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path: root/drivers/spi/spi-pl022.c
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Diffstat (limited to 'drivers/spi/spi-pl022.c')
-rw-r--r--drivers/spi/spi-pl022.c58
1 files changed, 34 insertions, 24 deletions
diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
index 09c925a..400ae21 100644
--- a/drivers/spi/spi-pl022.c
+++ b/drivers/spi/spi-pl022.c
@@ -1667,9 +1667,15 @@ static int calculate_effective_freq(struct pl022 *pl022, int freq, struct
/* cpsdvsr = 254 & scr = 255 */
min_tclk = spi_rate(rate, CPSDVR_MAX, SCR_MAX);
- if (!((freq <= max_tclk) && (freq >= min_tclk))) {
+ if (freq > max_tclk)
+ dev_warn(&pl022->adev->dev,
+ "Max speed that can be programmed is %d Hz, you requested %d\n",
+ max_tclk, freq);
+
+ if (freq < min_tclk) {
dev_err(&pl022->adev->dev,
- "controller data is incorrect: out of range frequency");
+ "Requested frequency: %d Hz is less than minimum possible %d Hz\n",
+ freq, min_tclk);
return -EINVAL;
}
@@ -1681,26 +1687,37 @@ static int calculate_effective_freq(struct pl022 *pl022, int freq, struct
while (scr <= SCR_MAX) {
tmp = spi_rate(rate, cpsdvsr, scr);
- if (tmp > freq)
+ if (tmp > freq) {
+ /* we need lower freq */
scr++;
+ continue;
+ }
+
/*
- * If found exact value, update and break.
- * If found more closer value, update and continue.
+ * If found exact value, mark found and break.
+ * If found more closer value, update and break.
*/
- else if ((tmp == freq) || (tmp > best_freq)) {
+ if (tmp > best_freq) {
best_freq = tmp;
best_cpsdvsr = cpsdvsr;
best_scr = scr;
if (tmp == freq)
- break;
+ found = 1;
}
- scr++;
+ /*
+ * increased scr will give lower rates, which are not
+ * required
+ */
+ break;
}
cpsdvsr += 2;
scr = SCR_MIN;
}
+ WARN(!best_freq, "pl022: Matching cpsdvsr and scr not found for %d Hz rate \n",
+ freq);
+
clk_freq->cpsdvsr = (u8) (best_cpsdvsr & 0xFF);
clk_freq->scr = (u8) (best_scr & 0xFF);
dev_dbg(&pl022->adev->dev,
@@ -1823,9 +1840,12 @@ static int pl022_setup(struct spi_device *spi)
} else
chip->cs_control = chip_info->cs_control;
- if (bits <= 3) {
- /* PL022 doesn't support less than 4-bits */
+ /* Check bits per word with vendor specific range */
+ if ((bits <= 3) || (bits > pl022->vendor->max_bpw)) {
status = -ENOTSUPP;
+ dev_err(&spi->dev, "illegal data size for this controller!\n");
+ dev_err(&spi->dev, "This controller can only handle 4 <= n <= %d bit words\n",
+ pl022->vendor->max_bpw);
goto err_config_params;
} else if (bits <= 8) {
dev_dbg(&spi->dev, "4 <= n <=8 bits per word\n");
@@ -1838,20 +1858,10 @@ static int pl022_setup(struct spi_device *spi)
chip->read = READING_U16;
chip->write = WRITING_U16;
} else {
- if (pl022->vendor->max_bpw >= 32) {
- dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n");
- chip->n_bytes = 4;
- chip->read = READING_U32;
- chip->write = WRITING_U32;
- } else {
- dev_err(&spi->dev,
- "illegal data size for this controller!\n");
- dev_err(&spi->dev,
- "a standard pl022 can only handle "
- "1 <= n <= 16 bit words\n");
- status = -ENOTSUPP;
- goto err_config_params;
- }
+ dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n");
+ chip->n_bytes = 4;
+ chip->read = READING_U32;
+ chip->write = WRITING_U32;
}
/* Now Initialize all register settings required for this chip */