Re: [PATCH v3 2/4] Firmware: provide a handler to program Altera FPGAs

[Sascha Hauer <s.hauer@pengutronix.de>]

On Thu, Sep 04, 2014 at 03:47:15PM +0200, Steffen Trumtrar wrote:
> +/*
> + * Physical requirements:
> + * - three free GPIOs for the signals nCONFIG, CONFIGURE_DONE, nSTATUS
> + * - 32 bit per word, LSB first capable SPI master (MOSI + clock)
> + *
> + * Example how to configure this driver via device tree
> + *
> + *	fpga@0 {
> + *		compatible = "altr,fpga-passive-serial";
> + *		nstat-gpio = <&gpio4 18 0>;
> + *		confd-gpio = <&gpio4 19 0>;
> + *		nconfig-gpio = <&gpio4 20 0>;
> + *		spi-max-frequency = <10000000>;
> + *		reg = <0>;
> + *	};

We have Documentation/devicetree/bindings/. Please add a document there.

> +
> +	/*
> +	 * after about 2 µs the FPGA must acknowledge with
> +	 * STATUS and CONFIG DONE lines at low level
> +	 */
> +	ret = wait_on_timeout(2 * 1000,
> +				(gpio_get_value(this->nstat_gpio) == 0) &&
> +				(gpio_get_value(this->confd_gpio) == 0));

2 * USECOND please, also for the other calls to wait_on_timeout().

> +static int altera_spi_write(struct firmware_handler *fh, const void *buf, size_t sz)
> +{
> +	struct fpga_spi *this = container_of(fh, struct fpga_spi, fh);
> +	struct device_d *dev = this->dev;
> +	struct spi_transfer t[2];
> +	struct spi_message m;
> +	u32 dummy;
> +	int ret;
> +
> +	printf("%s: %d\n", __func__, sz);

Is this useful output for production?

> +	/*
> +	 * when programming was successfully,

s/successfully/successful/

> +	 * both status lines should be at high level
> +	 */
> +	ret = wait_on_timeout(10 * 1000,
> +				(gpio_get_value(this->nstat_gpio) == 1) &&
> +				(gpio_get_value(this->confd_gpio) == 1));
> +	if (ret == 0) {
> +		dev_dbg(dev, "Programming successfull\n");

s/successfull/successful/

Sascha

-- 
Pengutronix e.K.                           |                             |
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