Hello. On 11/9/2016 3:56 AM, Vladimir Zapolskiy wrote:
The controller is capable to operate in up to PIO4 mode, however before the change the driver relies on timing settings done by a bootloader for PIO0 mode only. The change adds more flexibility in PIO mode selection at runtime and makes the driver to work even if
^^ not needed
bootloader does not preset ATA timings. Signed-off-by: Vladimir Zapolskiy <vz@xxxxxxxxx> --- drivers/ata/pata_imx.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 46 insertions(+), 1 deletion(-) diff --git a/drivers/ata/pata_imx.c b/drivers/ata/pata_imx.c index 00df18b..8f13c9f 100644 --- a/drivers/ata/pata_imx.c +++ b/drivers/ata/pata_imx.c
[...]
@@ -31,6 +40,10 @@ #define PATA_IMX_DRIVE_DATA 0xA0 #define PATA_IMX_DRIVE_CONTROL 0xD8 +static u32 pio_t4[] = { 30, 20, 15, 10, 10 }; +static u32 pio_t9[] = { 20, 15, 10, 10, 10 }; +static u32 pio_tA[] = { 35, 35, 35, 35, 35 };
Perhaps it makes sense to extend the 'struct ata_timing'... [...]
@@ -38,11 +51,43 @@ struct pata_imx_priv { u32 ata_ctl; }; +static void pata_imx_set_timing(struct ata_device *adev, + struct pata_imx_priv *priv) +{ + struct ata_timing timing; + unsigned long clkrate; + u32 T, mode; + + clkrate = clk_get_rate(priv->clk); + + if (adev->pio_mode < XFER_PIO_0 || adev->pio_mode > XFER_PIO_4 || + !clkrate) + return; + + T = 1000000000 / clkrate; + ata_timing_compute(adev, adev->pio_mode, &timing, T * 1000, 0); + + mode = adev->pio_mode - XFER_PIO_0; + + writeb(3, priv->host_regs + PATA_IMX_ATA_TIME_OFF); + writeb(3, priv->host_regs + PATA_IMX_ATA_TIME_ON);
What do those registers mean?
+ writeb(timing.setup, priv->host_regs + PATA_IMX_ATA_TIME_1); + writeb(timing.act8b, priv->host_regs + PATA_IMX_ATA_TIME_2W); + writeb(timing.act8b, priv->host_regs + PATA_IMX_ATA_TIME_2R); + writeb(1, priv->host_regs + PATA_IMX_ATA_TIME_PIO_RDX);
And this one?
+ + writeb(pio_t4[mode] / T + 1, priv->host_regs + PATA_IMX_ATA_TIME_4); + writeb(pio_t9[mode] / T + 1, priv->host_regs + PATA_IMX_ATA_TIME_9); + writeb(pio_tA[mode] / T + 1, priv->host_regs + PATA_IMX_ATA_TIME_AX);
DIV_ROUND_UP(x, T)? [...] MBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html