From: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
To: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
Andrew Murray <andrew.murray@arm.com>,
Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
Masami Hiramatsu <masami.hiramatsu@linaro.org>,
Jassi Brar <jaswinder.singh@linaro.org>,
Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Subject: [PATCH 2/2] PCI: uniphier: Add checking whether PERST# is deasserted
Date: Thu, 7 Nov 2019 13:58:15 +0900 [thread overview]
Message-ID: <1573102695-7018-2-git-send-email-hayashi.kunihiko@socionext.com> (raw)
In-Reply-To: <1573102695-7018-1-git-send-email-hayashi.kunihiko@socionext.com>
When PERST# is asserted once, EP configuration will be initialized.
If PERST# has been already deasserted, it isn't necessary to assert
here.
This checks whether PERST# is deasserted using PCL_PINMON register,
and adds omit controlling PERST#.
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
---
drivers/pci/controller/dwc/pcie-uniphier.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/pci/controller/dwc/pcie-uniphier.c b/drivers/pci/controller/dwc/pcie-uniphier.c
index 8fd7bad..1ea4220 100644
--- a/drivers/pci/controller/dwc/pcie-uniphier.c
+++ b/drivers/pci/controller/dwc/pcie-uniphier.c
@@ -22,6 +22,9 @@
#include "pcie-designware.h"
+#define PCL_PINMON 0x0028
+#define PCL_PINMON_PERST_OUT BIT(16)
+
#define PCL_PINCTRL0 0x002c
#define PCL_PERST_PLDN_REGEN BIT(12)
#define PCL_PERST_NOE_REGEN BIT(11)
@@ -100,6 +103,11 @@ static void uniphier_pcie_init_rc(struct uniphier_pcie_priv *priv)
val |= PCL_SYS_AUX_PWR_DET;
writel(val, priv->base + PCL_APP_PM0);
+ /* return if PERST# is already deasserted */
+ val = readl(priv->base + PCL_PINMON);
+ if (val & PCL_PINMON_PERST_OUT)
+ return;
+
/* assert PERST# */
val = readl(priv->base + PCL_PINCTRL0);
val &= ~(PCL_PERST_NOE_REGVAL | PCL_PERST_OUT_REGVAL
--
2.7.4
next prev parent reply other threads:[~2019-11-07 4:59 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-07 4:58 [PATCH 1/2] PCI: uniphier: Set mode register to host mode Kunihiko Hayashi
2019-11-07 4:58 ` Kunihiko Hayashi [this message]
2019-11-07 10:02 ` [PATCH 2/2] PCI: uniphier: Add checking whether PERST# is deasserted Andrew Murray
2019-11-07 11:52 ` Kunihiko Hayashi
2019-11-07 12:46 ` Andrew Murray
2019-11-08 7:30 ` Kunihiko Hayashi
2019-11-08 9:59 ` Andrew Murray
2019-11-21 16:47 ` Lorenzo Pieralisi
2019-11-22 11:53 ` Kunihiko Hayashi
2019-12-04 10:05 ` Kunihiko Hayashi
2019-12-06 6:58 ` Kishon Vijay Abraham I
2019-12-06 8:58 ` Kunihiko Hayashi
2019-12-06 9:01 ` Kishon Vijay Abraham I
2019-12-09 2:35 ` Kunihiko Hayashi
2019-11-07 9:52 ` [PATCH 1/2] PCI: uniphier: Set mode register to host mode Andrew Murray
2019-11-21 16:49 ` Lorenzo Pieralisi
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