From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
To: Cosmin Tanislav <demonsingur@gmail.com>
Cc: "Nuno Sá" <nuno.sa@analog.com>,
"Lars-Peter Clausen" <lars@metafoo.de>,
"Michael Hennerich" <Michael.Hennerich@analog.com>,
"Jonathan Cameron" <jic23@kernel.org>,
"Rob Herring" <robh+dt@kernel.org>,
"Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
linux-iio@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org,
"Cosmin Tanislav" <cosmin.tanislav@analog.com>
Subject: Re: [PATCH 3/3] iio: temperature: ltc2983: support more parts
Date: Fri, 14 Oct 2022 16:44:41 +0100 [thread overview]
Message-ID: <20221014164435.000016a1@huawei.com> (raw)
In-Reply-To: <20221014123724.1401011-4-demonsingur@gmail.com>
On Fri, 14 Oct 2022 15:37:24 +0300
Cosmin Tanislav <demonsingur@gmail.com> wrote:
> From: Cosmin Tanislav <cosmin.tanislav@analog.com>
>
> Add support for the following parts:
> * LTC2984
> * LTC2986
> * LTM2985
>
> The LTC2984 is a variant of the LTC2983 with EEPROM.
> The LTC2986 is a variant of the LTC2983 with only 10 channels,
> EEPROM and support for active analog temperature sensors.
> The LTM2985 is software-compatible with the LTC2986.
>
> Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
...
Hi Cosmin,
Looks good except, I think we are still in the position that
regmap for spi doesn't guarantee to bounce buffer the bulk accesses
(last time I checked it actually did do so, but before that it didn't
and there are obvious optimizations to take it back to not doing so -
IRC Mark Brown's answer was we shouldn't rely on it..)
Anyhow, the existing driver has instances of this so its no worse
but we should really clean those up.
Jonathan
>
> +static int ltc2983_eeprom_cmd(struct ltc2983_data *st, unsigned int cmd,
> + unsigned int wait_time, unsigned int status_reg,
> + unsigned long status_fail_mask)
> +{
> + __be32 bval = cpu_to_be32(LTC2983_EEPROM_KEY);
> + unsigned long time;
> + unsigned int val;
> + int ret;
> +
> + ret = regmap_bulk_write(st->regmap, LTC2983_EEPROM_KEY_REG, &bval,
> + sizeof(bval));
SPI device and I was clearly dozing on existing driver but normally
we avoid assuming that regmap will always use a bounce buffer for bulk
accessors. Hence this should be a DMA safe buffer.
> + if (ret)
> + return ret;
> +
> + reinit_completion(&st->completion);
> +
> + ret = regmap_write(st->regmap, LTC2983_STATUS_REG,
> + LTC2983_STATUS_START(true) | cmd);
> + if (ret)
> + return ret;
> +
> + time = wait_for_completion_timeout(&st->completion,
> + msecs_to_jiffies(wait_time));
> + if (!time) {
> + dev_err(&st->spi->dev, "EEPROM command timed out\n");
> + return -ETIMEDOUT;
> + }
> +
> + ret = regmap_read(st->regmap, status_reg, &val);
> + if (ret)
> + return ret;
> +
> + if (val & status_fail_mask) {
> + dev_err(&st->spi->dev, "EEPROM command failed: 0x%02X\n", val);
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
next prev parent reply other threads:[~2022-10-14 15:45 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-14 12:37 [PATCH 0/3] Support more parts in LTC2983 Cosmin Tanislav
2022-10-14 12:37 ` [PATCH 1/3] iio: temperature: ltc2983: allocate iio channels once Cosmin Tanislav
2022-10-14 14:11 ` Jonathan Cameron
2022-10-14 15:18 ` Jonathan Cameron
2022-10-15 16:35 ` Jonathan Cameron
2022-10-14 12:37 ` [PATCH 2/3] dt-bindings: iio: temperature: ltc2983: support more parts Cosmin Tanislav
2022-10-14 15:37 ` Jonathan Cameron
2022-10-17 7:01 ` Cosmin Tanislav
2022-10-17 10:22 ` Jonathan Cameron
2022-10-17 1:59 ` Krzysztof Kozlowski
2022-10-17 6:53 ` Cosmin Tanislav
2022-10-17 10:26 ` Jonathan Cameron
2022-10-17 10:37 ` Jonathan Cameron
2022-10-17 23:26 ` Krzysztof Kozlowski
2022-10-17 9:38 ` Nuno Sá
2022-10-17 10:04 ` Nuno Sá
2022-10-17 23:32 ` Krzysztof Kozlowski
2022-10-18 6:01 ` Nuno Sá
2022-10-14 12:37 ` [PATCH 3/3] " Cosmin Tanislav
2022-10-14 15:44 ` Jonathan Cameron [this message]
2022-10-17 6:59 ` Cosmin Tanislav
2022-10-17 10:29 ` Jonathan Cameron
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