Messages in this thread | | | From | Andy Shevchenko <> | Date | Mon, 28 May 2018 11:21:26 +0300 | Subject | Re: [PATCH v4 5/6] spi: at91-usart: add driver for at91-usart as spi |
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On Fri, May 25, 2018 at 8:19 PM, Radu Pirea <radu.pirea@microchip.com> wrote: > This is the driver for at91-usart in spi mode. The USART IP can be configured > to work in many modes and one of them is SPI. > > The driver was tested on sama5d3-xplained and sama5d4-xplained boards with > enc28j60 ethernet controller as slave.
> +#include <linux/of_gpio.h>
What is the use of it?
> +#define US_INIT (US_MR_SPI_MASTER | US_MR_CHRL | US_MR_CLKO | \ > + US_MR_WRDBT)
Don't split lines like this, it's hard to read.
#define FOO \ (BAR1 | BAR2)
I think I already told this to someone recently, maybe to you.
> +/* Register access macros */ > +#define spi_readl(port, reg) \ > + readl_relaxed((port)->regs + US_##reg) > +#define spi_writel(port, reg, value) \ > + writel_relaxed((value), (port)->regs + US_##reg) > + > +#define spi_readb(port, reg) \ > + readb_relaxed((port)->regs + US_##reg) > +#define spi_writeb(port, reg, value) \ > + writeb_relaxed((value), (port)->regs + US_##reg)
Names are too generic. You better to use the same prefix as for the rest, i.e. at91_spi_
> + /*used in interrupt to protect data reading*/
Comment style.
You need to read some existing code, perhaps, to see how it's done.
> +static inline void at91_usart_spi_tx(struct at91_usart_spi *aus) > +{ > + unsigned int len = aus->current_transfer->len; > + unsigned int remaining = aus->current_tx_remaining_bytes; > + const u8 *tx_buf = aus->current_transfer->tx_buf; > +
> + if (remaining) > + if (at91_usart_spi_tx_ready(aus)) {
if (x) { if (y) { ... } }
is equivalent to if (x && y) {}.
Though, considering your intention here, I would rather go with better pattern, i.e.
if (!remaining) return;
> + spi_writeb(aus, THR, tx_buf[len - remaining]); > + aus->current_tx_remaining_bytes--; > + } > +} > + > +static inline void at91_usart_spi_rx(struct at91_usart_spi *aus) > +{
> + if (remaining) { > + rx_buf[len - remaining] = spi_readb(aus, RHR); > + aus->current_rx_remaining_bytes--; > + }
Ditto.
> +}
> +static int at91_usart_gpio_setup(struct platform_device *pdev) > +{
> + struct device_node *np = pdev->dev.parent->of_node;
Your driver is not OF specific as far as I can see. Drop all these device_node stuff and change API calls respectively.
> + int i;
> + int ret = 0; > + int nb = 0;
What happened to indentation?
Redundnant assignment for both.
> + if (!np) > + return -EINVAL; > + > + nb = of_gpio_named_count(np, "cs-gpios"); > + for (i = 0; i < nb; i++) { > + int cs_gpio = of_get_named_gpio(np, "cs-gpios", i); > + > + if (cs_gpio < 0) > + return cs_gpio; > + > + if (gpio_is_valid(cs_gpio)) { > + ret = devm_gpio_request_one(&pdev->dev, cs_gpio, > + GPIOF_DIR_OUT, > + dev_name(&pdev->dev)); > + if (ret) > + return ret; > + } > + } > + > + return 0; > +} > + > +static int at91_usart_spi_probe(struct platform_device *pdev) > +{
> + regs = platform_get_resource(to_platform_device(pdev->dev.parent), > + IORESOURCE_MEM, 0); > + if (!regs) > + return -EINVAL;
This looks weird. Supply resource to _this_ device in your MFD code.
> + dev_info(&pdev->dev, > + "Atmel USART SPI Controller version 0x%x at 0x%08lx (irq %d)\n", > + spi_readl(aus, VERSION), > + (unsigned long)regs->start, irq);
I think I already told you, don't use explicit casting when print. If it wasn't you, do you homework then. But above is no go.
> + return 0;
> +static struct platform_driver at91_usart_spi_driver = { > + .driver = { > + .name = "at91_usart_spi",
> + .of_match_table = of_match_ptr(at91_usart_spi_dt_ids),
Drop of_match_ptr(). It's not needed.
> + }, > + .probe = at91_usart_spi_probe,
> + .remove = at91_usart_spi_remove, };
Already told ya, split lines correctly.
-- With Best Regards, Andy Shevchenko
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