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Message-ID: <4492bd4e-ce32-402c-c52a-a24682f07940@nexus-software.ie>
Date: Wed, 11 Oct 2017 16:54:07 +0100
From: Bryan O'Donoghue <pure.logic@...us-software.ie>
To: Philipp Zabel <p.zabel@...gutronix.de>,
richard.leitner@...data.com, srinivas.kandagatla@...aro.org,
axel.lin@...ics.com, ping.bai@....com, d.schultz@...tec.de,
peng.fan@....com, van.freenix@...il.com
Cc: linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v3 3/7] nvmem: imx-ocotp: Add support for banked OTP
addressing
On 11/10/17 16:32, Philipp Zabel wrote:
> On Mon, 2017-10-09 at 15:11 +0100, Bryan O'Donoghue wrote:
>> The i.MX7S/D takes the bank address in the CTRLn.ADDR field and the data
>> value in one of the DATAx {0, 1, 2, 3} register fields. The current write
>> routine is based on writing the CTRLn.ADDR field and writing a single DATA
>> register only.
>>
>> Fixes: 0642bac7da42 ("nvmem: imx-ocotp: add write support")
>>
>> Signed-off-by: Bryan O'Donoghue <pure.logic@...us-software.ie>
>> ---
>> drivers/nvmem/imx-ocotp.c | 70 +++++++++++++++++++++++++++++++++++++++++------
>> 1 file changed, 61 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/nvmem/imx-ocotp.c b/drivers/nvmem/imx-ocotp.c
>> index 7798571..927d525 100644
>> --- a/drivers/nvmem/imx-ocotp.c
>> +++ b/drivers/nvmem/imx-ocotp.c
>> @@ -40,7 +40,10 @@
>> #define IMX_OCOTP_ADDR_CTRL_SET 0x0004
>> #define IMX_OCOTP_ADDR_CTRL_CLR 0x0008
>> #define IMX_OCOTP_ADDR_TIMING 0x0010
>> -#define IMX_OCOTP_ADDR_DATA 0x0020
>> +#define IMX_OCOTP_ADDR_DATA0 0x0020
>> +#define IMX_OCOTP_ADDR_DATA1 0x0030
>> +#define IMX_OCOTP_ADDR_DATA2 0x0040
>> +#define IMX_OCOTP_ADDR_DATA3 0x0050
>>
>> #define IMX_OCOTP_BM_CTRL_ADDR 0x0000007F
>> #define IMX_OCOTP_BM_CTRL_BUSY 0x00000100
>> @@ -55,6 +58,7 @@ static DEFINE_MUTEX(ocotp_mutex);
>>
>> struct ocotp_params {
>> unsigned int nregs;
>> + unsigned int bank_address_words;
>> };
>>
>> struct ocotp_priv {
>> @@ -176,6 +180,7 @@ static int imx_ocotp_write(void *context, unsigned int offset, void *val,
>> u32 timing = 0;
>> u32 ctrl;
>> u8 waddr;
>> + u8 word = 0;
>>
>> /* allow only writing one complete OTP word at a time */
>> if ((bytes != priv->config->word_size) ||
>> @@ -228,8 +233,22 @@ static int imx_ocotp_write(void *context, unsigned int offset, void *val,
>> * description. Both the unlock code and address can be written in the
>> * same operation.
>> */
>> - /* OTP write/read address specifies one of 128 word address locations */
>> - waddr = offset / 4;
>> + if (priv->params->bank_address_words != 0) {
>> + /*
>> + * In banked mode the OTP register bank goes into waddr see
>> + * i.MX 7Solo Applications Processor Reference Manual, Rev. 0.1
>> + * 6.4.3.1
>> + */
>> + offset = offset / priv->config->word_size;
>> + waddr = offset / priv->params->bank_address_words;
>> + word = offset & (priv->params->bank_address_words - 1);
>> + } else {
>> + /*
>> + * OTP write/read address specifies one of 128 word address
>> + * locations
>> + */
>> + waddr = offset / 4;
>> + }
>
> Smallest of nitpicks, here the order is:
>
> if (bank_address_words != 0) {
> /* MX7 */
> } else {
> /* MX6 */
> }
>
>>
>> ctrl = readl(priv->base + IMX_OCOTP_ADDR_CTRL);
>> ctrl &= ~IMX_OCOTP_BM_CTRL_ADDR;
>> @@ -255,8 +274,41 @@ static int imx_ocotp_write(void *context, unsigned int offset, void *val,
>> * shift right (with zero fill). This shifting is required to program
>> * the OTP serially. During the write operation, HW_OCOTP_DATA cannot be
>> * modified.
>> + * Note: on i.MX7 there are four data fields to write for banked write
>> + * with the fuse blowing operation only taking place after data0
>> + * has been written. This is why data0 must always be the last
>> + * register written.
>> */
>> - writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA);
>> + if (priv->params->bank_address_words == 0) {
>> + writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA0);
>> + } else {
>> + switch (word) {
>> + case 0:
>> + writel(0, priv->base + IMX_OCOTP_ADDR_DATA1);
>> + writel(0, priv->base + IMX_OCOTP_ADDR_DATA2);
>> + writel(0, priv->base + IMX_OCOTP_ADDR_DATA3);
>> + writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA0);
>> + break;
>> + case 1:
>> + writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA1);
>> + writel(0, priv->base + IMX_OCOTP_ADDR_DATA2);
>> + writel(0, priv->base + IMX_OCOTP_ADDR_DATA3);
>> + writel(0, priv->base + IMX_OCOTP_ADDR_DATA0);
>> + break;
>> + case 2:
>> + writel(0, priv->base + IMX_OCOTP_ADDR_DATA1);
>> + writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA2);
>> + writel(0, priv->base + IMX_OCOTP_ADDR_DATA3);
>> + writel(0, priv->base + IMX_OCOTP_ADDR_DATA0);
>> + break;
>> + case 3:
>> + writel(0, priv->base + IMX_OCOTP_ADDR_DATA1);
>> + writel(0, priv->base + IMX_OCOTP_ADDR_DATA2);
>> + writel(*buf, priv->base + IMX_OCOTP_ADDR_DATA3);
>> + writel(0, priv->base + IMX_OCOTP_ADDR_DATA0);
>> + break;
>> + }
>> + }
>
> But here the order is
> if (bank_address_words == 0) {
> /* MX6 */
> } else {
> /* MX7 */
> }
>
> Reordering this for consistency would also move the MX7 code closer to
> the comment.
>
>>
>> /* 47.4.1.4.5
>> * Once complete, the controller will clear BUSY. A write request to a
>> @@ -313,11 +365,11 @@ static struct nvmem_config imx_ocotp_nvmem_config = {
>> };
>>
>> static const struct ocotp_params params[] = {
>> - { .nregs = 128 },
>> - { .nregs = 64 },
>> - { .nregs = 128 },
>> - { .nregs = 128 },
>> - { .nregs = 64 },
>> + { .nregs = 128, .bank_address_words = 0 },
>> + { .nregs = 64, .bank_address_words = 0 },
>> + { .nregs = 128, .bank_address_words = 0 },
>> + { .nregs = 128, .bank_address_words = 0 },
>> + { .nregs = 64, .bank_address_words = 4 },
>
> See my comment on the last patch, I'd like to be able see which entry
> corresponds to which SoC in this patch.
>
> Otherwise,
>
> Reviewed-by: Philipp Zabel <p.zabel@...gutronix.de>
>
> regards
> Philipp
>
ACK those changes Philipp.
Thanks for your suggestions/time
---
bod
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