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git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
spi: spi-fsl-lpspi: Some calculation improvements
Merge series from Stefan Wahren <wahrenst@gmx.net>:
This series contains some improvements for spi-fsl-lpspi which are
related to the calculations within fsl_lpspi_set_bitrate.
+11
-4
+11
-4
drivers/spi/spi-fsl-lpspi.c
+11
-4
drivers/spi/spi-fsl-lpspi.c
···
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u8 prescale;
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u16 mode;
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u32 speed_hz;
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+
u32 effective_speed_hz;
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};
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struct fsl_lpspi_data {
···
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static int fsl_lpspi_set_bitrate(struct fsl_lpspi_data *fsl_lpspi)
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{
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struct lpspi_config config = fsl_lpspi->config;
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-
unsigned int perclk_rate, scldiv, div;
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+
unsigned int perclk_rate, div;
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u8 prescale_max;
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u8 prescale;
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+
int scldiv;
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perclk_rate = clk_get_rate(fsl_lpspi->clk_per);
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prescale_max = fsl_lpspi->devtype_data->prescale_max;
···
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for (prescale = 0; prescale <= prescale_max; prescale++) {
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scldiv = div / (1 << prescale) - 2;
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-
if (scldiv < 256) {
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+
if (scldiv >= 0 && scldiv < 256) {
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fsl_lpspi->config.prescale = prescale;
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break;
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}
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}
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-
if (scldiv >= 256)
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+
if (scldiv < 0 || scldiv >= 256)
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return -EINVAL;
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writel(scldiv | (scldiv << 8) | ((scldiv >> 1) << 16),
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fsl_lpspi->base + IMX7ULP_CCR);
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-
dev_dbg(fsl_lpspi->dev, "perclk=%d, speed=%d, prescale=%d, scldiv=%d\n",
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+
fsl_lpspi->config.effective_speed_hz = perclk_rate / (scldiv + 2) *
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(1 << prescale);
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+
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dev_dbg(fsl_lpspi->dev, "perclk=%u, speed=%u, prescale=%u, scldiv=%d\n",
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perclk_rate, config.speed_hz, prescale, scldiv);
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return 0;
···
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ret = fsl_lpspi_setup_transfer(controller, spi, t);
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if (ret < 0)
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return ret;
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+
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+
t->effective_speed_hz = fsl_lpspi->config.effective_speed_hz;
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fsl_lpspi_set_cmd(fsl_lpspi);
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fsl_lpspi->is_first_byte = false;