From: Sascha Hauer <s.hauer@pengutronix.de>
To: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: barebox@lists.infradead.org
Subject: Re: [PATCH] i2c: Add support for DesignWare controllers
Date: Mon, 2 Nov 2015 09:30:07 +0100 [thread overview]
Message-ID: <20151102083007.GC17132@pengutronix.de> (raw)
In-Reply-To: <1446352242-8053-1-git-send-email-andrew.smirnov@gmail.com>
On Sat, Oct 31, 2015 at 09:30:41PM -0700, Andrey Smirnov wrote:
> Add a driver for DesignWare I2C controller IP block found on several
> SoCs including Altera SoC products
>
> Tested using Terrasic SoCKit board and GPIO expander board with I2C
> EEPROM on it
>
> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
> ---
Looks mostly fine. Two small nitpicks inside.
> +static int i2c_dw_probe(struct device_d *pdev)
> +{
> + struct dw_i2c_dev *dw;
> + struct i2c_platform_data *pdata;
> + int ret, bitrate;
> + uint32_t ic_con, ic_comp_type_value;
> +
> + pdata = pdev->platform_data;
> +
> + dw = kzalloc(sizeof(*dw), GFP_KERNEL);
kzalloc can fail. You should use xzalloc here which cannot fail.
> +
> + if (IS_ENABLED(CONFIG_COMMON_CLK)) {
> + dw->clk = clk_get(pdev, NULL);
> + if (IS_ERR(dw->clk)) {
> + ret = PTR_ERR(dw->clk);
> + goto fail;
> + }
> + }
> +
> + dw->adapter.master_xfer = i2c_dw_xfer;
> + dw->adapter.nr = pdev->id;
> + dw->adapter.dev.parent = pdev;
> + dw->adapter.dev.device_node = pdev->device_node;
> +
> + dw->base = dev_request_mem_region(pdev, 0);
> + if (IS_ERR(dw->base)) {
> + ret = PTR_ERR(dw->base);
> + goto fail;
> + }
> +
> + ic_comp_type_value = readl(dw->base + DW_IC_COMP_TYPE);
> + if (ic_comp_type_value != DW_IC_COMP_TYPE_VALUE) {
> + dev_err(pdev,
> + "unknown DesignWare IP block 0x%08x",
> + ic_comp_type_value);
> + ret = -ENODEV;
> + goto fail;
> + }
> +
> + i2c_dw_enable(dw, false);
> +
> + if (IS_ENABLED(CONFIG_COMMON_CLK))
> + i2c_dw_setup_timings(dw);
> +
> + bitrate = (pdata && pdata->bitrate) ? pdata->bitrate : DW_I2C_BIT_RATE;
> +
> + /*
> + * We have to clear 'ic_10bitaddr_master' in 'ic_tar'
> + * register, otherwise 'ic_10bitaddr_master' in 'ic_con'
> + * wouldn't clear. We don't care about preserving the contents
> + * of that register so we set it to zero.
> + */
> + writel(0, dw->base + DW_IC_TAR);
> +
> + switch (bitrate) {
> + case 400000:
> + ic_con = DW_IC_CON_SPEED_FAST;
> + break;
> + default:
> + dev_warn(pdev, "requested bitrate (%d) is not supported."
> + " Falling back to 100kHz", bitrate);
> + case 100000: /* FALLTHROUGH */
> + ic_con = DW_IC_CON_SPEED_STD;
> + break;
> + }
> +
> + ic_con |= DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE;
> +
> + writel(ic_con, dw->base + DW_IC_CON);
> +
> + /*
> + * Since we will be working in polling mode set both
> + * thresholds to their minimum
> + */
> + writel(0, dw->base + DW_IC_RX_TL);
> + writel(0, dw->base + DW_IC_TX_TL);
> +
> + /* Disable and clear all interrrupts */
> + writel(0, dw->base + DW_IC_INTR_MASK);
> + readl(dw->base + DW_IC_CLR_INTR);
> +
> + i2c_dw_enable(dw, true);
> +
> + ret = i2c_add_numbered_adapter(&dw->adapter);
> +fail:
> + if (ret < 0) {
> + dev_err(pdev, "registration failed\n");
This message is unnecessary. The driver core will warn you when probe
fails anyway.
Sascha
--
Pengutronix e.K. | |
Industrial Linux Solutions | http://www.pengutronix.de/ |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox
prev parent reply other threads:[~2015-11-02 8:30 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-01 4:30 Andrey Smirnov
2015-11-01 4:30 ` [PATCH] memtest: Fix reference to non-existing function Andrey Smirnov
2015-11-02 8:30 ` Sascha Hauer [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20151102083007.GC17132@pengutronix.de \
--to=s.hauer@pengutronix.de \
--cc=andrew.smirnov@gmail.com \
--cc=barebox@lists.infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox