Messages in this thread | | | Subject | Re: [PATCH v4 5/6] spi: at91-usart: add driver for at91-usart as spi | From | Radu Pirea <> | Date | Tue, 29 May 2018 17:28:37 +0300 |
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On 05/28/2018 11:21 AM, Andy Shevchenko wrote: > 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?
I need of_gpio.h for of_gpio_named_count, of_get_named_gpio and devm_gpio_request_one(found in gpio.h)
> >> +#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'll fix it.
> > 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_
Good ideea. I will change the names.
> >> + /*used in interrupt to protect data reading*/ > > Comment style. > > You need to read some existing code, perhaps, to see how it's done.
Ok. I will add the comment.
> >> +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;
Thank for suggestion. I will change.
> >> + 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.
Ok. What do you suggest to use instead of OF API to get the count of cs-gpios and to read their values one by one?
> >> + 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.
I know weird, but is the safest way to pass the resource and the of_node.
> >> + 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. >
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