[PATCH v3 0/3] Altera Cyclone Passive Serial SPI FPGA Manager

[PATCH v3 0/3] Altera Cyclone Passive Serial SPI FPGA Manager

[Joshua Clayton]

This series adds an FPGA manager for Altera cyclone FPGAs
that can program them using an spi port and a couple of gpios, using
Alteras passive serial protocol.

Changes from v2:

- Merged patch 3 and 4 as suggested in review by Moritz Fischer
- Changed FPGA_MIN_DELAY from 250 to 50 ms is the time advertized by
  Altera. This now works, as we don't assume it is done

Changes from v1:
- Changed the name from cyclone-spi-fpga-mgr to cyclone-ps-spi-fpga-mgr
  This name change was requested by Alan Tull, to be specific about which
  programming method is being employed on the fpga.
- Changed the name of the reset-gpio to config-gpio to closer match the
  way the pins are described in the Altera manual
- Moved MODULE_LICENCE, _AUTHOR, and _DESCRIPTION to the bottom

- Added a bitrev8x4() function to the bitrev headers and implemented ARM
 const, runtime, and ARM specific faster versions (This may end up
 needing to be a standalone patch)

- Moved the bitswapping into cyclonespi_write(), as requested.
  This falls short of my desired generic lsb first spi support, but is a step
  in that direction.

- Fixed whitespace problems introduced during refactoring

- Replaced magic number for initial delay with a descriptive macro
- Poll the fpga to see when it is ready rather than a fixed 1 ms sleep

Joshua Clayton (3):
  lib: add bitrev8x4()
  doc: dt: add cyclone-spi binding document
  fpga manager: Add cyclone-ps-spi driver for Altera FPGAs

 .../bindings/fpga/cyclone-ps-spi-fpga-mgr.txt      |  23 +++
 arch/arm/include/asm/bitrev.h                      |   5 +
 drivers/fpga/Kconfig                               |   7 +
 drivers/fpga/Makefile                              |   1 +
 drivers/fpga/cyclone-ps-spi.c                      | 176 +++++++++++++++++++++
 include/linux/bitrev.h                             |  26 +++
 6 files changed, 238 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/fpga/cyclone-ps-spi-fpga-mgr.txt
 create mode 100644 drivers/fpga/cyclone-ps-spi.c

-- 
2.9.3

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[PATCH v3 1/3] lib: add bitrev8x4()

[Joshua Clayton]

Add a function to reverse bytes within a 32 bit word.
This function is more efficient than using the 8 bit version when
iterating over an array

Signed-off-by: Joshua Clayton <stillcompiling-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 arch/arm/include/asm/bitrev.h |  5 +++++
 include/linux/bitrev.h        | 26 ++++++++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/arch/arm/include/asm/bitrev.h b/arch/arm/include/asm/bitrev.h
index ec291c3..6d2e9ca 100644
--- a/arch/arm/include/asm/bitrev.h
+++ b/arch/arm/include/asm/bitrev.h
@@ -17,4 +17,9 @@ static __always_inline __attribute_const__ u8 __arch_bitrev8(u8 x)
 	return __arch_bitrev32((u32)x) >> 24;
 }
 
+static __always_inline __attribute_const__ u32 __arch_bitrev8x4(u32 x)
+{
+	__asm__ ("rbit %0, %1; rev %0, %0" : "=r" (x) : "r" (x));
+}
+
 #endif
diff --git a/include/linux/bitrev.h b/include/linux/bitrev.h
index fb790b8..b1cfa1a 100644
--- a/include/linux/bitrev.h
+++ b/include/linux/bitrev.h
@@ -9,6 +9,7 @@
 #define __bitrev32 __arch_bitrev32
 #define __bitrev16 __arch_bitrev16
 #define __bitrev8 __arch_bitrev8
+#define __bitrev8x4 __arch_bitrev8x4
 
 #else
 extern u8 const byte_rev_table[256];
@@ -27,6 +28,14 @@ static inline u32 __bitrev32(u32 x)
 	return (__bitrev16(x & 0xffff) << 16) | __bitrev16(x >> 16);
 }
 
+static inline u32 __bitrev8x4(u32 x)
+{
+	return(__bitrev8(x & 0xff) |
+	       (__bitrev8((x >> 8)  & 0xff) << 8) |
+	       (__bitrev8((x >> 16)  & 0xff) << 16) |
+	       (__bitrev8((x >> 24)  & 0xff) << 24));
+}
+
 #endif /* CONFIG_HAVE_ARCH_BITREVERSE */
 
 #define __constant_bitrev32(x)	\
@@ -50,6 +59,15 @@ static inline u32 __bitrev32(u32 x)
 	__x;								\
 })
 
+#define __constant_bitrev8x4(x) \
+({			\
+	u32 __x = x;	\
+	__x = ((__x & (u32)0xF0F0F0F0UL) >> 4) | ((__x & (u32)0x0F0F0F0FUL) << 4);	\
+	__x = ((__x & (u32)0xCCCCCCCCUL) >> 2) | ((__x & (u32)0x33333333UL) << 2);	\
+	__x = ((__x & (u32)0xAAAAAAAAUL) >> 1) | ((__x & (u32)0x55555555UL) << 1);	\
+	__x;								\
+})
+
 #define __constant_bitrev8(x)	\
 ({					\
 	u8 __x = x;			\
@@ -75,6 +93,14 @@ static inline u32 __bitrev32(u32 x)
 	__bitrev16(__x);				\
  })
 
+#define bitrev8x4(x) \
+({			\
+	u32 __x = x;	\
+	__builtin_constant_p(__x) ?	\
+	__constant_bitrev8x4(__x) :			\
+	__bitrev8x4(__x);				\
+})
+
 #define bitrev8(x) \
 ({			\
 	u8 __x = x;	\
-- 
2.9.3

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[PATCH v3 2/3] doc: dt: add cyclone-spi binding document

[Joshua Clayton]

Describe a cyclonei-ps-spi devicetree entry, required features

Signed-off-by: Joshua Clayton <stillcompiling-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 .../bindings/fpga/cyclone-ps-spi-fpga-mgr.txt      | 23 ++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/fpga/cyclone-ps-spi-fpga-mgr.txt

diff --git a/Documentation/devicetree/bindings/fpga/cyclone-ps-spi-fpga-mgr.txt b/Documentation/devicetree/bindings/fpga/cyclone-ps-spi-fpga-mgr.txt
new file mode 100644
index 0000000..c942281
--- /dev/null
+++ b/Documentation/devicetree/bindings/fpga/cyclone-ps-spi-fpga-mgr.txt
@@ -0,0 +1,23 @@
+Altera Cyclone Passive Serial SPI FPGA Manager
+
+Altera Cyclone FPGAs support a method of loading the bitstream over what is
+referred to as "passive serial".
+The passive serial link is not technically spi, and might require extra
+circuits in order to play nicely with other spi slaves on the same bus.
+
+See https://www.altera.com/literature/hb/cyc/cyc_c51013.pdf
+
+Required properties:
+- compatible  : should contain "altr,cyclone-ps-spi-fpga-mgr"
+- reg         : spi slave id of the fpga
+- config-gpio : config pin (referred to as nCONFIG in the cyclone manual)
+- status-gpio : status pin (referred to as nSTATUS in the cyclone manual)
+
+Example:
+	fpga_spi: evi-fpga-spi@0 {
+		compatible = "altr,cyclone-ps-spi-fpga-mgr";
+		spi-max-frequency = <20000000>;
+		reg = <0>;
+		config-gpio = <&gpio4 9 GPIO_ACTIVE_HIGH>;
+		status-gpio = <&gpio4 11 GPIO_ACTIVE_HIGH>;
+	};
-- 
2.9.3

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[PATCH v3 3/3] fpga manager: Add cyclone-ps-spi driver for Altera FPGAs

[Joshua Clayton]

cyclone-ps-spi loads FPGA firmware over spi, using the "passive serial"
interface on Altera Cyclone FPGAS.

This is one of the simpler ways to set up an FPGA at runtime.
The signal interface is close to unidirectional spi with lsb first.

Signed-off-by: Joshua Clayton <stillcompiling-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 drivers/fpga/Kconfig          |   7 ++
 drivers/fpga/Makefile         |   1 +
 drivers/fpga/cyclone-ps-spi.c | 176 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 184 insertions(+)
 create mode 100644 drivers/fpga/cyclone-ps-spi.c

diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index cd84934..2462707 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -13,6 +13,13 @@ config FPGA
 
 if FPGA
 
+config FPGA_MGR_CYCLONE_PS_SPI
+	tristate "Altera Cyclone FPGA Passive Serial over SPI"
+	depends on SPI
+	help
+	  FPGA manager driver support for Altera Cyclone using the
+	  passive serial interface over SPI
+
 config FPGA_MGR_SOCFPGA
 	tristate "Altera SOCFPGA FPGA Manager"
 	depends on ARCH_SOCFPGA
diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
index 8d83fc6..8f93930 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -6,5 +6,6 @@
 obj-$(CONFIG_FPGA)			+= fpga-mgr.o
 
 # FPGA Manager Drivers
+obj-$(CONFIG_FPGA_MGR_CYCLONE_PS_SPI)	+= cyclone-ps-spi.o
 obj-$(CONFIG_FPGA_MGR_SOCFPGA)		+= socfpga.o
 obj-$(CONFIG_FPGA_MGR_ZYNQ_FPGA)	+= zynq-fpga.o
diff --git a/drivers/fpga/cyclone-ps-spi.c b/drivers/fpga/cyclone-ps-spi.c
new file mode 100644
index 0000000..57a520d
--- /dev/null
+++ b/drivers/fpga/cyclone-ps-spi.c
@@ -0,0 +1,176 @@
+/**
+ * Copyright (c) 2015 United Western Technologies, Corporation
+ *
+ * Joshua Clayton <stillcompiling-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
+ *
+ * Manage Altera fpga firmware that is loaded over spi.
+ * Firmware must be in binary "rbf" format.
+ * Works on Cyclone V. Should work on cyclone series.
+ * May work on other Altera fpgas.
+ *
+ */
+
+#include <linux/bitrev.h>
+#include <linux/delay.h>
+#include <linux/fpga/fpga-mgr.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+#include <linux/spi/spi.h>
+#include <linux/sizes.h>
+
+#define FPGA_RESET_TIME		50   /* time in usecs to trigger FPGA config */
+#define FPGA_MIN_DELAY		50   /* min usecs to wait for config status */
+#define FPGA_MAX_DELAY		1000 /* max usecs to wait for config status */
+
+struct cyclonespi_conf {
+	struct gpio_desc *config;
+	struct gpio_desc *status;
+	struct spi_device *spi;
+};
+
+static const struct of_device_id of_ef_match[] = {
+	{ .compatible = "altr,cyclone-ps-spi-fpga-mgr", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, of_ef_match);
+
+static enum fpga_mgr_states cyclonespi_state(struct fpga_manager *mgr)
+{
+	return mgr->state;
+}
+
+static int cyclonespi_write_init(struct fpga_manager *mgr, u32 flags,
+				 const char *buf, size_t count)
+{
+	struct cyclonespi_conf *conf = (struct cyclonespi_conf *)mgr->priv;
+	int i;
+
+	if (flags & FPGA_MGR_PARTIAL_RECONFIG) {
+		dev_err(&mgr->dev, "Partial reconfiguration not supported.\n");
+		return -EINVAL;
+	}
+
+	gpiod_set_value(conf->config, 0);
+	usleep_range(FPGA_RESET_TIME, FPGA_RESET_TIME + 20);
+	if (gpiod_get_value(conf->status) == 1) {
+		dev_err(&mgr->dev, "Status pin should be low.\n");
+		return -EIO;
+	}
+
+	gpiod_set_value(conf->config, 1);
+	for (i = 0; i < (FPGA_MAX_DELAY / FPGA_MIN_DELAY); i++) {
+		usleep_range(FPGA_MIN_DELAY, FPGA_MIN_DELAY + 20);
+		if (gpiod_get_value(conf->status))
+			return 0;
+	}
+
+	dev_err(&mgr->dev, "Status pin not ready.\n");
+	return -EIO;
+}
+
+static void rev_buf(void *buf, size_t len)
+{
+	u32 *fw32 = (u32 *)buf;
+	const u32 *fw_end = (u32 *)(buf + len);
+
+	/* set buffer to lsb first */
+	while (fw32 < fw_end) {
+		*fw32 = bitrev8x4(*fw32);
+		fw32++;
+	}
+}
+
+static int cyclonespi_write(struct fpga_manager *mgr, const char *buf,
+			    size_t count)
+{
+	struct cyclonespi_conf *conf = (struct cyclonespi_conf *)mgr->priv;
+	const char *fw_data = buf;
+	const char *fw_data_end = fw_data + count;
+
+	while (fw_data < fw_data_end) {
+		int ret;
+		size_t stride = min(fw_data_end - fw_data, SZ_4K);
+
+		rev_buf((void *)fw_data, stride);
+		ret = spi_write(conf->spi, fw_data, stride);
+		if (ret) {
+			dev_err(&mgr->dev, "spi error in firmware write: %d\n",
+				ret);
+			return ret;
+		}
+		fw_data += stride;
+	}
+
+	return 0;
+}
+
+static int cyclonespi_write_complete(struct fpga_manager *mgr, u32 flags)
+{
+	struct cyclonespi_conf *conf = (struct cyclonespi_conf *)mgr->priv;
+
+	if (gpiod_get_value(conf->status) == 0) {
+		dev_err(&mgr->dev, "Error during configuration.\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static const struct fpga_manager_ops cyclonespi_ops = {
+	.state = cyclonespi_state,
+	.write_init = cyclonespi_write_init,
+	.write = cyclonespi_write,
+	.write_complete = cyclonespi_write_complete,
+};
+
+static int cyclonespi_probe(struct spi_device *spi)
+{
+	struct cyclonespi_conf *conf = devm_kzalloc(&spi->dev, sizeof(*conf),
+						GFP_KERNEL);
+
+	if (!conf)
+		return -ENOMEM;
+
+	conf->spi = spi;
+	conf->config = devm_gpiod_get(&spi->dev, "config", GPIOD_OUT_LOW);
+	if (IS_ERR(conf->config)) {
+		dev_err(&spi->dev, "Failed to get config gpio: %ld\n",
+			PTR_ERR(conf->config));
+		return PTR_ERR(conf->config);
+	}
+
+	conf->status = devm_gpiod_get(&spi->dev, "status", GPIOD_IN);
+	if (IS_ERR(conf->status)) {
+		dev_err(&spi->dev, "Failed to get status gpio: %ld\n",
+			PTR_ERR(conf->status));
+		return PTR_ERR(conf->status);
+	}
+
+	return fpga_mgr_register(&spi->dev,
+				 "Altera Cyclone PS SPI FPGA Manager",
+				 &cyclonespi_ops, conf);
+}
+
+static int cyclonespi_remove(struct spi_device *spi)
+{
+	fpga_mgr_unregister(&spi->dev);
+
+	return 0;
+}
+
+static struct spi_driver cyclonespi_driver = {
+	.driver = {
+		.name   = "cyclone-ps-spi",
+		.owner  = THIS_MODULE,
+		.of_match_table = of_match_ptr(of_ef_match),
+	},
+	.probe  = cyclonespi_probe,
+	.remove = cyclonespi_remove,
+};
+
+module_spi_driver(cyclonespi_driver)
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Joshua Clayton <stillcompiling-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>");
+MODULE_DESCRIPTION("Module to load Altera FPGA firmware over spi");
-- 
2.9.3

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Re: [PATCH v3 3/3] fpga manager: Add cyclone-ps-spi driver for Altera FPGAs

[atull]

On Wed, 30 Nov 2016, Joshua Clayton wrote:

Hi Clayton,

I just have a few minor one line changes below.  Only one
is operational, I should have caught that earlier.

> cyclone-ps-spi loads FPGA firmware over spi, using the "passive serial"
> interface on Altera Cyclone FPGAS.
> 
> This is one of the simpler ways to set up an FPGA at runtime.
> The signal interface is close to unidirectional spi with lsb first.
> 
> Signed-off-by: Joshua Clayton <stillcompiling@gmail.com>
> ---
>  drivers/fpga/Kconfig          |   7 ++
>  drivers/fpga/Makefile         |   1 +
>  drivers/fpga/cyclone-ps-spi.c | 176 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 184 insertions(+)
>  create mode 100644 drivers/fpga/cyclone-ps-spi.c
> 
> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> index cd84934..2462707 100644
> --- a/drivers/fpga/Kconfig
> +++ b/drivers/fpga/Kconfig
> @@ -13,6 +13,13 @@ config FPGA
>  
>  if FPGA
>  
> +config FPGA_MGR_CYCLONE_PS_SPI
> +	tristate "Altera Cyclone FPGA Passive Serial over SPI"
> +	depends on SPI
> +	help
> +	  FPGA manager driver support for Altera Cyclone using the
> +	  passive serial interface over SPI
> +
>  config FPGA_MGR_SOCFPGA
>  	tristate "Altera SOCFPGA FPGA Manager"
>  	depends on ARCH_SOCFPGA
> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> index 8d83fc6..8f93930 100644
> --- a/drivers/fpga/Makefile
> +++ b/drivers/fpga/Makefile
> @@ -6,5 +6,6 @@
>  obj-$(CONFIG_FPGA)			+= fpga-mgr.o
>  
>  # FPGA Manager Drivers
> +obj-$(CONFIG_FPGA_MGR_CYCLONE_PS_SPI)	+= cyclone-ps-spi.o
>  obj-$(CONFIG_FPGA_MGR_SOCFPGA)		+= socfpga.o
>  obj-$(CONFIG_FPGA_MGR_ZYNQ_FPGA)	+= zynq-fpga.o
> diff --git a/drivers/fpga/cyclone-ps-spi.c b/drivers/fpga/cyclone-ps-spi.c
> new file mode 100644
> index 0000000..57a520d
> --- /dev/null
> +++ b/drivers/fpga/cyclone-ps-spi.c
> @@ -0,0 +1,176 @@
> +/**
> + * Copyright (c) 2015 United Western Technologies, Corporation
> + *
> + * Joshua Clayton <stillcompiling@gmail.com>
> + *
> + * Manage Altera fpga firmware that is loaded over spi.
> + * Firmware must be in binary "rbf" format.
> + * Works on Cyclone V. Should work on cyclone series.
> + * May work on other Altera fpgas.
> + *
> + */
> +
> +#include <linux/bitrev.h>
> +#include <linux/delay.h>
> +#include <linux/fpga/fpga-mgr.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/module.h>
> +#include <linux/of_gpio.h>
> +#include <linux/spi/spi.h>
> +#include <linux/sizes.h>
> +
> +#define FPGA_RESET_TIME		50   /* time in usecs to trigger FPGA config */
> +#define FPGA_MIN_DELAY		50   /* min usecs to wait for config status */
> +#define FPGA_MAX_DELAY		1000 /* max usecs to wait for config status */
> +
> +struct cyclonespi_conf {
> +	struct gpio_desc *config;
> +	struct gpio_desc *status;
> +	struct spi_device *spi;
> +};
> +
> +static const struct of_device_id of_ef_match[] = {
> +	{ .compatible = "altr,cyclone-ps-spi-fpga-mgr", },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, of_ef_match);
> +
> +static enum fpga_mgr_states cyclonespi_state(struct fpga_manager *mgr)
> +{
> +	return mgr->state;
> +}

This function gets called once to initialize mgr->state in
fpga_mgr_register().  So it should at least return the state the FPGA
is at then.  If it is unknown, it can just return
FPGA_MGR_STATE_UNKNOWN.

> +
> +static int cyclonespi_write_init(struct fpga_manager *mgr, u32 flags,
> +				 const char *buf, size_t count)

Minor, but please fix the indentation of 'const' to match that of
'struct' above.  checkpatch.pl is probably issuing warnings
about that.

> +{
> +	struct cyclonespi_conf *conf = (struct cyclonespi_conf *)mgr->priv;
> +	int i;
> +
> +	if (flags & FPGA_MGR_PARTIAL_RECONFIG) {
> +		dev_err(&mgr->dev, "Partial reconfiguration not supported.\n");
> +		return -EINVAL;
> +	}
> +
> +	gpiod_set_value(conf->config, 0);
> +	usleep_range(FPGA_RESET_TIME, FPGA_RESET_TIME + 20);
> +	if (gpiod_get_value(conf->status) == 1) {
> +		dev_err(&mgr->dev, "Status pin should be low.\n");
> +		return -EIO;
> +	}
> +
> +	gpiod_set_value(conf->config, 1);
> +	for (i = 0; i < (FPGA_MAX_DELAY / FPGA_MIN_DELAY); i++) {
> +		usleep_range(FPGA_MIN_DELAY, FPGA_MIN_DELAY + 20);
> +		if (gpiod_get_value(conf->status))
> +			return 0;
> +	}
> +
> +	dev_err(&mgr->dev, "Status pin not ready.\n");
> +	return -EIO;
> +}
> +
> +static void rev_buf(void *buf, size_t len)
> +{
> +	u32 *fw32 = (u32 *)buf;
> +	const u32 *fw_end = (u32 *)(buf + len);
> +
> +	/* set buffer to lsb first */
> +	while (fw32 < fw_end) {
> +		*fw32 = bitrev8x4(*fw32);
> +		fw32++;
> +	}
> +}
> +
> +static int cyclonespi_write(struct fpga_manager *mgr, const char *buf,
> +			    size_t count)

Please fix alignment here also.

> +{
> +	struct cyclonespi_conf *conf = (struct cyclonespi_conf *)mgr->priv;
> +	const char *fw_data = buf;
> +	const char *fw_data_end = fw_data + count;
> +
> +	while (fw_data < fw_data_end) {
> +		int ret;
> +		size_t stride = min(fw_data_end - fw_data, SZ_4K);
> +
> +		rev_buf((void *)fw_data, stride);
> +		ret = spi_write(conf->spi, fw_data, stride);
> +		if (ret) {
> +			dev_err(&mgr->dev, "spi error in firmware write: %d\n",
> +				ret);
> +			return ret;
> +		}
> +		fw_data += stride;
> +	}
> +
> +	return 0;
> +}
> +
> +static int cyclonespi_write_complete(struct fpga_manager *mgr, u32 flags)
> +{
> +	struct cyclonespi_conf *conf = (struct cyclonespi_conf *)mgr->priv;
> +
> +	if (gpiod_get_value(conf->status) == 0) {
> +		dev_err(&mgr->dev, "Error during configuration.\n");
> +		return -EIO;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct fpga_manager_ops cyclonespi_ops = {
> +	.state = cyclonespi_state,
> +	.write_init = cyclonespi_write_init,
> +	.write = cyclonespi_write,
> +	.write_complete = cyclonespi_write_complete,
> +};
> +
> +static int cyclonespi_probe(struct spi_device *spi)
> +{
> +	struct cyclonespi_conf *conf = devm_kzalloc(&spi->dev, sizeof(*conf),
> +						GFP_KERNEL);
> +
> +	if (!conf)
> +		return -ENOMEM;
> +
> +	conf->spi = spi;
> +	conf->config = devm_gpiod_get(&spi->dev, "config", GPIOD_OUT_LOW);
> +	if (IS_ERR(conf->config)) {
> +		dev_err(&spi->dev, "Failed to get config gpio: %ld\n",
> +			PTR_ERR(conf->config));
> +		return PTR_ERR(conf->config);
> +	}
> +
> +	conf->status = devm_gpiod_get(&spi->dev, "status", GPIOD_IN);
> +	if (IS_ERR(conf->status)) {
> +		dev_err(&spi->dev, "Failed to get status gpio: %ld\n",
> +			PTR_ERR(conf->status));
> +		return PTR_ERR(conf->status);
> +	}
> +
> +	return fpga_mgr_register(&spi->dev,
> +				 "Altera Cyclone PS SPI FPGA Manager",
> +				 &cyclonespi_ops, conf);
> +}
> +
> +static int cyclonespi_remove(struct spi_device *spi)
> +{
> +	fpga_mgr_unregister(&spi->dev);
> +
> +	return 0;
> +}
> +
> +static struct spi_driver cyclonespi_driver = {
> +	.driver = {
> +		.name   = "cyclone-ps-spi",
> +		.owner  = THIS_MODULE,
> +		.of_match_table = of_match_ptr(of_ef_match),
> +	},
> +	.probe  = cyclonespi_probe,
> +	.remove = cyclonespi_remove,
> +};
> +
> +module_spi_driver(cyclonespi_driver)
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Joshua Clayton <stillcompiling@gmail.com>");
> +MODULE_DESCRIPTION("Module to load Altera FPGA firmware over spi");
> -- 
> 2.9.3
> 
> 

Thanks,
Alan

Re: [PATCH v3 3/3] fpga manager: Add cyclone-ps-spi driver for Altera FPGAs

[Joshua Clayton]

Hi Alan,

On 11/30/2016 09:45 AM, atull wrote:
> On Wed, 30 Nov 2016, Joshua Clayton wrote:
>
> Hi Clayton,
>
> I just have a few minor one line changes below.  Only one
> is operational, I should have caught that earlier.
>
Thanks for the speedy review.
>> +};
>> +MODULE_DEVICE_TABLE(of, of_ef_match);
>> +
>> +static enum fpga_mgr_states cyclonespi_state(struct fpga_manager *mgr)
>> +{
>> +	return mgr->state;
>> +}
> This function gets called once to initialize mgr->state in
> fpga_mgr_register().  So it should at least return the state the FPGA
> is at then.  If it is unknown, it can just return
> FPGA_MGR_STATE_UNKNOWN.
>
I guess I didn't understand the purpose of this function.
The driver has access to the status pin at this phase, so I can return
FPGA_MGR_STATE_UNKNOWN or FPGA_MGR_STATE_RESET depending
on the state of that pin.

>> +
>> +static int cyclonespi_write_init(struct fpga_manager *mgr, u32 flags,
>> +				 const char *buf, size_t count)
> Minor, but please fix the indentation of 'const' to match that of
> 'struct' above.  checkpatch.pl is probably issuing warnings
> about that.
I double checked. The indentation is correct here. It only has
The appearance of being off by one due to the diff format.
>> +{
>> +	struct cyclonespi_conf *conf = (struct cyclonespi_conf *)mgr->priv;
>> +	int i;
>> +
>> +	if (flags & FPGA_MGR_PARTIAL_RECONFIG) {
>> +		dev_err(&mgr->dev, "Partial reconfiguration not supported.\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	gpiod_set_value(conf->config, 0);
>> +	usleep_range(FPGA_RESET_TIME, FPGA_RESET_TIME + 20);
>> +	if (gpiod_get_value(conf->status) == 1) {
>> +		dev_err(&mgr->dev, "Status pin should be low.\n");
>> +		return -EIO;
>> +	}
>> +
>> +	gpiod_set_value(conf->config, 1);
>> +	for (i = 0; i < (FPGA_MAX_DELAY / FPGA_MIN_DELAY); i++) {
>> +		usleep_range(FPGA_MIN_DELAY, FPGA_MIN_DELAY + 20);
>> +		if (gpiod_get_value(conf->status))
>> +			return 0;
>> +	}
>> +
>> +	dev_err(&mgr->dev, "Status pin not ready.\n");
>> +	return -EIO;
>> +}
>> +
>> +static void rev_buf(void *buf, size_t len)
>> +{
>> +	u32 *fw32 = (u32 *)buf;
>> +	const u32 *fw_end = (u32 *)(buf + len);
>> +
>> +	/* set buffer to lsb first */
>> +	while (fw32 < fw_end) {
>> +		*fw32 = bitrev8x4(*fw32);
>> +		fw32++;
>> +	}
>> +}
>> +
>> +static int cyclonespi_write(struct fpga_manager *mgr, const char *buf,
>> +			    size_t count)
> Please fix alignment here also.
Same as above. Indentation is OK.


I'll get a v4 turned around soon.
Thanks,
Joshua
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Re: [PATCH v3 3/3] fpga manager: Add cyclone-ps-spi driver for Altera FPGAs

[atull]

On Wed, 30 Nov 2016, Joshua Clayton wrote:

Hi Joshua,

> Hi Alan,
> 
> On 11/30/2016 09:45 AM, atull wrote:
> > On Wed, 30 Nov 2016, Joshua Clayton wrote:
> >
> > Hi Clayton,
> >
> > I just have a few minor one line changes below.  Only one
> > is operational, I should have caught that earlier.
> >
> Thanks for the speedy review.
> >> +};
> >> +MODULE_DEVICE_TABLE(of, of_ef_match);
> >> +
> >> +static enum fpga_mgr_states cyclonespi_state(struct fpga_manager *mgr)
> >> +{
> >> +	return mgr->state;
> >> +}
> > This function gets called once to initialize mgr->state in
> > fpga_mgr_register().  So it should at least return the state the FPGA
> > is at then.  If it is unknown, it can just return
> > FPGA_MGR_STATE_UNKNOWN.
> >
> I guess I didn't understand the purpose of this function.
> The driver has access to the status pin at this phase, so I can return
> FPGA_MGR_STATE_UNKNOWN or FPGA_MGR_STATE_RESET depending
> on the state of that pin.
> 
> >> +
> >> +static int cyclonespi_write_init(struct fpga_manager *mgr, u32 flags,
> >> +				 const char *buf, size_t count)
> > Minor, but please fix the indentation of 'const' to match that of
> > 'struct' above.  checkpatch.pl is probably issuing warnings
> > about that.
> I double checked. The indentation is correct here. It only has
> The appearance of being off by one due to the diff format.

Yes, I understand.

> >> +{
> >> +	struct cyclonespi_conf *conf = (struct cyclonespi_conf *)mgr->priv;
> >> +	int i;
> >> +
> >> +	if (flags & FPGA_MGR_PARTIAL_RECONFIG) {
> >> +		dev_err(&mgr->dev, "Partial reconfiguration not supported.\n");
> >> +		return -EINVAL;
> >> +	}
> >> +
> >> +	gpiod_set_value(conf->config, 0);
> >> +	usleep_range(FPGA_RESET_TIME, FPGA_RESET_TIME + 20);
> >> +	if (gpiod_get_value(conf->status) == 1) {
> >> +		dev_err(&mgr->dev, "Status pin should be low.\n");
> >> +		return -EIO;
> >> +	}
> >> +
> >> +	gpiod_set_value(conf->config, 1);
> >> +	for (i = 0; i < (FPGA_MAX_DELAY / FPGA_MIN_DELAY); i++) {
> >> +		usleep_range(FPGA_MIN_DELAY, FPGA_MIN_DELAY + 20);
> >> +		if (gpiod_get_value(conf->status))
> >> +			return 0;
> >> +	}
> >> +
> >> +	dev_err(&mgr->dev, "Status pin not ready.\n");
> >> +	return -EIO;
> >> +}
> >> +
> >> +static void rev_buf(void *buf, size_t len)
> >> +{
> >> +	u32 *fw32 = (u32 *)buf;
> >> +	const u32 *fw_end = (u32 *)(buf + len);
> >> +
> >> +	/* set buffer to lsb first */
> >> +	while (fw32 < fw_end) {
> >> +		*fw32 = bitrev8x4(*fw32);
> >> +		fw32++;
> >> +	}
> >> +}
> >> +
> >> +static int cyclonespi_write(struct fpga_manager *mgr, const char *buf,
> >> +			    size_t count)
> > Please fix alignment here also.
> Same as above. Indentation is OK.
> 
> 
> I'll get a v4 turned around soon.

No rush since the other two patches need acks from
their respective maintainers and this won't be able
to go in without them.  But with that one change
it looks good to me.

Alan

> Thanks,
> Joshua
> 

Re: [PATCH v3 3/3] fpga manager: Add cyclone-ps-spi driver for Altera FPGAs

[kbuild test robot]

Hi Joshua,

[auto build test WARNING on linus/master]
[also build test WARNING on v4.9-rc7]
[cannot apply to next-20161201]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Joshua-Clayton/lib-add-bitrev8x4/20161202-013521
reproduce:
        # apt-get install sparse
        make ARCH=x86_64 allmodconfig
        make C=1 CF=-D__CHECK_ENDIAN__


sparse warnings: (new ones prefixed by >>)

   include/linux/compiler.h:253:8: sparse: attribute 'no_sanitize_address': unknown attribute
>> drivers/fpga/cyclone-ps-spi.c:93:33: sparse: incompatible types in comparison expression (different type sizes)
   In file included from include/linux/delay.h:10:0,
                    from drivers/fpga/cyclone-ps-spi.c:14:
   drivers/fpga/cyclone-ps-spi.c: In function 'cyclonespi_write':
   include/linux/kernel.h:739:16: warning: comparison of distinct pointer types lacks a cast
     (void) (&min1 == &min2);   \
                   ^
   include/linux/kernel.h:742:2: note: in expansion of macro '__min'
     __min(typeof(x), typeof(y),   \
     ^~~~~
   drivers/fpga/cyclone-ps-spi.c:93:19: note: in expansion of macro 'min'
      size_t stride = min(fw_data_end - fw_data, SZ_4K);
                      ^~~

vim +93 drivers/fpga/cyclone-ps-spi.c

    77		/* set buffer to lsb first */
    78		while (fw32 < fw_end) {
    79			*fw32 = bitrev8x4(*fw32);
    80			fw32++;
    81		}
    82	}
    83	
    84	static int cyclonespi_write(struct fpga_manager *mgr, const char *buf,
    85				    size_t count)
    86	{
    87		struct cyclonespi_conf *conf = (struct cyclonespi_conf *)mgr->priv;
    88		const char *fw_data = buf;
    89		const char *fw_data_end = fw_data + count;
    90	
    91		while (fw_data < fw_data_end) {
    92			int ret;
  > 93			size_t stride = min(fw_data_end - fw_data, SZ_4K);
    94	
    95			rev_buf((void *)fw_data, stride);
    96			ret = spi_write(conf->spi, fw_data, stride);
    97			if (ret) {
    98				dev_err(&mgr->dev, "spi error in firmware write: %d\n",
    99					ret);
   100				return ret;
   101			}

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
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Re: [PATCH v3 0/3] Altera Cyclone Passive Serial SPI FPGA Manager

[atull]

On Wed, 30 Nov 2016, Joshua Clayton wrote:

Hi Joshua,

The DT bindings will need Rob Herring's ack.  The bitrev.h
changes will need Russell King's ack.

I've made some comments on patch 3/3 but it looks good to me
besides that.

Once we have those other acks, please submit your v4 including fixes
for my comments and whatever else comes up.  I'm hoping it will be
minor and with that done, v4 can go in.

When you send in v4, please also cc our new mailing list that Moritz
made: linux-fpga@vger.kernel.org

Alan

> This series adds an FPGA manager for Altera cyclone FPGAs
> that can program them using an spi port and a couple of gpios, using
> Alteras passive serial protocol.
> 
> Changes from v2:
> 
> - Merged patch 3 and 4 as suggested in review by Moritz Fischer
> - Changed FPGA_MIN_DELAY from 250 to 50 ms is the time advertized by
>   Altera. This now works, as we don't assume it is done
> 
> Changes from v1:
> - Changed the name from cyclone-spi-fpga-mgr to cyclone-ps-spi-fpga-mgr
>   This name change was requested by Alan Tull, to be specific about which
>   programming method is being employed on the fpga.
> - Changed the name of the reset-gpio to config-gpio to closer match the
>   way the pins are described in the Altera manual
> - Moved MODULE_LICENCE, _AUTHOR, and _DESCRIPTION to the bottom
> 
> - Added a bitrev8x4() function to the bitrev headers and implemented ARM
>  const, runtime, and ARM specific faster versions (This may end up
>  needing to be a standalone patch)
> 
> - Moved the bitswapping into cyclonespi_write(), as requested.
>   This falls short of my desired generic lsb first spi support, but is a step
>   in that direction.
> 
> - Fixed whitespace problems introduced during refactoring
> 
> - Replaced magic number for initial delay with a descriptive macro
> - Poll the fpga to see when it is ready rather than a fixed 1 ms sleep
> 
> Joshua Clayton (3):
>   lib: add bitrev8x4()
>   doc: dt: add cyclone-spi binding document
>   fpga manager: Add cyclone-ps-spi driver for Altera FPGAs
> 
>  .../bindings/fpga/cyclone-ps-spi-fpga-mgr.txt      |  23 +++
>  arch/arm/include/asm/bitrev.h                      |   5 +
>  drivers/fpga/Kconfig                               |   7 +
>  drivers/fpga/Makefile                              |   1 +
>  drivers/fpga/cyclone-ps-spi.c                      | 176 +++++++++++++++++++++
>  include/linux/bitrev.h                             |  26 +++
>  6 files changed, 238 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/fpga/cyclone-ps-spi-fpga-mgr.txt
>  create mode 100644 drivers/fpga/cyclone-ps-spi.c
> 
> -- 
> 2.9.3
> 
>