diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 8feac599e9ab4bfe886b8da89960f04ed32c1aba..9fb00ac3ac2ef023820df542bb4c1d70376dd547 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -24,6 +24,7 @@
#include <linux/io.h>
#include <linux/gpio.h>
+#include <linux/of_gpio.h>
#include <linux/pinctrl/consumer.h>
#include <linux/pm_runtime.h>
@@ -295,6 +296,7 @@ struct atmel_spi {
int irq;
struct clk *clk;
struct platform_device *pdev;
+ unsigned long spi_clk;
struct spi_transfer *current_transfer;
int current_remaining_bytes;
@@ -864,7 +866,7 @@ static int atmel_spi_set_xfer_speed(struct atmel_spi *as,
unsigned long bus_hz;
/* v1 chips start out at half the peripheral bus speed. */
- bus_hz = clk_get_rate(as->clk);
+ bus_hz = as->spi_clk;
if (!atmel_spi_is_v2(as))
bus_hz /= 2;
@@ -1204,7 +1206,6 @@ static int atmel_spi_setup(struct spi_device *spi)
u32 csr;
unsigned int bits = spi->bits_per_word;
unsigned int npcs_pin;
- int ret;
as = spi_master_get_devdata(spi->master);
@@ -1247,16 +1248,9 @@ static int atmel_spi_setup(struct spi_device *spi)
if (!asd)
return -ENOMEM;
- if (as->use_cs_gpios) {
- ret = gpio_request(npcs_pin, dev_name(&spi->dev));
- if (ret) {
- kfree(asd);
- return ret;
- }
-
+ if (as->use_cs_gpios)
gpio_direction_output(npcs_pin,
!(spi->mode & SPI_CS_HIGH));
- }
asd->npcs_pin = npcs_pin;
spi->controller_state = asd;
@@ -1471,13 +1465,11 @@ static int atmel_spi_transfer_one_message(struct spi_master *master,
static void atmel_spi_cleanup(struct spi_device *spi)
{
struct atmel_spi_device *asd = spi->controller_state;
- unsigned gpio = (unsigned long) spi->controller_data;
if (!asd)
return;
spi->controller_state = NULL;
- gpio_free(gpio);
kfree(asd);
}
@@ -1499,6 +1491,39 @@ static void atmel_get_caps(struct atmel_spi *as)
}
/*-------------------------------------------------------------------------*/
+static int atmel_spi_gpio_cs(struct platform_device *pdev)
+{
+ struct spi_master *master = platform_get_drvdata(pdev);
+ struct atmel_spi *as = spi_master_get_devdata(master);
+ struct device_node *np = master->dev.of_node;
+ int i;
+ int ret = 0;
+ int nb = 0;
+
+ if (!as->use_cs_gpios)
+ return 0;
+
+ if (!np)
+ return 0;
+
+ nb = of_gpio_named_count(np, "cs-gpios");
+ for (i = 0; i < nb; i++) {
+ int cs_gpio = of_get_named_gpio(pdev->dev.of_node,
+ "cs-gpios", i);
+
+ if (cs_gpio == -EPROBE_DEFER)
+ return cs_gpio;
+
+ if (gpio_is_valid(cs_gpio)) {
+ ret = devm_gpio_request(&pdev->dev, cs_gpio,
+ dev_name(&pdev->dev));
+ if (ret)
+ return ret;
+ }
+ }
+
+ return 0;
+}
static int atmel_spi_probe(struct platform_device *pdev)
{
@@ -1577,6 +1602,10 @@ static int atmel_spi_probe(struct platform_device *pdev)
master->num_chipselect = 4;
}
+ ret = atmel_spi_gpio_cs(pdev);
+ if (ret)
+ goto out_unmap_regs;
+
as->use_dma = false;
as->use_pdc = false;
if (as->caps.has_dma_support) {
@@ -1606,6 +1635,9 @@ static int atmel_spi_probe(struct platform_device *pdev)
ret = clk_prepare_enable(clk);
if (ret)
goto out_free_irq;
+
+ as->spi_clk = clk_get_rate(clk);
+
spi_writel(as, CR, SPI_BIT(SWRST));
spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
if (as->caps.has_wdrbt) {
diff --git a/drivers/spi/spi-orion.c b/drivers/spi/spi-orion.c
index ded37025b445834d0367ef41cac7aa80b2c656cf..6b001c4a564086528e9db608f7250305656d5da7 100644
--- a/drivers/spi/spi-orion.c
+++ b/drivers/spi/spi-orion.c
@@ -138,37 +138,62 @@ static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
tclk_hz = clk_get_rate(orion_spi->clk);
if (devdata->typ == ARMADA_SPI) {
- unsigned int clk, spr, sppr, sppr2, err;
- unsigned int best_spr, best_sppr, best_err;
-
- best_err = speed;
- best_spr = 0;
- best_sppr = 0;
-
- /* Iterate over the valid range looking for best fit */
- for (sppr = 0; sppr < 8; sppr++) {
- sppr2 = 0x1 << sppr;
-
- spr = tclk_hz / sppr2;
- spr = DIV_ROUND_UP(spr, speed);
- if ((spr == 0) || (spr > 15))
- continue;
-
- clk = tclk_hz / (spr * sppr2);
- err = speed - clk;
-
- if (err < best_err) {
- best_spr = spr;
- best_sppr = sppr;
- best_err = err;
- }
- }
+ /*
+ * Given the core_clk (tclk_hz) and the target rate (speed) we
+ * determine the best values for SPR (in [0 .. 15]) and SPPR (in
+ * [0..7]) such that
+ *
+ * core_clk / (SPR * 2 ** SPPR)
+ *
+ * is as big as possible but not bigger than speed.
+ */
- if ((best_sppr == 0) && (best_spr == 0))
- return -EINVAL;
+ /* best integer divider: */
+ unsigned divider = DIV_ROUND_UP(tclk_hz, speed);
+ unsigned spr, sppr;
+
+ if (divider < 16) {
+ /* This is the easy case, divider is less than 16 */
+ spr = divider;
+ sppr = 0;
+
+ } else {
+ unsigned two_pow_sppr;
+ /*
+ * Find the highest bit set in divider. This and the
+ * three next bits define SPR (apart from rounding).
+ * SPPR is then the number of zero bits that must be
+ * appended:
+ */
+ sppr = fls(divider) - 4;
+
+ /*
+ * As SPR only has 4 bits, we have to round divider up
+ * to the next multiple of 2 ** sppr.
+ */
+ two_pow_sppr = 1 << sppr;
+ divider = (divider + two_pow_sppr - 1) & -two_pow_sppr;
+
+ /*
+ * recalculate sppr as rounding up divider might have
+ * increased it enough to change the position of the
+ * highest set bit. In this case the bit that now
+ * doesn't make it into SPR is 0, so there is no need to
+ * round again.
+ */
+ sppr = fls(divider) - 4;
+ spr = divider >> sppr;
+
+ /*
+ * Now do range checking. SPR is constructed to have a
+ * width of 4 bits, so this is fine for sure. So we
+ * still need to check for sppr to fit into 3 bits:
+ */
+ if (sppr > 7)
+ return -EINVAL;
+ }
- prescale = ((best_sppr & 0x6) << 5) |
- ((best_sppr & 0x1) << 4) | best_spr;
+ prescale = ((sppr & 0x6) << 5) | ((sppr & 0x1) << 4) | spr;
} else {
/*
* the supported rates are: 4,6,8...30
diff --git a/tools/spi/spidev_test.c b/tools/spi/spidev_test.c
index f046b77cfefe3056a72b82aa2194eb55e8b2fa93..816f119c9b7b1584a587077a55e28691418ff706 100644
--- a/tools/spi/spidev_test.c
+++ b/tools/spi/spidev_test.c
@@ -315,7 +315,7 @@ static void transfer_file(int fd, char *filename)
pabort("can't stat input file");
tx_fd = open(filename, O_RDONLY);
- if (fd < 0)
+ if (tx_fd < 0)
pabort("can't open input file");
tx = malloc(sb.st_size);