Re: [U-Boot] [PATCH] zynq: spi: Honour the activation / deactivation delay

Whoops,

On Thu, Dec 8, 2016 at 12:11 PM, Moritz Fischer moritz.fischer@ettus.com wrote:

This is not currently implemented. Add support for this so that the Chrome OS EC can be used reliably.

Signed-off-by: Moritz Fischer moritz.fischer@ettus.com Cc: Jagan Teki jagan@openedev.com Cc: Simon Glass sjg@chromium.org Cc: u-boot@lists.denx.de

Cc: Michal Simek michal.simek@xilinx.com

---

drivers/spi/zynq_spi.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+)

diff --git a/drivers/spi/zynq_spi.c b/drivers/spi/zynq_spi.c index 15ca271..5e7954c 100644 --- a/drivers/spi/zynq_spi.c +++ b/drivers/spi/zynq_spi.c @@ -56,6 +56,8 @@ struct zynq_spi_platdata { struct zynq_spi_regs *regs; u32 frequency; /* input frequency */ u32 speed_hz;

•   uint deactivate_delay_us;       /* Delay to wait after deactivate */
  

•   uint activate_delay_us;         /* Delay to wait after activate */
  

};

/* zynq spi priv */ @@ -63,6 +65,7 @@ struct zynq_spi_priv { struct zynq_spi_regs *regs; u8 cs; u8 mode;

•   ulong last_transaction_us;      /* Time of last transaction end */
    u8 fifo_depth;
    u32 freq;               /* required frequency */
  

}; @@ -78,6 +81,10 @@ static int zynq_spi_ofdata_to_platdata(struct udevice *bus) /* FIXME: Use 250MHz as a suitable default */ plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency", 250000000);

•   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);
    plat->speed_hz = plat->frequency / 2;
  
    debug("%s: regs=%p max-frequency=%d\n", __func__,
  

@@ -133,10 +140,19 @@ static int zynq_spi_probe(struct udevice *bus) static void spi_cs_activate(struct udevice *dev) { struct udevice *bus = dev->parent;

•   struct zynq_spi_platdata *plat = bus->platdata;
    struct zynq_spi_priv *priv = dev_get_priv(bus);
    struct zynq_spi_regs *regs = priv->regs;
    u32 cr;
  
  

•   /* If it's too soon to do another transaction, wait */
  

•   if (plat->deactivate_delay_us && priv->last_transaction_us) {
  

•           ulong delay_us;         /* The delay completed so far */
  

•           delay_us = timer_get_us() - priv->last_transaction_us;
  

•           if (delay_us < plat->deactivate_delay_us)
  

•                   udelay(plat->deactivate_delay_us - delay_us);
  

•   }
  

•   clrbits_le32(&regs->cr, ZYNQ_SPI_CR_CS_MASK);
    cr = readl(&regs->cr);
    /*
  

@@ -147,15 +163,23 @@ static void spi_cs_activate(struct udevice *dev) */ cr |= (~(1 << priv->cs) << ZYNQ_SPI_CR_SS_SHIFT) & ZYNQ_SPI_CR_CS_MASK; writel(cr, &regs->cr);

•   if (plat->activate_delay_us)
  

•           udelay(plat->activate_delay_us);
  

}

static void spi_cs_deactivate(struct udevice *dev) { struct udevice *bus = dev->parent;

•   struct zynq_spi_platdata *plat = bus->platdata;
    struct zynq_spi_priv *priv = dev_get_priv(bus);
    struct zynq_spi_regs *regs = priv->regs;
  
    setbits_le32(&regs->cr, ZYNQ_SPI_CR_CS_MASK);
  

•   /* 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 zynq_spi_claim_bus(struct udevice *dev)

2.7.4

Thanks,

Moritz