Some devices need delays before and after activiation. Implement these features in the SPI driver so that we will be able to enable the Chrome OS EC.
Signed-off-by: Simon Glass sjg@chromium.org ---
drivers/spi/rk_spi.c | 27 +++++++++++++++++++++++---- 1 file changed, 23 insertions(+), 4 deletions(-)
diff --git a/drivers/spi/rk_spi.c b/drivers/spi/rk_spi.c index 2570ca3..91538b4 100644 --- a/drivers/spi/rk_spi.c +++ b/drivers/spi/rk_spi.c @@ -32,6 +32,7 @@ struct rockchip_spi_platdata { s32 frequency; /* Default clock frequency, -1 for none */ fdt_addr_t base; uint deactivate_delay_us; /* Delay to wait after deactivate */ + uint activate_delay_us; /* Delay to wait after activate */ };
struct rockchip_spi_priv { @@ -101,16 +102,32 @@ static int rkspi_wait_till_not_busy(struct rockchip_spi *regs) return 0; }
-static void spi_cs_activate(struct rockchip_spi *regs, uint cs) +static void spi_cs_activate(struct udevice *dev, uint cs) { + struct udevice *bus = dev->parent; + struct rockchip_spi_platdata *plat = bus->platdata; + struct rockchip_spi_priv *priv = dev_get_priv(bus); + struct rockchip_spi *regs = priv->regs; + debug("activate cs%u\n", cs); writel(1 << cs, ®s->ser); + if (plat->activate_delay_us) + udelay(plat->activate_delay_us); }
-static void spi_cs_deactivate(struct rockchip_spi *regs, uint cs) +static void spi_cs_deactivate(struct udevice *dev, uint cs) { + struct udevice *bus = dev->parent; + struct rockchip_spi_platdata *plat = bus->platdata; + struct rockchip_spi_priv *priv = dev_get_priv(bus); + struct rockchip_spi *regs = priv->regs; + debug("deactivate cs%u\n", cs); writel(0, ®s->ser); + + /* Remember time of this transaction so we can honour the bus delay */ + if (plat->deactivate_delay_us) + priv->last_transaction_us = timer_get_us(); }
static int rockchip_spi_ofdata_to_platdata(struct udevice *bus) @@ -144,6 +161,8 @@ static int rockchip_spi_ofdata_to_platdata(struct udevice *bus) 50000000); plat->deactivate_delay_us = fdtdec_get_int(blob, node, "spi-deactivate-delay", 0); + plat->activate_delay_us = fdtdec_get_int(blob, node, + "spi-activate-delay", 0); debug("%s: base=%x, periph_id=%d, max-frequency=%d, deactivate_delay=%d\n", __func__, (uint)plat->base, plat->periph_id, plat->frequency, plat->deactivate_delay_us); @@ -289,7 +308,7 @@ static int rockchip_spi_xfer(struct udevice *dev, unsigned int bitlen,
/* Assert CS before transfer */ if (flags & SPI_XFER_BEGIN) - spi_cs_activate(regs, slave_plat->cs); + spi_cs_activate(dev, slave_plat->cs);
while (len > 0) { int todo = min(len, 0xffff); @@ -323,7 +342,7 @@ static int rockchip_spi_xfer(struct udevice *dev, unsigned int bitlen,
/* Deassert CS after transfer */ if (flags & SPI_XFER_END) - spi_cs_deactivate(regs, slave_plat->cs); + spi_cs_deactivate(dev, slave_plat->cs);
rkspi_enable_chip(regs, false);