On Thu, Nov 19, 2015 at 07:35:58PM +0100, Geert Uytterhoeven wrote: > From: Laurent Pinchart <[email protected]> > > As no platform defines an interface clock the SCI driver always falls > back to a clock named "peripheral_clk". > - On SH platforms that clock is the base clock for the SCI functional > clock and has the same frequency, > - On ARM platforms that clock doesn't exist, and clk_get() will return > the default clock for the device. > We can thus make the functional clock mandatory and drop the interface > clock. > > EPROBE_DEFER is handled for clocks that may be referenced from DT (i.e. > "fck" and deprecated "sci_ick"). > > Cc: [email protected] > Signed-off-by: Laurent Pinchart <[email protected]> > Acked-by: Simon Horman <[email protected]> > [geert: Handle EPROBE_DEFER, reformat description, break long comment line] > Signed-off-by: Geert Uytterhoeven <[email protected]>
This could break users that care about the clock name. A new dtb with old kernel would be one example. I guess you are okay with that, so: Acked-by: Rob Herring <[email protected]> > --- > v2: > - Add Acked-by, > - Amendment by geert. > --- > .../bindings/serial/renesas,sci-serial.txt | 4 +- > drivers/tty/serial/sh-sci.c | 64 > ++++++++++++++-------- > 2 files changed, 43 insertions(+), 25 deletions(-) > > diff --git a/Documentation/devicetree/bindings/serial/renesas,sci-serial.txt > b/Documentation/devicetree/bindings/serial/renesas,sci-serial.txt > index 73f825e5e6448815..2c9e6b8477e92792 100644 > --- a/Documentation/devicetree/bindings/serial/renesas,sci-serial.txt > +++ b/Documentation/devicetree/bindings/serial/renesas,sci-serial.txt > @@ -42,7 +42,7 @@ Required properties: > > - clocks: Must contain a phandle and clock-specifier pair for each entry > in clock-names. > - - clock-names: Must contain "sci_ick" for the SCIx UART interface clock. > + - clock-names: Must contain "fck" for the SCIx UART functional clock. > > Note: Each enabled SCIx UART should have an alias correctly numbered in the > "aliases" node. > @@ -63,7 +63,7 @@ Example: > interrupt-parent = <&gic>; > interrupts = <0 144 IRQ_TYPE_LEVEL_HIGH>; > clocks = <&mstp2_clks R8A7790_CLK_SCIFA0>; > - clock-names = "sci_ick"; > + clock-names = "fck"; > dmas = <&dmac0 0x21>, <&dmac0 0x22>; > dma-names = "tx", "rx"; > }; > diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c > index 51c7507b0444957b..3c908804cab1c88c 100644 > --- a/drivers/tty/serial/sh-sci.c > +++ b/drivers/tty/serial/sh-sci.c > @@ -92,8 +92,6 @@ struct sci_port { > struct timer_list break_timer; > int break_flag; > > - /* Interface clock */ > - struct clk *iclk; > /* Function clock */ > struct clk *fclk; > > @@ -457,9 +455,8 @@ static void sci_port_enable(struct sci_port *sci_port) > > pm_runtime_get_sync(sci_port->port.dev); > > - clk_prepare_enable(sci_port->iclk); > - sci_port->port.uartclk = clk_get_rate(sci_port->iclk); > clk_prepare_enable(sci_port->fclk); > + sci_port->port.uartclk = clk_get_rate(sci_port->fclk); > } > > static void sci_port_disable(struct sci_port *sci_port) > @@ -476,7 +473,6 @@ static void sci_port_disable(struct sci_port *sci_port) > sci_port->break_flag = 0; > > clk_disable_unprepare(sci_port->fclk); > - clk_disable_unprepare(sci_port->iclk); > > pm_runtime_put_sync(sci_port->port.dev); > } > @@ -1622,7 +1618,7 @@ static int sci_notifier(struct notifier_block *self, > struct uart_port *port = &sci_port->port; > > spin_lock_irqsave(&port->lock, flags); > - port->uartclk = clk_get_rate(sci_port->iclk); > + port->uartclk = clk_get_rate(sci_port->fclk); > spin_unlock_irqrestore(&port->lock, flags); > } > > @@ -2241,6 +2237,42 @@ static struct uart_ops sci_uart_ops = { > #endif > }; > > +static int sci_init_clocks(struct sci_port *sci_port, struct device *dev) > +{ > + /* Get the SCI functional clock. It's called "fck" on ARM. */ > + sci_port->fclk = clk_get(dev, "fck"); > + if (PTR_ERR(sci_port->fclk) == -EPROBE_DEFER) > + return -EPROBE_DEFER; > + if (!IS_ERR(sci_port->fclk)) > + return 0; > + > + /* > + * But it used to be called "sci_ick", and we need to maintain DT > + * backward compatibility. > + */ > + sci_port->fclk = clk_get(dev, "sci_ick"); > + if (PTR_ERR(sci_port->fclk) == -EPROBE_DEFER) > + return -EPROBE_DEFER; > + if (!IS_ERR(sci_port->fclk)) > + return 0; > + > + /* SH has historically named the clock "sci_fck". */ > + sci_port->fclk = clk_get(dev, "sci_fck"); > + if (!IS_ERR(sci_port->fclk)) > + return 0; > + > + /* > + * Not all SH platforms declare a clock lookup entry for SCI devices, > + * in which case we need to get the global "peripheral_clk" clock. > + */ > + sci_port->fclk = clk_get(dev, "peripheral_clk"); > + if (!IS_ERR(sci_port->fclk)) > + return 0; > + > + dev_err(dev, "failed to get functional clock\n"); > + return PTR_ERR(sci_port->fclk); > +} > + > static int sci_init_single(struct platform_device *dev, > struct sci_port *sci_port, unsigned int index, > struct plat_sci_port *p, bool early) > @@ -2333,22 +2365,9 @@ static int sci_init_single(struct platform_device *dev, > sci_port->sampling_rate = p->sampling_rate; > > if (!early) { > - sci_port->iclk = clk_get(&dev->dev, "sci_ick"); > - if (IS_ERR(sci_port->iclk)) { > - sci_port->iclk = clk_get(&dev->dev, "peripheral_clk"); > - if (IS_ERR(sci_port->iclk)) { > - dev_err(&dev->dev, "can't get iclk\n"); > - return PTR_ERR(sci_port->iclk); > - } > - } > - > - /* > - * The function clock is optional, ignore it if we can't > - * find it. > - */ > - sci_port->fclk = clk_get(&dev->dev, "sci_fck"); > - if (IS_ERR(sci_port->fclk)) > - sci_port->fclk = NULL; > + ret = sci_init_clocks(sci_port, &dev->dev); > + if (ret < 0) > + return ret; > > port->dev = &dev->dev; > > @@ -2405,7 +2424,6 @@ static int sci_init_single(struct platform_device *dev, > > static void sci_cleanup_single(struct sci_port *port) > { > - clk_put(port->iclk); > clk_put(port->fclk); > > pm_runtime_disable(port->port.dev); > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe devicetree" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
