From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: ARC-Seal: i=1; a=rsa-sha256; t=1520607054; cv=none; d=google.com; s=arc-20160816; b=fDet7WVtpDnWC6Fp0j9sm+cp70Rag4VfbmHxuQzkjJ5doMtOy4l3KT8Qq9nQTyOU5D 2IP7/jE1WNxXQaYd5U8283y0JiAK3HZ3J04kxkrFozli4XPHyDn/2NA87JysHkNPKUFG uHDA+QlVqc2i36Gz1dCxXe++IffcZKon5bAFm3FPsWTf9kG9htbRDOoBTpE9/sUl4Qv8 ixNMjwXcjFOFFUmlYrKG3jNBvNrRCtoGXFzhPW/71BMsxEzPD5wJuNTyvPLjLcqOo1Hh l0Fxiva80bn1ZJgETKMrCFGajNutSlZqnUj6PDKJbmhhrLRq2k9SLvM4SvQPtHQsFsYP eZHQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature:arc-authentication-results; bh=Ufwf7qBywoUhGsTDixw/ddKEjV907Zte7g3Yg4PGjmw=; b=BGXq01r6gi6HrqgHT0/KuwixNQ1+4lzhkXdj+157MaQ4BMVKDCxZTtWop+9Usb24X7 W7Z/v1hhHuJQt9jhq+Lwt2eqC3X9KvSb1KFUxSpKKL+VfDCvA+CEQ+yBVTExRwLHLP5j li6SOuV1fFUXva9eZ35vv/JNDHLfYvar3YqdXzk9qHGckTbDpgcq6e4JcXtD8zP6KDFZ y09OWF7fwK5MmwYF40mZ1fID7dpjf43xlTzceq6qMq9MjV+ncSK4pDb9SAVv5awKl6lp XBouFhBn+O/wDOUuTkkhXUSmwVTRa1/XOA7ckHMr5M8JihXlXC9XzLds/Kz1M5gLOSWM 9G1w== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=HjvFaFKH; spf=pass (google.com: domain of srinivas.kandagatla@linaro.org designates 209.85.220.65 as permitted sender) smtp.mailfrom=srinivas.kandagatla@linaro.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=HjvFaFKH; spf=pass (google.com: domain of srinivas.kandagatla@linaro.org designates 209.85.220.65 as permitted sender) smtp.mailfrom=srinivas.kandagatla@linaro.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org X-Google-Smtp-Source: AG47ELvkSt0a+ekdCBRHX9Oko4MwOWN4Wlrz5ZGnUXupe0YB7J96eji8c1dax5U50USssWLfxRjjwg== From: srinivas.kandagatla@linaro.org To: gregkh@linuxfoundation.org Cc: linux-kernel@vger.kernel.org, srinivas.kandagatla@linaro.org, Icenowy Zheng Subject: [PATCH 23/25] nvmem: sunxi-sid: fix H3 SID controller support Date: Fri, 9 Mar 2018 14:47:17 +0000 Message-Id: <20180309144719.29904-24-srinivas.kandagatla@linaro.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180309144719.29904-1-srinivas.kandagatla@linaro.org> References: <20180309144719.29904-1-srinivas.kandagatla@linaro.org> X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1594472062130495903?= X-GMAIL-MSGID: =?utf-8?q?1594472062130495903?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: From: Icenowy Zheng 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 Signed-off-by: Srinivas Kandagatla --- 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