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Subject: Re: [PATCH v6 2/2] spi: cadence-quadpsi: Add support for the Cadence
 QSPI controller
To:     "Ramuthevar,Vadivel MuruganX" 
        <vadivel.muruganx.ramuthevar@linux.intel.com>,
        <broonie@kernel.org>, <linux-spi@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
CC:     <robh+dt@kernel.org>, <dan.carpenter@oracle.com>,
        <cheol.yong.kim@intel.com>, <qi-ming.wu@intel.com>
References: <20191230074102.50982-1-vadivel.muruganx.ramuthevar@linux.intel.com>
 <20191230074102.50982-3-vadivel.muruganx.ramuthevar@linux.intel.com>
From:   Vignesh Raghavendra <vigneshr@ti.com>
Message-ID: <e89cf037-217b-cd61-79ee-a11e2a118c01@ti.com>
Date:   Mon, 6 Jan 2020 16:10:39 +0530
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Hi,

On 30/12/19 1:11 pm, Ramuthevar,Vadivel MuruganX wrote:
[...]
> +static u32 cqspi_cmd2addr(const unsigned char *addr_buf, u32 addr_width)
> +{
> +	unsigned int addr = 0;
> +	int i;
> +
> +	/* Invalid address return zero. */
> +	if (addr_width > 4)
> +		return 0;
> +
> +	for (i = 0; i < addr_width; i++) {
> +		addr = addr << 8;
> +		addr |= addr_buf[i];
> +	}
> +
> +	return addr;
> +}
> +
[...]
> +static int cqspi_apb_read_setup(struct struct_cqspi *cqspi,
> +				const struct spi_mem_op *op,
> +				const u8 *addrbuf)
> +{
> +	void __iomem *reg_base = cqspi->iobase;
> +	size_t addrlen = op->addr.nbytes;
> +	size_t dummy_bytes = op->dummy.nbytes;
> +	unsigned int addr_value, dummy_clk, reg;
> +
> +	if (addrlen) {
> +		addr_value = cqspi_cmd2addr(&addrbuf[0], addrlen);
> +		writel(addr_value, reg_base + CQSPI_REG_INDIRECTRDSTARTADDR);
> +	}
> +

Why do you need to swap the address bytes to SPI bus order? You are
writing to a controller register that accepts 24 bit or 32 bit address.

> +	reg = op->cmd.opcode << CQSPI_REG_RD_INSTR_OPCODE_LSB;
> +	reg |= (op->data.buswidth & CQSPI_REG_RD_INSTR_TYPE_DATA_MASK) <<
> +		CQSPI_REG_RD_INSTR_TYPE_DATA_LSB;
> +

This is wrong... op->data.buswidth's range is 1 to 8 whereas
CQSPI_REG_RD_INSTR_TYPE range is 0 to 3. I wonder whether you tested
dual/quad mode with this driver?

I am still unable to get this series to work on my platform. Will
continue to debug...

-- 
Regards
Vignesh