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authorPaolo Bonzini <pbonzini@redhat.com>2021-09-06 12:34:11 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2021-09-06 12:34:48 +0200
commite99314a340d27efafab3b7ea226beb239162cd46 (patch)
treee16aebf4ddd982518c89eda4ccebdaff1c430723 /drivers/spi/spi-imx.c
parentMerge tag 'kvm-s390-next-5.15-1' of git://git.kernel.org/pub/scm/linux/kernel... (diff)
parentMerge branch kvm-arm64/misc-5.15 into kvmarm-master/next (diff)
downloadlinux-e99314a340d27efafab3b7ea226beb239162cd46.tar.xz
linux-e99314a340d27efafab3b7ea226beb239162cd46.zip
Merge tag 'kvmarm-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for 5.15 - Page ownership tracking between host EL1 and EL2 - Rely on userspace page tables to create large stage-2 mappings - Fix incompatibility between pKVM and kmemleak - Fix the PMU reset state, and improve the performance of the virtual PMU - Move over to the generic KVM entry code - Address PSCI reset issues w.r.t. save/restore - Preliminary rework for the upcoming pKVM fixed feature - A bunch of MM cleanups - a vGIC fix for timer spurious interrupts - Various cleanups
Diffstat (limited to 'drivers/spi/spi-imx.c')
-rw-r--r--drivers/spi/spi-imx.c38
1 files changed, 19 insertions, 19 deletions
diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 39dc02e366f4..4aee3db6d6df 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -506,7 +506,7 @@ static int mx51_ecspi_prepare_message(struct spi_imx_data *spi_imx,
{
struct spi_device *spi = msg->spi;
u32 ctrl = MX51_ECSPI_CTRL_ENABLE;
- u32 testreg;
+ u32 testreg, delay;
u32 cfg = readl(spi_imx->base + MX51_ECSPI_CONFIG);
/* set Master or Slave mode */
@@ -567,6 +567,23 @@ static int mx51_ecspi_prepare_message(struct spi_imx_data *spi_imx,
writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG);
+ /*
+ * Wait until the changes in the configuration register CONFIGREG
+ * propagate into the hardware. It takes exactly one tick of the
+ * SCLK clock, but we will wait two SCLK clock just to be sure. The
+ * effect of the delay it takes for the hardware to apply changes
+ * is noticable if the SCLK clock run very slow. In such a case, if
+ * the polarity of SCLK should be inverted, the GPIO ChipSelect might
+ * be asserted before the SCLK polarity changes, which would disrupt
+ * the SPI communication as the device on the other end would consider
+ * the change of SCLK polarity as a clock tick already.
+ */
+ delay = (2 * 1000000) / spi_imx->spi_bus_clk;
+ if (likely(delay < 10)) /* SCLK is faster than 100 kHz */
+ udelay(delay);
+ else /* SCLK is _very_ slow */
+ usleep_range(delay, delay + 10);
+
return 0;
}
@@ -574,7 +591,7 @@ static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx,
struct spi_device *spi)
{
u32 ctrl = readl(spi_imx->base + MX51_ECSPI_CTRL);
- u32 clk, delay;
+ u32 clk;
/* Clear BL field and set the right value */
ctrl &= ~MX51_ECSPI_CTRL_BL_MASK;
@@ -596,23 +613,6 @@ static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx,
writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
- /*
- * Wait until the changes in the configuration register CONFIGREG
- * propagate into the hardware. It takes exactly one tick of the
- * SCLK clock, but we will wait two SCLK clock just to be sure. The
- * effect of the delay it takes for the hardware to apply changes
- * is noticable if the SCLK clock run very slow. In such a case, if
- * the polarity of SCLK should be inverted, the GPIO ChipSelect might
- * be asserted before the SCLK polarity changes, which would disrupt
- * the SPI communication as the device on the other end would consider
- * the change of SCLK polarity as a clock tick already.
- */
- delay = (2 * 1000000) / clk;
- if (likely(delay < 10)) /* SCLK is faster than 100 kHz */
- udelay(delay);
- else /* SCLK is _very_ slow */
- usleep_range(delay, delay + 10);
-
return 0;
}