Hi, On Thu, Dec 03, 2015 at 03:05:30PM +0800, Chen-Yu Tsai wrote: > The APBS clock on sun9i is the same as the APB0 clock on sun8i. With > sun9i we are supporting the PRCM clocks by using CLK_OF_DECLARE, > instead of through a PRCM mfd device and subdevices for each clock > and reset control. As such we need a CLK_OF_DECLARE version of > the sun8i-a23-apb0-clk driver. > > Also, build it for sun9i/A80, and not just for configurations with > MFD_SUN6I_PRCM enabled. > > Signed-off-by: Chen-Yu Tsai <w...@csie.org> > --- > > Changes since v4: > > - Keep building clk-sun8i-apb0 for SUN6I_MFD_PRCM. > > - Add an error message and comment for when of_io_request_and_map() > fails. of_io_request_and_map() merges a bunch of errors into -EINVAL, > so this might not be the best approach. But I think having an error > message when we know something is wrong (-EBUSY, -ENOMEM) is better. > > --- > drivers/clk/sunxi/Makefile | 1 + > drivers/clk/sunxi/clk-sun8i-apb0.c | 80 > ++++++++++++++++++++++++++++++++------ > 2 files changed, 69 insertions(+), 12 deletions(-) > > diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile > index 103efab05ca8..ccf21ba3b6b0 100644 > --- a/drivers/clk/sunxi/Makefile > +++ b/drivers/clk/sunxi/Makefile > @@ -15,6 +15,7 @@ obj-y += clk-sun9i-core.o > obj-y += clk-sun9i-mmc.o > obj-y += clk-usb.o > > +obj-$(CONFIG_MACH_SUN9I) += clk-sun8i-apb0.o > obj-$(CONFIG_MACH_SUN9I) += clk-sun9i-cpus.o > > obj-$(CONFIG_MFD_SUN6I_PRCM) += \ > diff --git a/drivers/clk/sunxi/clk-sun8i-apb0.c > b/drivers/clk/sunxi/clk-sun8i-apb0.c > index 7ae5d2c2cde1..7ba61103a6f5 100644 > --- a/drivers/clk/sunxi/clk-sun8i-apb0.c > +++ b/drivers/clk/sunxi/clk-sun8i-apb0.c > @@ -17,13 +17,77 @@ > #include <linux/clk-provider.h> > #include <linux/module.h> > #include <linux/of.h> > +#include <linux/of_address.h> > #include <linux/platform_device.h> > > +static struct clk *sun8i_a23_apb0_register(struct device_node *node, > + void __iomem *reg) > +{ > + const char *clk_name = node->name; > + const char *clk_parent; > + struct clk *clk; > + int ret; > + > + clk_parent = of_clk_get_parent_name(node, 0); > + if (!clk_parent) > + return ERR_PTR(-EINVAL); > + > + of_property_read_string(node, "clock-output-names", &clk_name); > + > + /* The A23 APB0 clock is a standard 2 bit wide divider clock */ > + clk = clk_register_divider(NULL, clk_name, clk_parent, 0, reg, > + 0, 2, CLK_DIVIDER_POWER_OF_TWO, NULL); > + if (IS_ERR(clk)) > + return clk; > + > + ret = of_clk_add_provider(node, of_clk_src_simple_get, clk); > + if (ret) > + goto err_unregister; > + > + return clk; > + > +err_unregister: > + clk_unregister_divider(clk); > + > + return ERR_PTR(ret); > +} > + > +static void sun8i_a23_apb0_setup(struct device_node *node) > +{ > + void __iomem *reg; > + struct resource res; > + struct clk *clk; > + > + reg = of_io_request_and_map(node, 0, of_node_full_name(node)); > + if (IS_ERR(reg)) { > + /* > + * This happens with clk nodes instantiated through mfd, > + * as those do not have their resources assigned in the > + * device tree. Do not print an error in this case. > + */ > + if (PTR_ERR(reg) != -EINVAL) > + pr_err("Could not get registers for a23-apb0-clk\n");
This is not the only case you have to take into account. There's also the case when you have a regular clock (and by regular I mean that is not in the PRCM) that will be probed by the CLK_OF_DECLARE mechanism and then later by the device model. In such a case, the second of_io_request_and_map will fail, and you will have an error returned that you do not ignore at the moment. Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com
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