From: Shawn Lin <shawn.lin@rock-chips.com>
To: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Rob Herring <robh+dt@kernel.org>,
devicetree@vger.kernel.org, linux-rockchip@lists.infradead.org,
Heiko Stuebner <heiko@sntech.de>,
Douglas Anderson <dianders@chromium.org>,
linux-kernel@vger.kernel.org,
Shawn Lin <shawn.lin@rock-chips.com>
Subject: [PATCH 2/2] phy: rockchip-emmc: try to get drive impedance from DT
Date: Thu, 5 Jan 2017 17:31:22 +0800 [thread overview]
Message-ID: <1483608682-226716-2-git-send-email-shawn.lin@rock-chips.com> (raw)
In-Reply-To: <1483608682-226716-1-git-send-email-shawn.lin@rock-chips.com>
Try to get drive impedance from DT and use it, otherwise
use 50ohm by default in order not to break the existing boards
as 50ohm works fine for them already.
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
---
drivers/phy/phy-rockchip-emmc.c | 29 ++++++++++++++++++++++++++++-
1 file changed, 28 insertions(+), 1 deletion(-)
diff --git a/drivers/phy/phy-rockchip-emmc.c b/drivers/phy/phy-rockchip-emmc.c
index f1b24f1..7fd4a3e 100644
--- a/drivers/phy/phy-rockchip-emmc.c
+++ b/drivers/phy/phy-rockchip-emmc.c
@@ -78,6 +78,7 @@
struct rockchip_emmc_phy {
unsigned int reg_offset;
+ unsigned int drive_impedance;
struct regmap *reg_base;
struct clk *emmcclk;
};
@@ -288,7 +289,7 @@ static int rockchip_emmc_phy_power_on(struct phy *phy)
/* Drive impedance: 50 Ohm */
regmap_write(rk_phy->reg_base,
rk_phy->reg_offset + GRF_EMMCPHY_CON6,
- HIWORD_UPDATE(PHYCTRL_DR_50OHM,
+ HIWORD_UPDATE(rk_phy->drive_impedance,
PHYCTRL_DR_MASK,
PHYCTRL_DR_SHIFT));
@@ -346,6 +347,32 @@ static int rockchip_emmc_phy_probe(struct platform_device *pdev)
return -EINVAL;
}
+ rk_phy->drive_impedance = PHYCTRL_DR_50OHM;
+ if (!of_property_read_u32(dev->of_node, "drive_impedance",
+ &rk_phy->drive_impedance)) {
+ switch (rk_phy->drive_impedance) {
+ case 33:
+ rk_phy->drive_impedance = PHYCTRL_DR_33OHM;
+ break;
+ case 40:
+ rk_phy->drive_impedance = PHYCTRL_DR_40OHM;
+ break;
+ case 50:
+ rk_phy->drive_impedance = PHYCTRL_DR_50OHM;
+ break;
+ case 66:
+ rk_phy->drive_impedance = PHYCTRL_DR_66OHM;
+ break;
+ case 100:
+ rk_phy->drive_impedance = PHYCTRL_DR_100OHM;
+ break;
+ default:
+ dev_info(dev, "invalid drive impedance.\n");
+ rk_phy->drive_impedance = PHYCTRL_DR_50OHM;
+ break;
+ }
+ }
+
rk_phy->reg_offset = reg_offset;
rk_phy->reg_base = grf;
--
1.9.1
next prev parent reply other threads:[~2017-01-05 9:34 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-05 9:31 [PATCH 1/2] Documentation: phy: introduce new optional property to specify drive impedance Shawn Lin
2017-01-05 9:31 ` Shawn Lin [this message]
2017-01-06 0:51 ` [PATCH 2/2] phy: rockchip-emmc: try to get drive impedance from DT Doug Anderson
2017-01-06 1:09 ` Shawn Lin
2017-01-06 18:29 ` Doug Anderson
2017-01-05 11:15 ` [PATCH 1/2] Documentation: phy: introduce new optional property to specify drive impedance Heiko Stübner
2017-01-06 0:44 ` Shawn Lin
2017-01-09 18:06 ` Rob Herring
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