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From: Felix Fietkau <nbd@nbd.name>
Date: Fri, 9 Dec 2016 20:09:16 +0100
Subject: [PATCH] spi: spi-ath79: support multiple internal chip select
lines
Several devices with multiple flash chips use the internal chip select
lines. Don't assume that chip select 1 and above are GPIO lines.
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
--- a/drivers/spi/spi-ath79.c
+++ b/drivers/spi/spi-ath79.c
@@ -78,14 +78,16 @@ static void ath79_spi_chipselect(struct
ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, sp->ioc_base);
}
- if (spi->chip_select) {
+ if (gpio_is_valid(spi->cs_gpio)) {
/* SPI is normally active-low */
gpio_set_value(spi->cs_gpio, cs_high);
} else {
+ u32 cs_bit = AR71XX_SPI_IOC_CS(spi->chip_select);
+
if (cs_high)
- sp->ioc_base |= AR71XX_SPI_IOC_CS0;
+ sp->ioc_base |= cs_bit;
else
- sp->ioc_base &= ~AR71XX_SPI_IOC_CS0;
+ sp->ioc_base &= ~cs_bit;
ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, sp->ioc_base);
}
@@ -118,11 +120,8 @@ static int ath79_spi_setup_cs(struct spi
struct ath79_spi *sp = ath79_spidev_to_sp(spi);
int status;
- if (spi->chip_select && !gpio_is_valid(spi->cs_gpio))
- return -EINVAL;
-
status = 0;
- if (spi->chip_select) {
+ if (gpio_is_valid(spi->cs_gpio)) {
unsigned long flags;
flags = GPIOF_DIR_OUT;
@@ -134,10 +133,12 @@ static int ath79_spi_setup_cs(struct spi
status = gpio_request_one(spi->cs_gpio, flags,
dev_name(&spi->dev));
} else {
+ u32 cs_bit = AR71XX_SPI_IOC_CS(spi->chip_select);
+
if (spi->mode & SPI_CS_HIGH)
- sp->ioc_base &= ~AR71XX_SPI_IOC_CS0;
+ sp->ioc_base &= ~cs_bit;
else
- sp->ioc_base |= AR71XX_SPI_IOC_CS0;
+ sp->ioc_base |= cs_bit;
ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, sp->ioc_base);
}
@@ -147,7 +148,7 @@ static int ath79_spi_setup_cs(struct spi
static void ath79_spi_cleanup_cs(struct spi_device *spi)
{
- if (spi->chip_select) {
+ if (gpio_is_valid(spi->cs_gpio)) {
gpio_free(spi->cs_gpio);
}
}
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