From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Prisk Subject: Re: [PATCH 2/3] PWM: vt8500: Update vt8500 PWM driver support Date: Mon, 22 Oct 2012 20:09:07 +1300 Message-ID: <1350889747.3592.17.camel@gitbox> References: <1350643135-13197-1-git-send-email-linux@prisktech.co.nz> <1350643135-13197-2-git-send-email-linux@prisktech.co.nz> <20121022063423.GA17181@avionic-0098.mockup.avionic-design.de> <1350888712.3592.11.camel@gitbox> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1350888712.3592.11.camel@gitbox> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Thierry Reding Cc: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, arm-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org On Mon, 2012-10-22 at 19:51 +1300, Tony Prisk wrote: > > > > > chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL); > > > if (chip == NULL) { > > > dev_err(&pdev->dev, "failed to allocate memory\n"); > > > @@ -123,26 +144,32 @@ static int __devinit pwm_probe(struct platform_device *pdev) > > > chip->chip.ops = &vt8500_pwm_ops; > > > chip->chip.base = -1; > > > chip->chip.npwm = VT8500_NR_PWMS; > > > + chip->clk = of_clk_get(np, 0); > > > > I thought this was supposed to work transparently across OF and !OF > > configurations by using just clk_get() or devm_clk_get()? I guess that > > if the driver depends on OF, then this would be moot, but we should > > probably stick to the standard usage anyway. > > > > Furthermore, of_clk_get() doesn't seem to be managed, so you'd need to > > add explicit clk_put() in the error cleanup paths. One more argument in > > favour of using devm_clk_get() instead. > > Hmm good point. I stuck with of_ functions because its an OF only driver > and it seemed 'backward' to mix old code with new. It does pose the > question of 'why have of_clk_get() if existing functions work better'. Was about to fix this but noticed why it wasn't like this to start with :) struct clk *devm_clk_get(struct device *dev, const char *id); struct clk *of_clk_get(struct device_node *np, int index); devm_clk_get requires me to 'get' the clock by name. arch-vt8500 (and I believe a lot of other arch's) don't enforce names for clocks defined in devicetree, therefore there is no way for me to know what name the clk has unless I include in the binding that the clock must be named 'xxx'. of_clk_get retrieves it by the dt-node + index, so it doesn't care as long as its the 1st clock listed. Welcome your feedback. Regards Tony P