nvmem: sunxi-sid: fix H3 SID controller support (0ab09d65) · Commits · 戴 / test

drivers/nvmem/sunxi_sid.c

+50 −21

Original line number	Diff line number	Diff line
		@@ -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;
		}

		@@ -131,25 +174,11 @@ 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;
		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);
		@@ -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);

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