[PATCH 1/8] spi: sirf: correct spi gpio and hardware chipselect behaviour
Barry Song
Barry.Song at csr.com
Tue Sep 2 02:01:01 PDT 2014
From: Qipan Li <Qipan.Li at csr.com>
the old codes check the cs-gpios, if the gpio number is 0 like:
<&gpio, 0, 0>, the driver will use the only hardware chipselect.
this is wrong because of_spi_register_master() can read property
cs-gpios from device node and set the spi master's cs number and
gpio cs automatically based on whether the cs-gpios is valid.
this patch fixes the beviour of CSR spi driver and move to a core
level supported way.
Signed-off-by: Qipan Li <Qipan.Li at csr.com>
Signed-off-by: Barry Song <Baohua.Song at csr.com>
---
drivers/spi/spi-sirf.c | 86 +++++++++++++++++++-------------------------------
1 file changed, 33 insertions(+), 53 deletions(-)
diff --git a/drivers/spi/spi-sirf.c b/drivers/spi/spi-sirf.c
index 95ac276..44ec3bb 100644
--- a/drivers/spi/spi-sirf.c
+++ b/drivers/spi/spi-sirf.c
@@ -170,8 +170,7 @@ struct sirfsoc_spi {
* command model
*/
bool tx_by_cmd;
-
- int chipselect[0];
+ bool hw_cs;
};
static void spi_sirfsoc_rx_word_u8(struct sirfsoc_spi *sspi)
@@ -484,7 +483,7 @@ static void spi_sirfsoc_chipselect(struct spi_device *spi, int value)
{
struct sirfsoc_spi *sspi = spi_master_get_devdata(spi->master);
- if (sspi->chipselect[spi->chip_select] == 0) {
+ if (sspi->hw_cs) {
u32 regval = readl(sspi->base + SIRFSOC_SPI_CTRL);
switch (value) {
case BITBANG_CS_ACTIVE:
@@ -502,14 +501,13 @@ static void spi_sirfsoc_chipselect(struct spi_device *spi, int value)
}
writel(regval, sspi->base + SIRFSOC_SPI_CTRL);
} else {
- int gpio = sspi->chipselect[spi->chip_select];
switch (value) {
case BITBANG_CS_ACTIVE:
- gpio_direction_output(gpio,
+ gpio_direction_output(spi->cs_gpio,
spi->mode & SPI_CS_HIGH ? 1 : 0);
break;
case BITBANG_CS_INACTIVE:
- gpio_direction_output(gpio,
+ gpio_direction_output(spi->cs_gpio,
spi->mode & SPI_CS_HIGH ? 0 : 1);
break;
}
@@ -603,8 +601,8 @@ spi_sirfsoc_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
sspi->tx_by_cmd = false;
}
/*
- * set spi controller in RISC chipselect mode, we are controlling CS by
- * software BITBANG_CS_ACTIVE and BITBANG_CS_INACTIVE.
+ * it should never set to hardware cs mode because in hardware cs mode,
+ * cs signal can't controlled by driver.
*/
regval |= SIRFSOC_SPI_CS_IO_MODE;
writel(regval, sspi->base + SIRFSOC_SPI_CTRL);
@@ -627,9 +625,17 @@ spi_sirfsoc_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
static int spi_sirfsoc_setup(struct spi_device *spi)
{
+ struct sirfsoc_spi *sspi;
+
if (!spi->max_speed_hz)
return -EINVAL;
+ sspi = spi_master_get_devdata(spi->master);
+
+ if (spi->cs_gpio == -ENOENT)
+ sspi->hw_cs = true;
+ else
+ sspi->hw_cs = false;
return spi_sirfsoc_setup_transfer(spi, NULL);
}
@@ -638,19 +644,10 @@ static int spi_sirfsoc_probe(struct platform_device *pdev)
struct sirfsoc_spi *sspi;
struct spi_master *master;
struct resource *mem_res;
- int num_cs, cs_gpio, irq;
- int i;
- int ret;
-
- ret = of_property_read_u32(pdev->dev.of_node,
- "sirf,spi-num-chipselects", &num_cs);
- if (ret < 0) {
- dev_err(&pdev->dev, "Unable to get chip select number\n");
- goto err_cs;
- }
+ int irq;
+ int i, ret;
- master = spi_alloc_master(&pdev->dev,
- sizeof(*sspi) + sizeof(int) * num_cs);
+ master = spi_alloc_master(&pdev->dev, sizeof(*sspi));
if (!master) {
dev_err(&pdev->dev, "Unable to allocate SPI master\n");
return -ENOMEM;
@@ -658,32 +655,6 @@ static int spi_sirfsoc_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, master);
sspi = spi_master_get_devdata(master);
- master->num_chipselect = num_cs;
-
- for (i = 0; i < master->num_chipselect; i++) {
- cs_gpio = of_get_named_gpio(pdev->dev.of_node, "cs-gpios", i);
- if (cs_gpio < 0) {
- dev_err(&pdev->dev, "can't get cs gpio from DT\n");
- ret = -ENODEV;
- goto free_master;
- }
-
- sspi->chipselect[i] = cs_gpio;
- if (cs_gpio == 0)
- continue; /* use cs from spi controller */
-
- ret = gpio_request(cs_gpio, DRIVER_NAME);
- if (ret) {
- while (i > 0) {
- i--;
- if (sspi->chipselect[i] > 0)
- gpio_free(sspi->chipselect[i]);
- }
- dev_err(&pdev->dev, "fail to request cs gpios\n");
- goto free_master;
- }
- }
-
mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
sspi->base = devm_ioremap_resource(&pdev->dev, mem_res);
if (IS_ERR(sspi->base)) {
@@ -753,7 +724,21 @@ static int spi_sirfsoc_probe(struct platform_device *pdev)
ret = spi_bitbang_start(&sspi->bitbang);
if (ret)
goto free_dummypage;
-
+ for (i = 0; master->cs_gpios && i < master->num_chipselect; i++) {
+ if (master->cs_gpios[i] == -ENOENT)
+ continue;
+ if (!gpio_is_valid(master->cs_gpios[i])) {
+ dev_err(&pdev->dev, "no valid gpio\n");
+ ret = -EINVAL;
+ goto free_dummypage;
+ }
+ ret = devm_gpio_request(&pdev->dev,
+ master->cs_gpios[i], DRIVER_NAME);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to request gpio\n");
+ goto free_dummypage;
+ }
+ }
dev_info(&pdev->dev, "registerred, bus number = %d\n", master->bus_num);
return 0;
@@ -768,7 +753,7 @@ free_rx_dma:
dma_release_channel(sspi->rx_chan);
free_master:
spi_master_put(master);
-err_cs:
+
return ret;
}
@@ -776,16 +761,11 @@ static int spi_sirfsoc_remove(struct platform_device *pdev)
{
struct spi_master *master;
struct sirfsoc_spi *sspi;
- int i;
master = platform_get_drvdata(pdev);
sspi = spi_master_get_devdata(master);
spi_bitbang_stop(&sspi->bitbang);
- for (i = 0; i < master->num_chipselect; i++) {
- if (sspi->chipselect[i] > 0)
- gpio_free(sspi->chipselect[i]);
- }
kfree(sspi->dummypage);
clk_disable_unprepare(sspi->clk);
clk_put(sspi->clk);
--
2.1.0
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