[PATCH 1/2] spi: imx: add error checking
Uwe Kleine-König
u.kleine-koenig at pengutronix.de
Wed Aug 2 12:39:06 PDT 2017
This makes it possible that the xchg_single callbacks return an error code that
is then passed to the caller of spi_transfer. There is no change in behaviour
intended as up to now the callbacks always return 0.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
---
drivers/spi/imx_spi.c | 77 ++++++++++++++++++++++++++++++++-------------------
1 file changed, 48 insertions(+), 29 deletions(-)
diff --git a/drivers/spi/imx_spi.c b/drivers/spi/imx_spi.c
index 876699a02da1..97a2091969dd 100644
--- a/drivers/spi/imx_spi.c
+++ b/drivers/spi/imx_spi.c
@@ -38,8 +38,8 @@ struct imx_spi {
void __iomem *regs;
struct clk *clk;
- unsigned int (*xchg_single)(struct imx_spi *imx, u32 data);
- void (*do_transfer)(struct spi_device *spi);
+ int (*xchg_single)(struct imx_spi *imx, u32 txdata, u32 *rxdata);
+ int (*do_transfer)(struct spi_device *spi);
void (*chipselect)(struct spi_device *spi, int active);
const void *tx_buf;
@@ -49,8 +49,8 @@ struct imx_spi {
};
struct spi_imx_devtype_data {
- unsigned int (*xchg_single)(struct imx_spi *imx, u32 data);
- void (*do_transfer)(struct spi_device *spi);
+ int (*xchg_single)(struct imx_spi *imx, u32 txdata, u32 *rxdata);
+ int (*do_transfer)(struct spi_device *spi);
void (*chipselect)(struct spi_device *spi, int active);
void (*init)(struct imx_spi *imx);
};
@@ -86,13 +86,13 @@ static unsigned int imx_spi_maybe_reverse_bits(struct spi_device *spi, unsigned
return result;
}
-static unsigned int cspi_0_0_xchg_single(struct imx_spi *imx, unsigned int data)
+static int cspi_0_0_xchg_single(struct imx_spi *imx, u32 txdata, u32 *rxdata)
{
void __iomem *base = imx->regs;
unsigned int cfg_reg = readl(base + CSPI_0_0_CTRL);
- writel(data, base + CSPI_0_0_TXDATA);
+ writel(txdata, base + CSPI_0_0_TXDATA);
cfg_reg |= CSPI_0_0_CTRL_XCH;
@@ -100,7 +100,9 @@ static unsigned int cspi_0_0_xchg_single(struct imx_spi *imx, unsigned int data)
while (!(readl(base + CSPI_0_0_INT) & CSPI_0_0_STAT_RR));
- return readl(base + CSPI_0_0_RXDATA);
+ *rxdata = readl(base + CSPI_0_0_RXDATA);
+
+ return 0;
}
static void cspi_0_0_chipselect(struct spi_device *spi, int is_active)
@@ -152,13 +154,13 @@ static void cspi_0_0_init(struct imx_spi *imx)
} while (readl(base + CSPI_0_0_RESET) & CSPI_0_0_RESET_START);
}
-static unsigned int cspi_0_7_xchg_single(struct imx_spi *imx, unsigned int data)
+static int cspi_0_7_xchg_single(struct imx_spi *imx, u32 txdata, u32 *rxdata)
{
void __iomem *base = imx->regs;
unsigned int cfg_reg = readl(base + CSPI_0_7_CTRL);
- writel(data, base + CSPI_0_7_TXDATA);
+ writel(txdata, base + CSPI_0_7_TXDATA);
cfg_reg |= CSPI_0_7_CTRL_XCH;
@@ -167,7 +169,8 @@ static unsigned int cspi_0_7_xchg_single(struct imx_spi *imx, unsigned int data)
while (!(readl(base + CSPI_0_7_STAT) & CSPI_0_7_STAT_RR))
;
- return readl(base + CSPI_0_7_RXDATA);
+ *rxdata = readl(base + CSPI_0_7_RXDATA);
+ return 0;
}
/* MX1, MX31, MX35, MX51 CSPI */
@@ -242,15 +245,17 @@ static void cspi_0_7_init(struct imx_spi *imx)
readl(base + CSPI_0_7_RXDATA);
}
-static unsigned int cspi_2_3_xchg_single(struct imx_spi *imx, unsigned int data)
+static int cspi_2_3_xchg_single(struct imx_spi *imx, u32 txdata, u32 *rxdata)
{
void __iomem *base = imx->regs;
- writel(data, base + CSPI_2_3_TXDATA);
+ writel(txdata, base + CSPI_2_3_TXDATA);
while (!(readl(base + CSPI_2_3_STAT) & CSPI_2_3_STAT_RR));
- return readl(base + CSPI_2_3_RXDATA);
+ *rxdata = readl(base + CSPI_2_3_RXDATA);
+
+ return 0;
}
static unsigned int cspi_2_3_clkdiv(unsigned int fin, unsigned int fspi)
@@ -336,16 +341,20 @@ static void cspi_2_3_chipselect(struct spi_device *spi, int is_active)
gpio_set_value(gpio, gpio_cs);
}
-static u32 imx_xchg_single(struct spi_device *spi, u32 tx_val)
+static int imx_xchg_single(struct spi_device *spi, u32 tx_val, u32* rx_val)
{
- u32 rx_val;
struct imx_spi *imx = container_of(spi->master, struct imx_spi, master);
-
+ u32 local_rx_val;
+ int ret;
tx_val = imx_spi_maybe_reverse_bits(spi, tx_val);
- rx_val = imx->xchg_single(imx, tx_val);
+ ret = imx->xchg_single(imx, tx_val, &local_rx_val);
+ if (ret)
+ return ret;
- return imx_spi_maybe_reverse_bits(spi, rx_val);
+ *rx_val = imx_spi_maybe_reverse_bits(spi, local_rx_val);
+
+ return 0;
}
static void cspi_2_3_init(struct imx_spi *imx)
@@ -355,18 +364,21 @@ static void cspi_2_3_init(struct imx_spi *imx)
writel(0, base + CSPI_2_3_CTRL);
}
-static void imx_spi_do_transfer(struct spi_device *spi)
+static int imx_spi_do_transfer(struct spi_device *spi)
{
struct imx_spi *imx = container_of(spi->master, struct imx_spi, master);
unsigned i;
+ u32 rx_val;
+ int ret;
if (imx->bits_per_word <= 8) {
const u8 *tx_buf = imx->tx_buf;
u8 *rx_buf = imx->rx_buf;
- u8 rx_val;
for (i = 0; i < imx->xfer_len; i++) {
- rx_val = imx_xchg_single(spi, tx_buf ? tx_buf[i] : 0);
+ ret = imx_xchg_single(spi, tx_buf ? tx_buf[i] : 0, &rx_val);
+ if (ret)
+ return ret;
if (rx_buf)
rx_buf[i] = rx_val;
@@ -374,10 +386,11 @@ static void imx_spi_do_transfer(struct spi_device *spi)
} else if (imx->bits_per_word <= 16) {
const u16 *tx_buf = imx->tx_buf;
u16 *rx_buf = imx->rx_buf;
- u16 rx_val;
for (i = 0; i < imx->xfer_len >> 1; i++) {
- rx_val = imx_xchg_single(spi, tx_buf ? tx_buf[i] : 0);
+ ret = imx_xchg_single(spi, tx_buf ? tx_buf[i] : 0, &rx_val);
+ if (ret)
+ return ret;
if (rx_buf)
rx_buf[i] = rx_val;
@@ -385,15 +398,18 @@ static void imx_spi_do_transfer(struct spi_device *spi)
} else if (imx->bits_per_word <= 32) {
const u32 *tx_buf = imx->tx_buf;
u32 *rx_buf = imx->rx_buf;
- u32 rx_val;
for (i = 0; i < imx->xfer_len >> 2; i++) {
- rx_val = imx_xchg_single(spi, tx_buf ? tx_buf[i] : 0);
+ ret = imx_xchg_single(spi, tx_buf ? tx_buf[i] : 0, &rx_val);
+ if (ret)
+ return ret;
if (rx_buf)
rx_buf[i] = rx_val;
}
}
+
+ return 0;
}
static int cspi_2_3_xchg_burst(struct spi_device *spi)
@@ -448,7 +464,7 @@ static int cspi_2_3_xchg_burst(struct spi_device *spi)
return now;
}
-static void cspi_2_3_do_transfer(struct spi_device *spi)
+static int cspi_2_3_do_transfer(struct spi_device *spi)
{
struct imx_spi *imx = container_of(spi->master, struct imx_spi, master);
u32 ctrl;
@@ -457,14 +473,14 @@ static void cspi_2_3_do_transfer(struct spi_device *spi)
while (cspi_2_3_xchg_burst(spi) > 0);
if (!imx->xfer_len)
- return;
+ return 0;
ctrl = readl(imx->regs + CSPI_2_3_CTRL);
ctrl &= ~(0xfff << CSPI_2_3_CTRL_BL_OFFSET);
ctrl |= (spi->bits_per_word - 1) << CSPI_2_3_CTRL_BL_OFFSET;
writel(ctrl, imx->regs + CSPI_2_3_CTRL);
- imx_spi_do_transfer(spi);
+ return imx_spi_do_transfer(spi);
}
static int imx_spi_transfer(struct spi_device *spi, struct spi_message *mesg)
@@ -473,6 +489,7 @@ static int imx_spi_transfer(struct spi_device *spi, struct spi_message *mesg)
struct spi_transfer *t;
unsigned int cs_change;
const int nsecs = 50;
+ int ret;
imx->chipselect(spi, 1);
@@ -494,7 +511,9 @@ static int imx_spi_transfer(struct spi_device *spi, struct spi_message *mesg)
imx->rx_buf = t->rx_buf;
imx->xfer_len = t->len;
imx->bits_per_word = spi->bits_per_word;
- imx->do_transfer(spi);
+ ret = imx->do_transfer(spi);
+ if (ret)
+ return ret;
mesg->actual_length += t->len;
--
2.11.0
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