Message ID | 20200622133723.23326-1-luca@lucaceresoli.net |
---|---|
State | Not Applicable, archived |
Headers | show |
Series | [v2,1/2] dt-bindings: fpga: xilinx-slave-serial: add optional INIT_B GPIO | expand |
Context | Check | Description |
---|---|---|
robh/checkpatch | success |
On Mon, Jun 22, 2020 at 03:37:22PM +0200, Luca Ceresoli wrote: > The INIT_B is used by the 6 and 7 series to report the programming status, > providing more control and information about programming errors. > > Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net> > > --- > > Changes in v2: > - rename init_b-gpios to init-b-gpios (Rob Herring suggested to not use '_' > in property names) > --- > .../devicetree/bindings/fpga/xilinx-slave-serial.txt | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/Documentation/devicetree/bindings/fpga/xilinx-slave-serial.txt b/Documentation/devicetree/bindings/fpga/xilinx-slave-serial.txt > index 9f103f3872e8..5ef659c1394d 100644 > --- a/Documentation/devicetree/bindings/fpga/xilinx-slave-serial.txt > +++ b/Documentation/devicetree/bindings/fpga/xilinx-slave-serial.txt > @@ -16,6 +16,10 @@ Required properties: > - prog_b-gpios: config pin (referred to as PROGRAM_B in the manual) > - done-gpios: config status pin (referred to as DONE in the manual) > > +Optional properties: > +- init-b-gpios: initialization status and configuration error pin > + (referred to as INIT_B in the manual) > + > Example for full FPGA configuration: > > fpga-region0 { > @@ -40,7 +44,8 @@ Example for full FPGA configuration: > spi-max-frequency = <60000000>; > spi-cpha; > reg = <0>; > - done-gpios = <&gpio0 9 GPIO_ACTIVE_HIGH>; > prog_b-gpios = <&gpio0 29 GPIO_ACTIVE_LOW>; > + init-b-gpios = <&gpio0 28 GPIO_ACTIVE_LOW>; > + done-gpios = <&gpio0 9 GPIO_ACTIVE_HIGH>; > }; > }; > -- > 2.27.0 > Will apply to for-next, Thanks!
On Mon, Jun 22, 2020 at 03:37:23PM +0200, Luca Ceresoli wrote: > The INIT_B pin reports the status during startup and after the end of the > programming process. However the current driver completely ignores it. > > Check the pin status during startup to make sure programming is never > started too early and also to detect any hardware issues in the FPGA > connection. > > This is optional for backward compatibility. If INIT_B is not passed by > device tree, just fallback to the old udelays. > > Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net> > > --- > > Changes in v2: > - rename DT property init_b-gpios to init-b-gpios (Rob Herring suggested to > not use '_' in property names) > - improve wait_for_init_b() documentation and variable naming > --- > drivers/fpga/xilinx-spi.c | 55 ++++++++++++++++++++++++++++++++++++++- > 1 file changed, 54 insertions(+), 1 deletion(-) > > diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c > index 799ae04301be..2967aa2a74e2 100644 > --- a/drivers/fpga/xilinx-spi.c > +++ b/drivers/fpga/xilinx-spi.c > @@ -23,6 +23,7 @@ > struct xilinx_spi_conf { > struct spi_device *spi; > struct gpio_desc *prog_b; > + struct gpio_desc *init_b; > struct gpio_desc *done; > }; > > @@ -36,11 +37,45 @@ static enum fpga_mgr_states xilinx_spi_state(struct fpga_manager *mgr) > return FPGA_MGR_STATE_UNKNOWN; > } > > +/** > + * wait_for_init_b - wait for the INIT_B pin to have a given state, or wait > + * a given delay if the pin is unavailable > + * > + * @mgr: The FPGA manager object > + * @value: Value INIT_B to wait for (1 = asserted = low) > + * @alt_udelay: Delay to wait if the INIT_B GPIO is not available > + * > + * Returns 0 when the INIT_B GPIO reached the given state or -ETIMEDOUT if > + * too much time passed waiting for that. If no INIT_B GPIO is available > + * then always return 0. > + */ > +static int wait_for_init_b(struct fpga_manager *mgr, int value, > + unsigned long alt_udelay) > +{ > + struct xilinx_spi_conf *conf = mgr->priv; > + unsigned long timeout = jiffies + msecs_to_jiffies(1000); > + > + if (conf->init_b) { > + while (time_before(jiffies, timeout)) { > + /* dump_state(conf, "wait for init_d .."); */ > + if (gpiod_get_value(conf->init_b) == value) > + return 0; > + usleep_range(100, 400); > + } > + return -ETIMEDOUT; > + } > + > + udelay(alt_udelay); > + > + return 0; > +} > + > static int xilinx_spi_write_init(struct fpga_manager *mgr, > struct fpga_image_info *info, > const char *buf, size_t count) > { > struct xilinx_spi_conf *conf = mgr->priv; > + int err; > > if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) { > dev_err(&mgr->dev, "Partial reconfiguration not supported.\n"); > @@ -49,10 +84,21 @@ static int xilinx_spi_write_init(struct fpga_manager *mgr, > > gpiod_set_value(conf->prog_b, 1); > > - udelay(1); /* min is 500 ns */ > + err = wait_for_init_b(mgr, 1, 1); /* min is 500 ns */ > + if (err) { > + dev_err(&mgr->dev, "INIT_B pin did not go low\n"); > + gpiod_set_value(conf->prog_b, 0); > + return err; > + } > > gpiod_set_value(conf->prog_b, 0); > > + err = wait_for_init_b(mgr, 0, 0); > + if (err) { > + dev_err(&mgr->dev, "INIT_B pin did not go high\n"); > + return err; > + } > + > if (gpiod_get_value(conf->done)) { > dev_err(&mgr->dev, "Unexpected DONE pin state...\n"); > return -EIO; > @@ -154,6 +200,13 @@ static int xilinx_spi_probe(struct spi_device *spi) > return PTR_ERR(conf->prog_b); > } > > + conf->init_b = devm_gpiod_get_optional(&spi->dev, "init-b", GPIOD_IN); > + if (IS_ERR(conf->init_b)) { > + dev_err(&spi->dev, "Failed to get INIT_B gpio: %ld\n", > + PTR_ERR(conf->init_b)); > + return PTR_ERR(conf->init_b); > + } > + > conf->done = devm_gpiod_get(&spi->dev, "done", GPIOD_IN); > if (IS_ERR(conf->done)) { > dev_err(&spi->dev, "Failed to get DONE gpio: %ld\n", > -- > 2.27.0 > Will apply to for-next, Thanks!
diff --git a/Documentation/devicetree/bindings/fpga/xilinx-slave-serial.txt b/Documentation/devicetree/bindings/fpga/xilinx-slave-serial.txt index 9f103f3872e8..5ef659c1394d 100644 --- a/Documentation/devicetree/bindings/fpga/xilinx-slave-serial.txt +++ b/Documentation/devicetree/bindings/fpga/xilinx-slave-serial.txt @@ -16,6 +16,10 @@ Required properties: - prog_b-gpios: config pin (referred to as PROGRAM_B in the manual) - done-gpios: config status pin (referred to as DONE in the manual) +Optional properties: +- init-b-gpios: initialization status and configuration error pin + (referred to as INIT_B in the manual) + Example for full FPGA configuration: fpga-region0 { @@ -40,7 +44,8 @@ Example for full FPGA configuration: spi-max-frequency = <60000000>; spi-cpha; reg = <0>; - done-gpios = <&gpio0 9 GPIO_ACTIVE_HIGH>; prog_b-gpios = <&gpio0 29 GPIO_ACTIVE_LOW>; + init-b-gpios = <&gpio0 28 GPIO_ACTIVE_LOW>; + done-gpios = <&gpio0 9 GPIO_ACTIVE_HIGH>; }; };
The INIT_B is used by the 6 and 7 series to report the programming status, providing more control and information about programming errors. Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net> --- Changes in v2: - rename init_b-gpios to init-b-gpios (Rob Herring suggested to not use '_' in property names) --- .../devicetree/bindings/fpga/xilinx-slave-serial.txt | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)