On 05/28/2018 11:21 AM, Andy Shevchenko wrote:
On Fri, May 25, 2018 at 8:19 PM, Radu Pirea <radu.pirea@xxxxxxxxxxxxx> 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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