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From: srinivas.kandagatla@linaro.org
To: gregkh@linuxfoundation.org
Cc: linux-kernel@vger.kernel.org, srinivas.kandagatla@linaro.org,
	Icenowy Zheng <icenowy@aosc.io>
Subject: [PATCH 23/25] nvmem: sunxi-sid: fix H3 SID controller support
Date: Fri,  9 Mar 2018 14:47:17 +0000	[thread overview]
Message-ID: <20180309144719.29904-24-srinivas.kandagatla@linaro.org> (raw)
In-Reply-To: <20180309144719.29904-1-srinivas.kandagatla@linaro.org>

From: Icenowy Zheng <icenowy@aosc.io>

It seems that doing some operation will make the value pre-read on H3
SID controller wrong again, so all operation should be performed by
register.

Change the SID reading to use register only.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 drivers/nvmem/sunxi_sid.c | 71 +++++++++++++++++++++++++++++++++--------------
 1 file changed, 50 insertions(+), 21 deletions(-)

diff --git a/drivers/nvmem/sunxi_sid.c b/drivers/nvmem/sunxi_sid.c
index 99bd54d85fcb..26bb637afe92 100644
--- a/drivers/nvmem/sunxi_sid.c
+++ b/drivers/nvmem/sunxi_sid.c
@@ -85,13 +85,14 @@ static int sunxi_sid_read(void *context, unsigned int offset,
 }
 
 static int sun8i_sid_register_readout(const struct sunxi_sid *sid,
-				      const unsigned int word)
+				      const unsigned int offset,
+				      u32 *out)
 {
 	u32 reg_val;
 	int ret;
 
 	/* Set word, lock access, and set read command */
-	reg_val = (word & SUN8I_SID_OFFSET_MASK)
+	reg_val = (offset & SUN8I_SID_OFFSET_MASK)
 		  << SUN8I_SID_OFFSET_SHIFT;
 	reg_val |= SUN8I_SID_OP_LOCK | SUN8I_SID_READ;
 	writel(reg_val, sid->base + SUN8I_SID_PRCTL);
@@ -101,7 +102,49 @@ static int sun8i_sid_register_readout(const struct sunxi_sid *sid,
 	if (ret)
 		return ret;
 
+	if (out)
+		*out = readl(sid->base + SUN8I_SID_RDKEY);
+
 	writel(0, sid->base + SUN8I_SID_PRCTL);
+
+	return 0;
+}
+
+/*
+ * On Allwinner H3, the value on the 0x200 offset of the SID controller seems
+ * to be not reliable at all.
+ * Read by the registers instead.
+ */
+static int sun8i_sid_read_byte_by_reg(const struct sunxi_sid *sid,
+				      const unsigned int offset,
+				      u8 *out)
+{
+	u32 word;
+	int ret;
+
+	ret = sun8i_sid_register_readout(sid, offset & ~0x03, &word);
+
+	if (ret)
+		return ret;
+
+	*out = (word >> ((offset & 0x3) * 8)) & 0xff;
+
+	return 0;
+}
+
+static int sun8i_sid_read_by_reg(void *context, unsigned int offset,
+				 void *val, size_t bytes)
+{
+	struct sunxi_sid *sid = context;
+	u8 *buf = val;
+	int ret;
+
+	while (bytes--) {
+		ret = sun8i_sid_read_byte_by_reg(sid, offset++, buf++);
+		if (ret)
+			return ret;
+	}
+
 	return 0;
 }
 
@@ -131,26 +174,12 @@ static int sunxi_sid_probe(struct platform_device *pdev)
 
 	size = cfg->size;
 
-	if (cfg->need_register_readout) {
-		/*
-		 * H3's SID controller have a bug that the value at 0x200
-		 * offset is not the correct value when the hardware is reseted.
-		 * However, after doing a register-based read operation, the
-		 * value become right.
-		 * Do a full read operation here, but ignore its value
-		 * (as it's more fast to read by direct MMIO value than
-		 * with registers)
-		 */
-		for (i = 0; i < (size >> 2); i++) {
-			ret = sun8i_sid_register_readout(sid, i);
-			if (ret)
-				return ret;
-		}
-	}
-
 	econfig.size = size;
 	econfig.dev = dev;
-	econfig.reg_read = sunxi_sid_read;
+	if (cfg->need_register_readout)
+		econfig.reg_read = sun8i_sid_read_by_reg;
+	else
+		econfig.reg_read = sunxi_sid_read;
 	econfig.priv = sid;
 	nvmem = nvmem_register(&econfig);
 	if (IS_ERR(nvmem))
@@ -163,7 +192,7 @@ static int sunxi_sid_probe(struct platform_device *pdev)
 	}
 
 	for (i = 0; i < size; i++)
-		randomness[i] = sunxi_sid_read_byte(sid, i);
+		econfig.reg_read(sid, i, &randomness[i], 1);
 
 	add_device_randomness(randomness, size);
 	kfree(randomness);
-- 
2.15.1

  parent reply	other threads:[~2018-03-09 14:47 UTC|newest]

Thread overview: 73+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-09 14:46 [PATCH 00/25] nvmem: patches for v4.17 srinivas.kandagatla
2018-03-09 14:46 ` [PATCH 01/25] nvmem: Document struct nvmem_config srinivas.kandagatla
2018-03-09 14:46   ` srinivas.kandagatla at linaro.org
2018-03-09 14:46   ` srinivas.kandagatla at linaro.org
2018-03-09 14:46   ` srinivas.kandagatla-QSEj5FYQhm4dnm+yROfE0A
2018-03-09 14:46 ` [PATCH 02/25] nvmem: core: Allow specifying device name verbatim srinivas.kandagatla
2018-03-09 14:46   ` srinivas.kandagatla at linaro.org
2018-03-09 14:46   ` srinivas.kandagatla at linaro.org
2018-03-09 14:46   ` srinivas.kandagatla-QSEj5FYQhm4dnm+yROfE0A
2018-03-09 14:46 ` [PATCH 03/25] nvmem: Introduce devm_nvmem_(un)register() srinivas.kandagatla
2018-03-09 14:46   ` srinivas.kandagatla at linaro.org
2018-03-09 14:46   ` srinivas.kandagatla at linaro.org
2018-03-09 14:46   ` srinivas.kandagatla-QSEj5FYQhm4dnm+yROfE0A
2018-03-09 14:46 ` [PATCH 04/25] nvmem: vf610-ocotp: Convert to use devm_nvmem_register() srinivas.kandagatla
2018-03-09 14:46   ` srinivas.kandagatla at linaro.org
2018-03-09 14:46   ` srinivas.kandagatla at linaro.org
2018-03-09 14:46   ` srinivas.kandagatla-QSEj5FYQhm4dnm+yROfE0A
2018-03-09 14:46 ` [PATCH 05/25] nvmem: imx-ocotp: " srinivas.kandagatla
2018-03-09 14:46   ` srinivas.kandagatla at linaro.org
2018-03-09 14:46   ` srinivas.kandagatla at linaro.org
2018-03-09 14:46   ` srinivas.kandagatla
2018-03-09 14:47 ` [PATCH 06/25] nvmem: uniphier-efuse: " srinivas.kandagatla
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47 ` [PATCH 07/25] nvmem: snvs_lgpr: " srinivas.kandagatla
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47 ` [PATCH 08/25] nvmem: rockchip-efuse: " srinivas.kandagatla
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47 ` [PATCH 09/25] nvmem: mtk-efuse: " srinivas.kandagatla
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47 ` [PATCH 10/25] nvmem: meson-mx-efuse: " srinivas.kandagatla
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47 ` [PATCH 11/25] nvmem: meson-efuse: " srinivas.kandagatla
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47 ` [PATCH 12/25] nvmem: lpc18xx_otp: " srinivas.kandagatla
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47 ` [PATCH 13/25] nvmem: imx-iim: " srinivas.kandagatla
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47 ` [PATCH 14/25] nvmem: bcm-ocotp: " srinivas.kandagatla
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47 ` [PATCH 15/25] nvmem: qfprom: " srinivas.kandagatla
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47 ` [PATCH 16/25] nvmem: snvs_lpgpr: Convert commas to semicolons srinivas.kandagatla
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47 ` [PATCH 17/25] nvmem: rockchip-efuse: Make use of of_device_get_match_data() srinivas.kandagatla
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47 ` [PATCH 18/25] nvmem: vf610-ocotp: Do not use "&pdev->dev" explicitly srinivas.kandagatla
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47 ` [PATCH 19/25] nvmem: rockchip-efuse: " srinivas.kandagatla
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47 ` [PATCH 20/25] nvmem: imx-iim: " srinivas.kandagatla
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47 ` [PATCH 21/25] nvmem: bcm-ocotp: " srinivas.kandagatla
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47   ` srinivas.kandagatla at linaro.org
2018-03-09 14:47 ` [PATCH 22/25] nvmem: add i.MX7 support to snvs-lpgpr srinivas.kandagatla
2018-03-09 14:47 ` srinivas.kandagatla [this message]
2018-03-09 14:47 ` [PATCH 24/25] dt-bindings: nvmem: imx-ocotp: update the binding to reflect data cells srinivas.kandagatla
2018-03-09 14:47 ` [PATCH 25/25] nvmem: imx-ocotp: remove unused dead code srinivas.kandagatla

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