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spi: atmel_spi: Use VERSION register instead of CPU type 

Use VERSION register instead of CPU type to determine IP block's version
and capabilities. This what corresponding Linux kernel driver does.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This commit is contained in:
Andrey Smirnov 2017-03-08 14:09:08 -08:00 committed by Sascha Hauer
parent dd0f42879b
commit d6200fe415
2 changed files with 30 additions and 6 deletions
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35
drivers/spi/atmel_spi.c
View File

@ -40,11 +40,16 @@
#include "atmel_spi.h"
struct atmel_spi_caps {
bool is_spi2;
};
struct atmel_spi {
struct spi_master master;
void __iomem *regs;
struct clk *clk;
int *cs_pins;
struct atmel_spi_caps caps;
};
#define to_atmel_spi(p) container_of(p, struct atmel_spi, master)
@ -62,9 +67,9 @@ struct atmel_spi {
* register, but I haven't checked that it exists on all chips, and
* this is cheaper anyway.
*/
static inline bool atmel_spi_is_v2(void)
static inline bool atmel_spi_is_v2(struct atmel_spi *as)
{
return !cpu_is_at91rm9200();
return as->caps.is_spi2;
}
/*
@ -104,7 +109,7 @@ static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
csr = (u32)spi->controller_data;
if (atmel_spi_is_v2()) {
if (atmel_spi_is_v2(as)) {
/*
* Always use CSR0. This ensures that the clock
* switches to the correct idle polarity before we
@ -163,8 +168,9 @@ static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi)
npcs_pin, active ? " (low)" : "",
mr);
if (atmel_spi_is_v2() || npcs_pin != AT91_PIN_PA3)
if (atmel_spi_is_v2(as) || npcs_pin != AT91_PIN_PA3) {
gpio_set_value(npcs_pin, !active);
}
}
static int atmel_spi_setup(struct spi_device *spi)
@ -199,7 +205,7 @@ static int atmel_spi_setup(struct spi_device *spi)
spi->max_speed_hz);
bus_hz = clk_get_rate(as->clk);
if (!atmel_spi_is_v2())
if (!atmel_spi_is_v2(as))
bus_hz /= 2;
if (spi->max_speed_hz) {
@ -248,7 +254,7 @@ static int atmel_spi_setup(struct spi_device *spi)
cs_deactivate(as, spi);
if (!atmel_spi_is_v2())
if (!atmel_spi_is_v2(as))
spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
return 0;
@ -373,6 +379,21 @@ err:
return ret;
}
static inline unsigned int atmel_get_version(struct atmel_spi *as)
{
return spi_readl(as, VERSION) & 0x00000fff;
}
static void atmel_get_caps(struct atmel_spi *as)
{
unsigned int version;
version = atmel_get_version(as);
dev_info(as->master.dev, "version: 0x%x\n", version);
as->caps.is_spi2 = version > 0x121;
}
static int atmel_spi_probe(struct device_d *dev)
{
struct resource *iores;
@ -409,6 +430,8 @@ static int atmel_spi_probe(struct device_d *dev)
return PTR_ERR(iores);
as->regs = IOMEM(iores->start);
atmel_get_caps(as);
for (i = 0; i < master->num_chipselect; i++) {
ret = gpio_request(as->cs_pins[i], dev_name(dev));
if (ret)

1
drivers/spi/atmel_spi.h
View File

@ -23,6 +23,7 @@
#define SPI_CSR1 0x0034
#define SPI_CSR2 0x0038
#define SPI_CSR3 0x003c
#define SPI_VERSION 0x00fc
#define SPI_RPR 0x0100
#define SPI_RCR 0x0104
#define SPI_TPR 0x0108