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spi: sh-msiof: Add reset of registers before starting transfer

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In accordance with hardware specification Ver 1.0, reset register
transmission / reception setting before transfer.

Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com>
[geert: Use readl_poll_timeout_atomic()]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Geert Uytterhoeven 2019-04-02 16:40:23 +02:00 committed by Mark Brown
parent 9115b4d89b
commit fedd694068
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GPG Key ID: 24D68B725D5487D0
1 changed files with 18 additions and 0 deletions
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18
drivers/spi/spi-sh-msiof.c
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@ -132,6 +132,8 @@ struct sh_msiof_spi_priv {
#define CTR_TFSE BIT(14) /* Transmit Frame Sync Signal Output Enable */
#define CTR_TXE BIT(9) /* Transmit Enable */
#define CTR_RXE BIT(8) /* Receive Enable */
#define CTR_TXRST BIT(1) /* Transmit Reset */
#define CTR_RXRST BIT(0) /* Receive Reset */
/* FCTR */
#define FCTR_TFWM_MASK GENMASK(31, 29) /* Transmit FIFO Watermark */
@ -241,6 +243,19 @@ static irqreturn_t sh_msiof_spi_irq(int irq, void *data)
return IRQ_HANDLED;
}
static void sh_msiof_spi_reset_regs(struct sh_msiof_spi_priv *p)
{
u32 mask = CTR_TXRST | CTR_RXRST;
u32 data;
data = sh_msiof_read(p, CTR);
data |= mask;
sh_msiof_write(p, CTR, data);
readl_poll_timeout_atomic(p->mapbase + CTR, data, !(data & mask), 1,
100);
}
static const u32 sh_msiof_spi_div_array[] = {
SCR_BRDV_DIV_1, SCR_BRDV_DIV_2, SCR_BRDV_DIV_4,
SCR_BRDV_DIV_8, SCR_BRDV_DIV_16, SCR_BRDV_DIV_32,
@ -920,6 +935,9 @@ static int sh_msiof_transfer_one(struct spi_controller *ctlr,
bool swab;
int ret;
/* reset registers */
sh_msiof_spi_reset_regs(p);
/* setup clocks (clock already enabled in chipselect()) */
if (!spi_controller_is_slave(p->ctlr))
sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk), t->speed_hz);