spi: spi_sh_msiof: Fixed data sampling on the correct edge
The spi_sh_msiof.c driver presently misconfigures REDG and TEDG. TEDG==0 outputs data at the **rising edge** of the clock and REDG==0 samples data at the **falling edge** of the clock. Therefore for SPI, TEDG must be equal to REDG, otherwise the last byte received is not sampled in SPI mode 3. This brings the driver in line with the SH7723 HW Reference Manual settings documented in Figures 20.20 and 20.21 ("SPI Clock and data timing"). Signed-off-by: Markus Pietrek <Markus.Pietrek@emtrion.de> Acked-by: Magnus Damm <damm@opensource.se> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
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@ -173,15 +173,12 @@ static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
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int edge;
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/*
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* CPOL CPHA TSCKIZ RSCKIZ TEDG REDG(!)
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* 0 0 10 10 1 0
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* 0 1 10 10 0 1
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* 1 0 11 11 0 1
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* 1 1 11 11 1 0
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*
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* (!) Note: REDG is inverted recommended data sheet setting
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* CPOL CPHA TSCKIZ RSCKIZ TEDG REDG
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* 0 0 10 10 1 1
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* 0 1 10 10 0 0
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* 1 0 11 11 0 0
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* 1 1 11 11 1 1
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*/
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sh_msiof_write(p, FCTR, 0);
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sh_msiof_write(p, TMDR1, 0xe2000005 | (lsb_first << 24));
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sh_msiof_write(p, RMDR1, 0x22000005 | (lsb_first << 24));
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@ -193,7 +190,7 @@ static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
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edge = cpol ? cpha : !cpha;
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tmp |= edge << 27; /* TEDG */
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tmp |= !edge << 26; /* REDG */
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tmp |= edge << 26; /* REDG */
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tmp |= (tx_hi_z ? 2 : 0) << 22; /* TXDIZ */
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sh_msiof_write(p, CTR, tmp);
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}
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