rockchip: spi: Implement the delays

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>

diff --git a/drivers/spi/rk_spi.c b/drivers/spi/rk_spi.c
index 3418f9b0805179a951ce52cdef40027f8d2ac8cf..35b528fa59d6d059a1c5f8d6c1813da1637265b3 100644 (file)
--- 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, &regs->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, &regs->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)
@@ -145,6 +162,8 @@ 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);
@@ -290,7 +309,7 @@ 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);
@@ -324,7 +343,7 @@ 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);