From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vladimir Zapolskiy Subject: Re: [PATCH v3 1/2] i2c: Add Imagination Technologies I2C SCB driver Date: Thu, 6 Nov 2014 18:51:05 +0200 Message-ID: <545BA6F9.3090207@mentor.com> References: <1415218919-9085-1-git-send-email-ezequiel.garcia@imgtec.com> <1415218919-9085-2-git-send-email-ezequiel.garcia@imgtec.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1415218919-9085-2-git-send-email-ezequiel.garcia-1AXoQHu6uovQT0dZR+AlfA@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ezequiel Garcia , James Hogan Cc: Wolfram Sang , James Hartley , Andrew Bresticker , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org Hi Ezequiel, On 05.11.2014 22:21, Ezequiel Garcia wrote: > From: James Hogan > > Add support for the IMG I2C Serial Control Bus (SCB) found on the > Pistachio and TZ1090 SoCs. > > Signed-off-by: James Hogan > [Ezequiel: code cleaning and rebasing] > Signed-off-by: Ezequiel Garcia > --- > drivers/i2c/busses/Kconfig | 10 + > drivers/i2c/busses/Makefile | 1 + > drivers/i2c/busses/i2c-img-scb.c | 1397 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 1408 insertions(+) > create mode 100644 drivers/i2c/busses/i2c-img-scb.c > [snip] > +static int img_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, > + int num) > +{ > + struct img_i2c *i2c = i2c_get_adapdata(i2c_adap); > + bool atomic = false; > + int i; > + > + if (i2c->mode == MODE_SUSPEND) { > + WARN(1, "refusing to service transaction in suspended state\n"); > + return -EIO; > + } > + > + if (i2c->mode == MODE_FATAL) > + return -EIO; > + > + for (i = 0; i < num; i++) { > + if (likely(msgs[i].len)) > + continue; > + /* > + * 0 byte reads are not possible because the slave could try > + * and pull the data line low, preventing a stop bit. > + */ > + if (unlikely(msgs[i].flags & I2C_M_RD)) > + return -EIO; > + /* > + * 0 byte writes are possible and used for probing, but we > + * cannot do them in automatic mode, so use atomic mode > + * instead. > + */ > + atomic = true; > + } > + > + clk_prepare_enable(i2c->scb_clk); Does it make sense to add a check for returned error here? > + for (i = 0; i < num; i++) { > + struct i2c_msg *msg = &msgs[i]; > + unsigned long flags; > + > + spin_lock_irqsave(&i2c->lock, flags); > + > + /* > + * Make a copy of the message struct. We mustn't modify the > + * original or we'll confuse drivers and i2c-dev. > + */ > + i2c->msg = *msg; > + i2c->msg_status = 0; > + > + /* [snip] > + > +static int img_i2c_resume(struct device *dev) > +{ > + struct img_i2c *i2c = dev_get_drvdata(dev); > + > + clk_enable(i2c->sys_clk); Same question as above. > + img_i2c_init(i2c); > + > + return 0; > +} > +#endif /* CONFIG_PM_SLEEP */ > + > +static SIMPLE_DEV_PM_OPS(img_i2c_pm, img_i2c_suspend, img_i2c_resume); > + > +static const struct of_device_id img_scb_i2c_match[] = { > + { .compatible = "img,scb-i2c" }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, img_scb_i2c_match); > + > +static struct platform_driver img_scb_i2c_driver = { > + .driver = { > + .name = "img-i2c-scb", > + .of_match_table = img_scb_i2c_match, > + .pm = &img_i2c_pm, > + }, > + .probe = img_i2c_probe, > + .remove = img_i2c_remove, > +}; > +module_platform_driver(img_scb_i2c_driver); > + > +MODULE_AUTHOR("James Hogan "); > +MODULE_DESCRIPTION("IMG host I2C driver"); > +MODULE_LICENSE("GPL"); > -- With best wishes, Vladimir