32 max_fifo = sdd->fifo_depth;

if (timeout_ms)
val = msecs_to_loops(timeout_ms);
@@ -655,7 +657,7 @@ static int s3c64xx_wait_for_pio(struct s3c64xx_spi_driver_data *sdd,
* For any size less than the fifo size the below code is
* executed atleast once.
*/
- loops = xfer->len / FIFO_DEPTH(sdd);
+ loops = xfer->len / sdd->fifo_depth;
buf = xfer->rx_buf;
do {
/* wait for data to be received in the fifo */
@@ -792,7 +794,7 @@ static int s3c64xx_spi_transfer_one(struct spi_controller *host,
struct spi_transfer *xfer)
{
struct s3c64xx_spi_driver_data *sdd = spi_controller_get_devdata(host);
- const unsigned int fifo_len = FIFO_DEPTH(sdd);
+ const unsigned int fifo_len = sdd->fifo_depth;
const void *tx_buf = NULL;
void *rx_buf = NULL;
int target_len = 0, origin_len = 0;
@@ -1261,6 +1263,8 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
sdd->port_id = pdev->id;
}

+ sdd->fifo_depth = FIFO_DEPTH(sdd);
+
s3c64xx_spi_set_fifomask(sdd);

sdd->cur_bpw = 8;
@@ -1352,7 +1356,7 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d with %d Targets attached\n",
sdd->port_id, host->num_chipselect);
dev_dbg(&pdev->dev, "\tIOmem=[%pR]\tFIFO %dbytes\n",
- mem_res, FIFO_DEPTH(sdd));
+ mem_res, sdd->fifo_depth);

pm_runtime_mark_last_busy(&pdev->dev);
pm_runtime_put_autosuspend(&pdev->dev);
--
2.43.0.687.g38aa6559b0-goog


2024-02-12 14:11:33

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH v2 08/12] spi: s3c64xx: introduce s3c64xx_spi_set_port_id()

Prepare driver to get rid of the of alias ID dependency. Split the
port_id logic into a dedicated method.

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/spi/spi-s3c64xx.c | 37 +++++++++++++++++++++++++------------
1 file changed, 25 insertions(+), 12 deletions(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index ac47755beb02..40de325bd094 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -1200,6 +1200,27 @@ static inline const struct s3c64xx_spi_port_config *s3c64xx_spi_get_port_config(
return (const struct s3c64xx_spi_port_config *)platform_get_device_id(pdev)->driver_data;
}

+static int s3c64xx_spi_set_port_id(struct platform_device *pdev,
+ struct s3c64xx_spi_driver_data *sdd)
+{
+ int ret;
+
+ if (pdev->dev.of_node) {
+ ret = of_alias_get_id(pdev->dev.of_node, "spi");
+ if (ret < 0)
+ return dev_err_probe(&pdev->dev, ret,
+ "Failed to get alias id\n");
+ sdd->port_id = ret;
+ } else {
+ if (pdev->id < 0)
+ return dev_err_probe(&pdev->dev, -EINVAL,
+ "Negative platform ID is not allowed\n");
+ sdd->port_id = pdev->id;
+ }
+
+ return 0;
+}
+
static void s3c64xx_spi_set_fifomask(struct s3c64xx_spi_driver_data *sdd)
{
const struct s3c64xx_spi_port_config *port_conf = sdd->port_conf;
@@ -1252,18 +1273,10 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
sdd->host = host;
sdd->cntrlr_info = sci;
sdd->pdev = pdev;
- if (pdev->dev.of_node) {
- ret = of_alias_get_id(pdev->dev.of_node, "spi");
- if (ret < 0)
- return dev_err_probe(&pdev->dev, ret,
- "Failed to get alias id\n");
- sdd->port_id = ret;
- } else {
- if (pdev->id < 0)
- return dev_err_probe(&pdev->dev, -EINVAL,
- "Negative platform ID is not allowed\n");
- sdd->port_id = pdev->id;
- }
+
+ ret = s3c64xx_spi_set_port_id(pdev, sdd);
+ if (ret)
+ return ret;

if (sdd->port_conf->fifo_depth)
sdd->fifo_depth = sdd->port_conf->fifo_depth;
--
2.43.0.687.g38aa6559b0-goog


2024-02-12 14:11:36

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH v2 07/12] spi: s3c64xx: let the SPI core determine the bus number

Let the core determine the bus number, either by getting the alias ID
(as the driver forces now), or by allocating a dynamic bus number when
the alias is absent. Prepare the driver to allow dt aliases to be
absent.

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/spi/spi-s3c64xx.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 68f95c04d092..ac47755beb02 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -1279,7 +1279,7 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
sdd->rx_dma.direction = DMA_DEV_TO_MEM;

host->dev.of_node = pdev->dev.of_node;
- host->bus_num = sdd->port_id;
+ host->bus_num = -1;
host->setup = s3c64xx_spi_setup;
host->cleanup = s3c64xx_spi_cleanup;
host->prepare_transfer_hardware = s3c64xx_spi_prepare_transfer;
@@ -1360,7 +1360,7 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
}

dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d with %d Targets attached\n",
- sdd->port_id, host->num_chipselect);
+ host->bus_num, host->num_chipselect);
dev_dbg(&pdev->dev, "\tIOmem=[%pR]\tFIFO %dbytes\n",
mem_res, sdd->fifo_depth);

--
2.43.0.687.g38aa6559b0-goog


2024-02-12 14:11:45

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH v2 09/12] spi: s3c64xx: get rid of the OF alias ID dependency

Compatibles that set ``port_conf->{rx, tx}_fifomask`` are now safe to
get rid of the OF alias ID dependency. Let the driver probe even without
the alias for these.

With this we also protect the FIFO_LVL_MASK calls from
s3c64xx_spi_set_fifomask().

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/spi/spi-s3c64xx.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 40de325bd094..d2d1c9767145 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -1203,8 +1203,12 @@ static inline const struct s3c64xx_spi_port_config *s3c64xx_spi_get_port_config(
static int s3c64xx_spi_set_port_id(struct platform_device *pdev,
struct s3c64xx_spi_driver_data *sdd)
{
+ const struct s3c64xx_spi_port_config *port_conf = sdd->port_conf;
int ret;

+ if (port_conf->rx_fifomask && port_conf->tx_fifomask)
+ return 0;
+
if (pdev->dev.of_node) {
ret = of_alias_get_id(pdev->dev.of_node, "spi");
if (ret < 0)
--
2.43.0.687.g38aa6559b0-goog


2024-02-12 14:11:58

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH v2 10/12] spi: s3c64xx: deprecate fifo_lvl_mask, rx_lvl_offset and port_id

Deprecate fifo_lvl_mask, rx_lvl_offset and port_id. One shall use
{rx, tx}_fifomask instead. Add messages to each port configuration.

Suggested-by: Sam Protsenko <[email protected]>
Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/spi/spi-s3c64xx.c | 26 +++++++++++++++++++++++---
1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index d2d1c9767145..128f4a7c4bd9 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -135,8 +135,8 @@ struct s3c64xx_spi_dma_data {

/**
* struct s3c64xx_spi_port_config - SPI Controller hardware info
- * @fifo_lvl_mask: Bit-mask for {TX|RX}_FIFO_LVL bits in SPI_STATUS register.
- * @rx_lvl_offset: Bit offset of RX_FIFO_LVL bits in SPI_STATUS regiter.
+ * @fifo_lvl_mask: [DEPRECATED] use @{rx, tx}_fifomask instead.
+ * @rx_lvl_offset: [DEPRECATED] use @{rx,tx}_fifomask instead.
* @fifo_depth: depth of the FIFO.
* @rx_fifomask: SPI_STATUS.RX_FIFO_LVL mask. Shifted mask defining the field's
* length and position.
@@ -192,7 +192,7 @@ struct s3c64xx_spi_port_config {
* @rx_dma: Local receive DMA data (e.g. chan and direction)
* @tx_dma: Local transmit DMA data (e.g. chan and direction)
* @port_conf: Local SPI port configuration data
- * @port_id: Port identification number
+ * @port_id: [DEPRECATED] use @{rx,tx}_fifomask instead.
* @fifo_depth: depth of the FIFO.
* @rx_fifomask: SPI_STATUS.RX_FIFO_LVL mask. Shifted mask defining the field's
* length and position.
@@ -1508,7 +1508,9 @@ static const struct dev_pm_ops s3c64xx_spi_pm = {
};

static const struct s3c64xx_spi_port_config s3c2443_spi_port_config = {
+ /* fifo_lvl_mask is deprecated. Use {rx, tx}_fifomask instead. */
.fifo_lvl_mask = { 0x7f },
+ /* rx_lvl_offset is deprecated. Use {rx, tx}_fifomask instead. */
.rx_lvl_offset = 13,
.tx_st_done = 21,
.clk_div = 2,
@@ -1516,14 +1518,18 @@ static const struct s3c64xx_spi_port_config s3c2443_spi_port_config = {
};

static const struct s3c64xx_spi_port_config s3c6410_spi_port_config = {
+ /* fifo_lvl_mask is deprecated. Use {rx, tx}_fifomask instead. */
.fifo_lvl_mask = { 0x7f, 0x7F },
+ /* rx_lvl_offset is deprecated. Use {rx, tx}_fifomask instead. */
.rx_lvl_offset = 13,
.tx_st_done = 21,
.clk_div = 2,
};

static const struct s3c64xx_spi_port_config s5pv210_spi_port_config = {
+ /* fifo_lvl_mask is deprecated. Use {rx, tx}_fifomask instead. */
.fifo_lvl_mask = { 0x1ff, 0x7F },
+ /* rx_lvl_offset is deprecated. Use {rx, tx}_fifomask instead. */
.rx_lvl_offset = 15,
.tx_st_done = 25,
.clk_div = 2,
@@ -1531,7 +1537,9 @@ static const struct s3c64xx_spi_port_config s5pv210_spi_port_config = {
};

static const struct s3c64xx_spi_port_config exynos4_spi_port_config = {
+ /* fifo_lvl_mask is deprecated. Use {rx, tx}_fifomask instead. */
.fifo_lvl_mask = { 0x1ff, 0x7F, 0x7F },
+ /* rx_lvl_offset is deprecated. Use {rx, tx}_fifomask instead. */
.rx_lvl_offset = 15,
.tx_st_done = 25,
.clk_div = 2,
@@ -1541,7 +1549,9 @@ static const struct s3c64xx_spi_port_config exynos4_spi_port_config = {
};

static const struct s3c64xx_spi_port_config exynos7_spi_port_config = {
+ /* fifo_lvl_mask is deprecated. Use {rx, tx}_fifomask instead. */
.fifo_lvl_mask = { 0x1ff, 0x7F, 0x7F, 0x7F, 0x7F, 0x1ff},
+ /* rx_lvl_offset is deprecated. Use {rx, tx}_fifomask instead. */
.rx_lvl_offset = 15,
.tx_st_done = 25,
.clk_div = 2,
@@ -1551,7 +1561,9 @@ static const struct s3c64xx_spi_port_config exynos7_spi_port_config = {
};

static const struct s3c64xx_spi_port_config exynos5433_spi_port_config = {
+ /* fifo_lvl_mask is deprecated. Use {rx, tx}_fifomask instead. */
.fifo_lvl_mask = { 0x1ff, 0x7f, 0x7f, 0x7f, 0x7f, 0x1ff},
+ /* rx_lvl_offset is deprecated. Use {rx, tx}_fifomask instead. */
.rx_lvl_offset = 15,
.tx_st_done = 25,
.clk_div = 2,
@@ -1562,7 +1574,9 @@ static const struct s3c64xx_spi_port_config exynos5433_spi_port_config = {
};

static const struct s3c64xx_spi_port_config exynos850_spi_port_config = {
+ /* fifo_lvl_mask is deprecated. Use {rx, tx}_fifomask instead. */
.fifo_lvl_mask = { 0x7f, 0x7f, 0x7f },
+ /* rx_lvl_offset is deprecated. Use {rx, tx}_fifomask instead. */
.rx_lvl_offset = 15,
.tx_st_done = 25,
.clk_div = 4,
@@ -1573,8 +1587,10 @@ static const struct s3c64xx_spi_port_config exynos850_spi_port_config = {
};

static const struct s3c64xx_spi_port_config exynosautov9_spi_port_config = {
+ /* fifo_lvl_mask is deprecated. Use {rx, tx}_fifomask instead. */
.fifo_lvl_mask = { 0x1ff, 0x1ff, 0x7f, 0x7f, 0x7f, 0x7f, 0x1ff, 0x7f,
0x7f, 0x7f, 0x7f, 0x7f},
+ /* rx_lvl_offset is deprecated. Use {rx, tx}_fifomask instead. */
.rx_lvl_offset = 15,
.tx_st_done = 25,
.clk_div = 4,
@@ -1586,7 +1602,9 @@ static const struct s3c64xx_spi_port_config exynosautov9_spi_port_config = {
};

static const struct s3c64xx_spi_port_config fsd_spi_port_config = {
+ /* fifo_lvl_mask is deprecated. Use {rx, tx}_fifomask instead. */
.fifo_lvl_mask = { 0x7f, 0x7f, 0x7f, 0x7f, 0x7f},
+ /* rx_lvl_offset is deprecated. Use {rx, tx}_fifomask instead. */
.rx_lvl_offset = 15,
.tx_st_done = 25,
.clk_div = 2,
@@ -1597,8 +1615,10 @@ static const struct s3c64xx_spi_port_config fsd_spi_port_config = {
};

static const struct s3c64xx_spi_port_config gs101_spi_port_config = {
+ /* fifo_lvl_mask is deprecated. Use {rx, tx}_fifomask instead. */
.fifo_lvl_mask = { 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f,
0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f},
+ /* rx_lvl_offset is deprecated. Use {rx, tx}_fifomask instead. */
.rx_lvl_offset = 15,
.tx_st_done = 25,
.clk_div = 4,
--
2.43.0.687.g38aa6559b0-goog


2024-02-12 14:12:04

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH v2 11/12] spi: s3c64xx: switch gs101 to new port config data

Drop the fifo_lvl_mask and rx_lvl_offset and switch to the new port
config data.

Advantages of the change:
- drop dependency on the OF alias ID.
- FIFO depth is inferred from the compatible. GS101 integrates 16 SPI
IPs, all with 64 bytes FIFO depths.
- use full mask for SPI_STATUS.{RX, TX}_FIFO_LVL fields. Using partial
masks is misleading and can hide problems of the driver logic.

S3C64XX_SPI_ST_TX_FIFO_RDY_V2 was defined based on the USI's
SPI_VERSION.USI_IP_VERSION register field, which has value 2 at reset.

MAX_SPI_PORTS is updated to reflect the maximum number of ports for the
rest of the compatibles.

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/spi/spi-s3c64xx.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 128f4a7c4bd9..784786407d2e 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -20,7 +20,7 @@
#include <linux/spi/spi.h>
#include <linux/types.h>

-#define MAX_SPI_PORTS 16
+#define MAX_SPI_PORTS 12
#define S3C64XX_SPI_QUIRK_CS_AUTO (1 << 1)
#define AUTOSUSPEND_TIMEOUT 2000

@@ -79,6 +79,8 @@
#define S3C64XX_SPI_INT_RX_FIFORDY_EN (1<<1)
#define S3C64XX_SPI_INT_TX_FIFORDY_EN (1<<0)

+#define S3C64XX_SPI_ST_RX_FIFO_RDY_V2 GENMASK(23, 15)
+#define S3C64XX_SPI_ST_TX_FIFO_RDY_V2 GENMASK(14, 6)
#define S3C64XX_SPI_ST_TX_FIFO_LVL_SHIFT 6
#define S3C64XX_SPI_ST_RX_OVERRUN_ERR (1<<5)
#define S3C64XX_SPI_ST_RX_UNDERRUN_ERR (1<<4)
@@ -1615,11 +1617,9 @@ static const struct s3c64xx_spi_port_config fsd_spi_port_config = {
};

static const struct s3c64xx_spi_port_config gs101_spi_port_config = {
- /* fifo_lvl_mask is deprecated. Use {rx, tx}_fifomask instead. */
- .fifo_lvl_mask = { 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f,
- 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f, 0x7f},
- /* rx_lvl_offset is deprecated. Use {rx, tx}_fifomask instead. */
- .rx_lvl_offset = 15,
+ .fifo_depth = 64,
+ .rx_fifomask = S3C64XX_SPI_ST_RX_FIFO_RDY_V2,
+ .tx_fifomask = S3C64XX_SPI_ST_TX_FIFO_RDY_V2,
.tx_st_done = 25,
.clk_div = 4,
.high_speed = true,
--
2.43.0.687.g38aa6559b0-goog


2024-02-12 14:12:28

by Tudor Ambarus

[permalink] [raw]
Subject: [PATCH v2 12/12] spi: s3c64xx: switch exynos850 to new port config data

Exynos850 has the same version of USI SPI (v2.1) as GS101.
Drop the fifo_lvl_mask and rx_lvl_offset and switch to the new port
config data.

Backward compatibility with DT is not broken because when alises are
set:
- the SPI core will set the bus number according to the alias ID
- the FIFO depth is always the same size for exynos850 (64 bytes) no
matter the alias ID number.

Advantages of the change:
- drop dependency on the OF alias ID.
- FIFO depth is inferred from the compatible. Exynos850 integrates 3 SPI
IPs, all with 64 bytes FIFO depths.
- use full mask for SPI_STATUS.{RX, TX}_FIFO_LVL fields. Using partial
masks is misleading and can hide problems of the driver logic.

Just compiled tested.

Signed-off-by: Tudor Ambarus <[email protected]>
---
drivers/spi/spi-s3c64xx.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 784786407d2e..9fcbe040cb2f 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -1576,10 +1576,9 @@ static const struct s3c64xx_spi_port_config exynos5433_spi_port_config = {
};

static const struct s3c64xx_spi_port_config exynos850_spi_port_config = {
- /* fifo_lvl_mask is deprecated. Use {rx, tx}_fifomask instead. */
- .fifo_lvl_mask = { 0x7f, 0x7f, 0x7f },
- /* rx_lvl_offset is deprecated. Use {rx, tx}_fifomask instead. */
- .rx_lvl_offset = 15,
+ .fifo_depth = 64,
+ .rx_fifomask = S3C64XX_SPI_ST_RX_FIFO_RDY_V2,
+ .tx_fifomask = S3C64XX_SPI_ST_TX_FIFO_RDY_V2,
.tx_st_done = 25,
.clk_div = 4,
.high_speed = true,
--
2.43.0.687.g38aa6559b0-goog


2024-02-12 15:44:37

by Rob Herring

[permalink] [raw]
Subject: Re: [PATCH v2 01/12] spi: dt-bindings: introduce FIFO depth properties


On Mon, 12 Feb 2024 14:03:20 +0000, Tudor Ambarus wrote:
> There are SPI IPs that can be configured by the integrator with a
> specific FIFO depth depending on the system's capabilities. For example,
> the samsung USI SPI IP can be configured by the integrator with a TX/RX
> FIFO from 8 byte to 256 bytes.
>
> Introduce the ``fifo-depth`` property for such instances of IPs where the
> same FIFO depth is used for both RX and TX. Introduce ``rx-fifo-depth``
> and ``tx-fifo-depth`` properties for cases where the RX FIFO depth is
> different from the TX FIFO depth.
>
> Make the dedicated RX/TX properties dependent on each other and mutual
> exclusive with the other.
>
> Signed-off-by: Tudor Ambarus <[email protected]>
> ---
> .../bindings/spi/spi-controller.yaml | 27 +++++++++++++++++++
> 1 file changed, 27 insertions(+)
>

My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check'
on your patch (DT_CHECKER_FLAGS is new in v5.13):

yamllint warnings/errors:
/Documentation/devicetree/bindings/spi/spi-controller.yaml:152:9: [warning] wrong indentation: expected 6 but found 8 (indentation)
/Documentation/devicetree/bindings/spi/spi-controller.yaml:156:9: [warning] wrong indentation: expected 6 but found 8 (indentation)

dtschema/dtc warnings/errors:

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/[email protected]

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.


2024-02-13 08:16:40

by Tudor Ambarus

[permalink] [raw]
Subject: Re: [PATCH v2 01/12] spi: dt-bindings: introduce FIFO depth properties



On 12.02.2024 17:36, Rob Herring wrote:
> My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check'
> on your patch (DT_CHECKER_FLAGS is new in v5.13):
>
> yamllint warnings/errors:
> ./Documentation/devicetree/bindings/spi/spi-controller.yaml:152:9:
> [warning] wrong indentation: expected 6 but found 8 (indentation)
> ./Documentation/devicetree/bindings/spi/spi-controller.yaml:156:9:
> [warning] wrong indentation: expected 6 but found 8 (indentation)
>
> dtschema/dtc warnings/errors:

oh, the horror, I missed these. I'll re-check and resend.

Thanks,
ta

2024-02-13 13:33:44

by Rob Herring

[permalink] [raw]
Subject: Re: [PATCH v2 01/12] spi: dt-bindings: introduce FIFO depth properties

On Mon, Feb 12, 2024 at 02:03:20PM +0000, Tudor Ambarus wrote:
> There are SPI IPs that can be configured by the integrator with a
> specific FIFO depth depending on the system's capabilities. For example,
> the samsung USI SPI IP can be configured by the integrator with a TX/RX
> FIFO from 8 byte to 256 bytes.
>
> Introduce the ``fifo-depth`` property for such instances of IPs where the
> same FIFO depth is used for both RX and TX. Introduce ``rx-fifo-depth``
> and ``tx-fifo-depth`` properties for cases where the RX FIFO depth is
> different from the TX FIFO depth.
>
> Make the dedicated RX/TX properties dependent on each other and mutual
> exclusive with the other.
>
> Signed-off-by: Tudor Ambarus <[email protected]>
> ---
> .../bindings/spi/spi-controller.yaml | 27 +++++++++++++++++++
> 1 file changed, 27 insertions(+)

With the indentation fixed,

Reviewed-by: Rob Herring <[email protected]>

2024-02-16 07:42:41

by kernel test robot

[permalink] [raw]
Subject: Re: [PATCH v2 01/12] spi: dt-bindings: introduce FIFO depth properties

Hi Tudor,

kernel test robot noticed the following build warnings:

[auto build test WARNING on broonie-spi/for-next]
[also build test WARNING on robh/for-next linus/master v6.8-rc4 next-20240216]
[cannot apply to krzk/for-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Tudor-Ambarus/spi-dt-bindings-introduce-FIFO-depth-properties/20240212-221427
base: https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next
patch link: https://lore.kernel.org/r/20240212140331.915498-2-tudor.ambarus%40linaro.org
patch subject: [PATCH v2 01/12] spi: dt-bindings: introduce FIFO depth properties
compiler: loongarch64-linux-gcc (GCC) 13.2.0
reproduce: (https://download.01.org/0day-ci/archive/20240216/[email protected]/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/

dtcheck warnings: (new ones prefixed by >>)
>> Documentation/devicetree/bindings/spi/spi-controller.yaml:152:9: [warning] wrong indentation: expected 6 but found 8 (indentation)
Documentation/devicetree/bindings/spi/spi-controller.yaml:156:9: [warning] wrong indentation: expected 6 but found 8 (indentation)

vim +152 Documentation/devicetree/bindings/spi/spi-controller.yaml

8
9 maintainers:
10 - Mark Brown <[email protected]>
11
12 description: |
13 SPI busses can be described with a node for the SPI controller device
14 and a set of child nodes for each SPI slave on the bus. The system SPI
15 controller may be described for use in SPI master mode or in SPI slave mode,
16 but not for both at the same time.
17
18 properties:
19 $nodename:
20 pattern: "^spi(@.*|-([0-9]|[1-9][0-9]+))?$"
21
22 "#address-cells":
23 enum: [0, 1]
24
25 "#size-cells":
26 const: 0
27
28 cs-gpios:
29 description: |
30 GPIOs used as chip selects.
31 If that property is used, the number of chip selects will be
32 increased automatically with max(cs-gpios, hardware chip selects).
33
34 So if, for example, the controller has 4 CS lines, and the
35 cs-gpios looks like this
36 cs-gpios = <&gpio1 0 0>, <0>, <&gpio1 1 0>, <&gpio1 2 0>;
37
38 Then it should be configured so that num_chipselect = 4, with
39 the following mapping
40 cs0 : &gpio1 0 0
41 cs1 : native
42 cs2 : &gpio1 1 0
43 cs3 : &gpio1 2 0
44
45 The second flag of a gpio descriptor can be GPIO_ACTIVE_HIGH (0)
46 or GPIO_ACTIVE_LOW(1). Legacy device trees often use 0.
47
48 There is a special rule set for combining the second flag of an
49 cs-gpio with the optional spi-cs-high flag for SPI slaves.
50
51 Each table entry defines how the CS pin is to be physically
52 driven (not considering potential gpio inversions by pinmux):
53
54 device node | cs-gpio | CS pin state active | Note
55 ================+===============+=====================+=====
56 spi-cs-high | - | H |
57 - | - | L |
58 spi-cs-high | ACTIVE_HIGH | H |
59 - | ACTIVE_HIGH | L | 1
60 spi-cs-high | ACTIVE_LOW | H | 2
61 - | ACTIVE_LOW | L |
62
63 Notes:
64 1) Should print a warning about polarity inversion.
65 Here it would be wise to avoid and define the gpio as
66 ACTIVE_LOW.
67 2) Should print a warning about polarity inversion
68 because ACTIVE_LOW is overridden by spi-cs-high.
69 Should be generally avoided and be replaced by
70 spi-cs-high + ACTIVE_HIGH.
71
72 fifo-depth:
73 $ref: /schemas/types.yaml#/definitions/uint32
74 description:
75 Size of the RX and TX data FIFOs in bytes.
76
77 rx-fifo-depth:
78 $ref: /schemas/types.yaml#/definitions/uint32
79 description:
80 Size of the RX data FIFO in bytes.
81
82 tx-fifo-depth:
83 $ref: /schemas/types.yaml#/definitions/uint32
84 description:
85 Size of the TX data FIFO in bytes.
86
87 num-cs:
88 $ref: /schemas/types.yaml#/definitions/uint32
89 description:
90 Total number of chip selects.
91
92 spi-slave:
93 $ref: /schemas/types.yaml#/definitions/flag
94 description:
95 The SPI controller acts as a slave, instead of a master.
96
97 slave:
98 type: object
99
100 properties:
101 compatible:
102 description:
103 Compatible of the SPI device.
104
105 required:
106 - compatible
107
108 patternProperties:
109 "^.*@[0-9a-f]+$":
110 type: object
111 $ref: spi-peripheral-props.yaml
112 additionalProperties: true
113
114 properties:
115 spi-3wire:
116 $ref: /schemas/types.yaml#/definitions/flag
117 description:
118 The device requires 3-wire mode.
119
120 spi-cpha:
121 $ref: /schemas/types.yaml#/definitions/flag
122 description:
123 The device requires shifted clock phase (CPHA) mode.
124
125 spi-cpol:
126 $ref: /schemas/types.yaml#/definitions/flag
127 description:
128 The device requires inverse clock polarity (CPOL) mode.
129
130 required:
131 - compatible
132 - reg
133
134 dependencies:
135 rx-fifo-depth: [ tx-fifo-depth ]
136 tx-fifo-depth: [ rx-fifo-depth ]
137
138 allOf:
139 - if:
140 not:
141 required:
142 - spi-slave
143 then:
144 properties:
145 "#address-cells":
146 const: 1
147 else:
148 properties:
149 "#address-cells":
150 const: 0
151 - not:
> 152 required:
153 - fifo-depth
154 - rx-fifo-depth
155 - not:
156 required:
157 - fifo-depth
158 - tx-fifo-depth
159

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https://github.com/intel/lkp-tests/wiki