在 2022/7/2 11:09, qianfan 写道:
在 2022/6/28 8:34, Andre Przywara 写道:
On Thu, 9 Jun 2022 17:09:39 +0800 qianfanguijin@163.com wrote:
Hi Qianfan,
From: qianfan Zhao qianfanguijin@163.com
dm_spi_claim_bus run spi_set_speed_mode first and then ops->claim_bus, but spi clock is enabled when sun4i_spi_claim_bus, that will make sun4i_spi_set_speed doesn't work.
Thanks for bringing this up, and sorry for the delay (please CC: the U-Boot sunxi maintainers!). So this is very similar to the patch as I sent earlier: https://lore.kernel.org/u-boot/20220503212040.27884-3-andre.przywara@arm.com...
Can you please check whether this works for you as well, then reply to that patch? I put my version of the patch plus more fixes and F1C100s support to: https://source.denx.de/u-boot/custodians/u-boot-sunxi/-/commits/next/
Also I am curious under what circumstances and on what board you saw the issue? In my case it was on the F1C100s, which has a higher base clock (200 MHz instead of 24 MHz), so everything gets badly overclocked.
I tested based on those two commits:
spi: sunxi: refactor SPI speed/mode programming spi: sunxi: improve SPI clock calculation
And there are a couple of questions:
- sun4i_spi_of_to_plat try reading "spi-max-frequency" from the spi
bus node:
static int sun4i_spi_of_to_plat(struct udevice *bus) { struct sun4i_spi_plat *plat = dev_get_plat(bus); int node = dev_of_offset(bus);
plat->base = dev_read_addr(bus); plat->variant = (struct sun4i_spi_variant *)dev_get_driver_data(bus); plat->max_hz = fdtdec_get_int(gd->fdt_blob, node, "spi-max-frequency", SUN4I_SPI_DEFAULT_RATE);
if (plat->max_hz > SUN4I_SPI_MAX_RATE) plat->max_hz = SUN4I_SPI_MAX_RATE;
return 0; }
Seems this is not a correct way. "spi-max-frequency" should reading from spi device, not spi bus. On my dts, no "spi-max-frequency" prop on spi bus node, this will make plat->max_hz has default SUN4I_SPI_DEFAULT_RATE(1M) value.
&spi2 { pinctrl-names = "default"; pinctrl-0 = <&spi2_cs0_pb_pin &spi2_pb_pins>; status = "okay";
lcd@0 { compatible = "sitronix,st75161"; spi-max-frequency = <12000000>; reg = <0>; spi-cpol; spi-cpha;
So on my patch, I had changed the default plat->max_hz to SUN4I_SPI_MAX_RATE.
- When I changed the default plat->max_hz to SUN4I_SPI_MAX_RATE:
2.1: sun4i_spi_set_speed_mode doesn't consider when div = 1(freq = SUNXI_INPUT_CLOCK), the spi running in 12M even if the spi-max-frequency is setted to 24M.
2.2: on my R40 based board, spi can't work when the spi clock <= 6M. I had check the CCR register, the value is correct, from logic analyzer only the first byte is sent. Next is the serial console logs:
spi clock = 6M: CCR: 00001001 ERROR: sun4i_spi: Timeout transferring data ERROR: sun4i_spi: Timeout transferring data ERROR: sun4i_spi: Timeout transferring data ...
spi clock = 4M: CCR: 00001002 ERROR: sun4i_spi: Timeout transferring data ERROR: sun4i_spi: Timeout transferring data ERROR: sun4i_spi: Timeout transferring data ERROR: sun4i_spi: Timeout transferring data ERROR: sun4i_spi: Timeout transferring data ...
Add udelay(1) before sun4i_spi_drain_fifo in sun4i_spi_xfer can fix it. But I don't know why.
Thanks! Andre
Fix it.
Signed-off-by: qianfan Zhao qianfanguijin@163.com
drivers/spi/spi-sunxi.c | 78 ++++++++++++++++------------------------- 1 file changed, 30 insertions(+), 48 deletions(-)
diff --git a/drivers/spi/spi-sunxi.c b/drivers/spi/spi-sunxi.c index b6cd7ddafa..1043cde976 100644 --- a/drivers/spi/spi-sunxi.c +++ b/drivers/spi/spi-sunxi.c @@ -224,6 +224,7 @@ err_ahb: static int sun4i_spi_claim_bus(struct udevice *dev) { struct sun4i_spi_priv *priv = dev_get_priv(dev->parent); + u32 div, reg; int ret; ret = sun4i_spi_set_clock(dev->parent, true); @@ -233,12 +234,38 @@ static int sun4i_spi_claim_bus(struct udevice *dev) setbits_le32(SPI_REG(priv, SPI_GCR), SUN4I_CTL_ENABLE | SUN4I_CTL_MASTER | SPI_BIT(priv, SPI_GCR_TP)); + /* Setup clock divider */ + div = SUN4I_SPI_MAX_RATE / (2 * priv->freq); + reg = readl(SPI_REG(priv, SPI_CCR));
+ if (div <= (SUN4I_CLK_CTL_CDR2_MASK + 1)) { + if (div > 0) + div--;
+ reg &= ~(SUN4I_CLK_CTL_CDR2_MASK | SUN4I_CLK_CTL_DRS); + reg |= SUN4I_CLK_CTL_CDR2(div) | SUN4I_CLK_CTL_DRS; + } else { + div = __ilog2(SUN4I_SPI_MAX_RATE) - __ilog2(priv->freq); + reg &= ~((SUN4I_CLK_CTL_CDR1_MASK << 8) | SUN4I_CLK_CTL_DRS); + reg |= SUN4I_CLK_CTL_CDR1(div); + }
+ writel(reg, SPI_REG(priv, SPI_CCR));
if (priv->variant->has_soft_reset) setbits_le32(SPI_REG(priv, SPI_GCR), SPI_BIT(priv, SPI_GCR_SRST)); - setbits_le32(SPI_REG(priv, SPI_TCR), SPI_BIT(priv, SPI_TCR_CS_MANUAL) | - SPI_BIT(priv, SPI_TCR_CS_ACTIVE_LOW)); + /* Setup the transfer control register */ + reg = SPI_BIT(priv, SPI_TCR_CS_MANUAL) | + SPI_BIT(priv, SPI_TCR_CS_ACTIVE_LOW);
+ if (priv->mode & SPI_CPOL) + reg |= SPI_BIT(priv, SPI_TCR_CPOL); + if (priv->mode & SPI_CPHA) + reg |= SPI_BIT(priv, SPI_TCR_CPHA);
+ writel(reg, SPI_REG(priv, SPI_TCR)); return 0; } @@ -329,67 +356,22 @@ static int sun4i_spi_set_speed(struct udevice *dev, uint speed) { struct sun4i_spi_plat *plat = dev_get_plat(dev); struct sun4i_spi_priv *priv = dev_get_priv(dev); - unsigned int div; - u32 reg; if (speed > plat->max_hz) speed = plat->max_hz; if (speed < SUN4I_SPI_MIN_RATE) speed = SUN4I_SPI_MIN_RATE; - /* - * Setup clock divider. - * - * We have two choices there. Either we can use the clock - * divide rate 1, which is calculated thanks to this formula: - * SPI_CLK = MOD_CLK / (2 ^ (cdr + 1)) - * Or we can use CDR2, which is calculated with the formula: - * SPI_CLK = MOD_CLK / (2 * (cdr + 1)) - * Whether we use the former or the latter is set through the - * DRS bit. - * - * First try CDR2, and if we can't reach the expected - * frequency, fall back to CDR1. - */
- div = SUN4I_SPI_MAX_RATE / (2 * speed); - reg = readl(SPI_REG(priv, SPI_CCR));
- if (div <= (SUN4I_CLK_CTL_CDR2_MASK + 1)) { - if (div > 0) - div--;
- reg &= ~(SUN4I_CLK_CTL_CDR2_MASK | SUN4I_CLK_CTL_DRS); - reg |= SUN4I_CLK_CTL_CDR2(div) | SUN4I_CLK_CTL_DRS; - } else { - div = __ilog2(SUN4I_SPI_MAX_RATE) - __ilog2(speed); - reg &= ~((SUN4I_CLK_CTL_CDR1_MASK << 8) | SUN4I_CLK_CTL_DRS); - reg |= SUN4I_CLK_CTL_CDR1(div); - } priv->freq = speed; - writel(reg, SPI_REG(priv, SPI_CCR));
return 0; } static int sun4i_spi_set_mode(struct udevice *dev, uint mode) { struct sun4i_spi_priv *priv = dev_get_priv(dev); - u32 reg;
- reg = readl(SPI_REG(priv, SPI_TCR)); - reg &= ~(SPI_BIT(priv, SPI_TCR_CPOL) | SPI_BIT(priv, SPI_TCR_CPHA));
- if (mode & SPI_CPOL) - reg |= SPI_BIT(priv, SPI_TCR_CPOL);
- if (mode & SPI_CPHA) - reg |= SPI_BIT(priv, SPI_TCR_CPHA); priv->mode = mode; - writel(reg, SPI_REG(priv, SPI_TCR));
return 0; } @@ -441,7 +423,7 @@ static int sun4i_spi_of_to_plat(struct udevice *bus) plat->variant = (struct sun4i_spi_variant *)dev_get_driver_data(bus); plat->max_hz = fdtdec_get_int(gd->fdt_blob, node, "spi-max-frequency", - SUN4I_SPI_DEFAULT_RATE); + SUN4I_SPI_MAX_RATE); if (plat->max_hz > SUN4I_SPI_MAX_RATE) plat->max_hz = SUN4I_SPI_MAX_RATE;