RE: [RFC PATCH 3/3] sdhci: arasan: Add support to read Tap Delay values from DT

Hi Adrian,

-----Original Message-----
From: Adrian Hunter [mailto:adrian.hunter@intel.com]
Sent: Tuesday, June 19, 2018 5:08 PM
To: Manish Narani <redacted>; robh+dt@kernel.org;
catalin.marinas@arm.com; will.deacon@arm.com; mdf@kernel.org;
stefan.krsmanovic@aggios.com; linux-arm-kernel@lists.infradead.org; linux-
kernel@vger.kernel.org; linux-mmc@vger.kernel.org;
devicetree@vger.kernel.org; Michal Simek [off-list ref];
ulf.hansson@linaro.org
Cc: Srinivas Goud <redacted>; Anirudha Sarangi
[off-list ref]
Subject: Re: [RFC PATCH 3/3] sdhci: arasan: Add support to read Tap Delay
values from DT

On 14/06/18 08:38, Manish Narani wrote:

quoted

Ping for RFC

What is eemi?  Why aren't there patches for that?

Eemi(Extensible Energy Management Interface) is a power management interface for ZynqMP core. The patches for the same are already in process of mainlining. 
https://lkml.org/lkml/2018/6/20/823

Thanks,
Manish

quoted

quoted

-----Original Message-----
From: Manish Narani [mailto:manish.narani@xilinx.com]
Sent: Thursday, June 7, 2018 5:42 PM
To: robh+dt@kernel.org; mark.rutland@arm.com;
catalin.marinas@arm.com; will.deacon@arm.com; mdf@kernel.org;
stefan.krsmanovic@aggios.com; linux-arm-kernel@lists.infradead.org;
linux-kernel@vger.kernel.org; linux- mmc@vger.kernel.org;
devicetree@vger.kernel.org; adrian.hunter@intel.com;
michal.simek@xilinx.com; ulf.hansson@linaro.org
Cc: Manish Narani <redacted>
Subject: [RFC PATCH 3/3] sdhci: arasan: Add support to read Tap Delay
values from DT

This patch adds support for reading Tap Delay values from Device Tree
and write them via eemi calls. The macros containing these tap delay
values are removed from the driver.

Signed-off-by: Manish Narani <redacted>
---
 drivers/mmc/host/sdhci-of-arasan.c | 131
+++++++++++++++++++++++++++++++++++++
 1 file changed, 131 insertions(+)

diff --git a/drivers/mmc/host/sdhci-of-arasan.c

b/drivers/mmc/host/sdhci- of-arasan.c index e3332a5..fc0fd01 100644

--- a/drivers/mmc/host/sdhci-of-arasan.c
+++ b/drivers/mmc/host/sdhci-of-arasan.c

@@ -36,6 +36,8 @@

 #define PHY_CLK_TOO_SLOW_HZ		400000

+#define MMC_BANK2		0x2
+
 /*
  * On some SoCs the syscon area has a feature where the upper 16-bits of
  * each 32-bit register act as a write mask for the lower 16-bits.

This allows @@ -90,6 +92,10 @@ struct sdhci_arasan_data {
 	struct sdhci_host *host;
 	struct clk	*clk_ahb;
 	struct phy	*phy;
+	u32 mio_bank;
+	u32 device_id;
+	u32 itapdly[MMC_TIMING_MMC_HS400 + 1];
+	u32 otapdly[MMC_TIMING_MMC_HS400 + 1];
 	bool		is_phy_on;

 	bool		has_cqe;

@@ -160,11 +166,36 @@ static int sdhci_arasan_syscon_write(struct

sdhci_host *host,
 	return ret;
 }

+/**
+ * arasan_zynqmp_set_tap_delay - Program the tap delays.
+ * @deviceid:		Unique Id of device
+ * @itap_delay:		Input Tap Delay
+ * @oitap_delay:	Output Tap Delay
+ */
+static void arasan_zynqmp_set_tap_delay(u8 deviceid, u8 itap_delay,
+u8
+otap_delay) {
+	const struct zynqmp_eemi_ops *eemi_ops =
zynqmp_pm_get_eemi_ops();
+	u32 node_id = (deviceid == 0) ? NODE_SD_0 : NODE_SD_1;
+
+	if (!eemi_ops || !eemi_ops->ioctl)
+		return;
+
+	if (itap_delay)
+		eemi_ops->ioctl(node_id, IOCTL_SET_SD_TAPDELAY,
+				PM_TAPDELAY_INPUT, itap_delay, NULL);
+
+	if (otap_delay)
+		eemi_ops->ioctl(node_id, IOCTL_SET_SD_TAPDELAY,
+				PM_TAPDELAY_OUTPUT, otap_delay, NULL);
}
+
 static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned
int
clock)  {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct sdhci_arasan_data *sdhci_arasan =
sdhci_pltfm_priv(pltfm_host);
 	bool ctrl_phy = false;
+	u8 itap_delay;
+	u8 otap_delay;

 	if (!IS_ERR(sdhci_arasan->phy)) {
 		if (!sdhci_arasan->is_phy_on && clock <=
PHY_CLK_TOO_SLOW_HZ) { @@ -200,6 +231,16 @@ static void
sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
 		}
 	}

+	if (host->version >= SDHCI_SPEC_300) {
+		if ((host->timing != MMC_TIMING_LEGACY) &&
+			(host->timing != MMC_TIMING_UHS_SDR12)) {
+			itap_delay = sdhci_arasan->itapdly[host->timing];
+			otap_delay = sdhci_arasan->otapdly[host->timing];
+			arasan_zynqmp_set_tap_delay(sdhci_arasan-

quoted

device_id,

+						    itap_delay, otap_delay);
+		}
+	}
+
 	if (ctrl_phy && sdhci_arasan->is_phy_on) {
 		phy_power_off(sdhci_arasan->phy);
 		sdhci_arasan->is_phy_on = false;

@@ -456,6 +497,7 @@ static const struct of_device_id

sdhci_arasan_of_match[] = {
 	{ .compatible = "arasan,sdhci-8.9a" },
 	{ .compatible = "arasan,sdhci-5.1" },
 	{ .compatible = "arasan,sdhci-4.9a" },
+	{ .compatible = "xlnx,zynqmp-8.9a" },

 	{ /* sentinel */ }
 };

@@ -641,6 +683,74 @@ static void sdhci_arasan_unregister_sdclk(struct

device *dev)
 	of_clk_del_provider(dev->of_node);
 }

+/**
+ * arasan_zynqmp_dt_parse_tap_delays - Read Tap Delay values from DT
+ *
+ * Called at initialization to parse the values of Tap Delays.
+ *
+ * @dev:		Pointer to our struct device.
+ */
+static void arasan_zynqmp_dt_parse_tap_delays(struct device *dev) {
+	struct platform_device *pdev = to_platform_device(dev);
+	struct sdhci_host *host = platform_get_drvdata(pdev);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_arasan_data *sdhci_arasan =
sdhci_pltfm_priv(pltfm_host);
+	struct device_node *np = dev->of_node;
+
+	of_property_read_u32(np, "xlnx,itap_delay_sd_hsd",
+			     &sdhci_arasan->itapdly[MMC_TIMING_SD_HS]);
+	of_property_read_u32(np, "xlnx,otap_delay_sd_hsd",
+			     &sdhci_arasan->otapdly[MMC_TIMING_SD_HS]);
+	of_property_read_u32(np, "xlnx,itap_delay_sdr25",
+			     &sdhci_arasan-

quoted

itapdly[MMC_TIMING_UHS_SDR25]);

+	of_property_read_u32(np, "xlnx,otap_delay_sdr25",
+			     &sdhci_arasan-

quoted

otapdly[MMC_TIMING_UHS_SDR25]);

+	of_property_read_u32(np, "xlnx,itap_delay_sdr50",
+			     &sdhci_arasan-

quoted

itapdly[MMC_TIMING_UHS_SDR50]);

+	of_property_read_u32(np, "xlnx,otap_delay_sdr50",
+			     &sdhci_arasan-

quoted

otapdly[MMC_TIMING_UHS_SDR50]);

+	of_property_read_u32(np, "xlnx,itap_delay_sd_ddr50",
+			     &sdhci_arasan-

quoted

itapdly[MMC_TIMING_UHS_DDR50]);

+	of_property_read_u32(np, "xlnx,otap_delay_sd_ddr50",
+			     &sdhci_arasan-

quoted

otapdly[MMC_TIMING_UHS_DDR50]);

+	of_property_read_u32(np, "xlnx,itap_delay_mmc_hsd",
+			     &sdhci_arasan-

quoted

itapdly[MMC_TIMING_MMC_HS]);

+	of_property_read_u32(np, "xlnx,otap_delay_mmc_hsd",
+			     &sdhci_arasan-

quoted

otapdly[MMC_TIMING_MMC_HS]);

+	of_property_read_u32(np, "xlnx,itap_delay_mmc_ddr50",
+			     &sdhci_arasan-

quoted

itapdly[MMC_TIMING_MMC_DDR52]);

+	of_property_read_u32(np, "xlnx,otap_delay_mmc_ddr50",
+			     &sdhci_arasan-

quoted

otapdly[MMC_TIMING_MMC_DDR52]);

+	if (sdhci_arasan->mio_bank == MMC_BANK2) {
+		of_property_read_u32(np,
+				     "xlnx,itap_delay_sdr104_b2",
+				&sdhci_arasan-

quoted

itapdly[MMC_TIMING_UHS_SDR104]);

+		of_property_read_u32(np,
+				     "xlnx,otap_delay_sdr104_b2",
+				&sdhci_arasan-

quoted

otapdly[MMC_TIMING_UHS_SDR104]);

+		of_property_read_u32(np,
+				     "xlnx,itap_delay_mmc_hs200_b2",
+				&sdhci_arasan-

quoted

itapdly[MMC_TIMING_MMC_HS200]);

+		of_property_read_u32(np,
+				     "xlnx,otap_delay_mmc_hs200_b2",
+				&sdhci_arasan-

quoted

otapdly[MMC_TIMING_MMC_HS200]);

+	} else {
+		of_property_read_u32(np,
+				     "xlnx,itap_delay_sdr104_b0",
+				&sdhci_arasan-

quoted

itapdly[MMC_TIMING_UHS_SDR104]);

+		of_property_read_u32(np,
+				     "xlnx,otap_delay_sdr104_b0",
+				&sdhci_arasan-

quoted

otapdly[MMC_TIMING_UHS_SDR104]);

+		of_property_read_u32(np,
+				     "xlnx,itap_delay_mmc_hs200_b0",
+				&sdhci_arasan-

quoted

itapdly[MMC_TIMING_MMC_HS200]);

+		of_property_read_u32(np,
+				     "xlnx,otap_delay_mmc_hs200_b0",
+				&sdhci_arasan-

quoted

otapdly[MMC_TIMING_MMC_HS200]);

+	}
+}
+
 static int sdhci_arasan_add_host(struct sdhci_arasan_data *sdhci_arasan)  {
 	struct sdhci_host *host = sdhci_arasan->host; @@ -776,6 +886,27 @@
static int sdhci_arasan_probe(struct platform_device *pdev)
 		goto unreg_clk;
 	}

+	if (of_device_is_compatible(pdev->dev.of_node,
+				    "xlnx,zynqmp-8.9a")) {
+		ret = of_property_read_u32(pdev->dev.of_node,
+					   "xlnx,mio_bank",
+					   &sdhci_arasan->mio_bank);
+		if (ret < 0) {
+			dev_err(&pdev->dev,
+				"\"xlnx,mio_bank \" property is missing.\n");
+			goto clk_disable_all;
+		}
+		ret = of_property_read_u32(pdev->dev.of_node,
+					   "xlnx,device_id",
+					   &sdhci_arasan->device_id);
+		if (ret < 0) {
+			dev_err(&pdev->dev,
+				"\"xlnx,device_id \" property is missing.\n");
+			goto clk_disable_all;
+		}
+		arasan_zynqmp_dt_parse_tap_delays(&pdev->dev);
+	}
+
 	sdhci_arasan->phy = ERR_PTR(-ENODEV);
 	if (of_device_is_compatible(pdev->dev.of_node,
 				    "arasan,sdhci-5.1")) {
--
2.7.4