Re: [PATCH 4/6] ARM: bcm476x: Add stub clock driver

On 10/06/2012 07:53 PM, Domenico Andreoli wrote:

From: Domenico Andreoli <redacted>

This is the minimal clock support required for the boot, a more complete
implementation will follow (shortly).

Index: b/drivers/clk/clk-bcm476x.c

+/*
+ * These are fixed clocks (and device tree doesn't support clk!).
+ *
+ * They're probably not all root clocks and it may be possible to
+ * turn them on and off but until this is mapped out better it's
+ * the only way they can be used.
+ */
+DEFINE_CLK_FIXED_RATE(sys_pclk,   CLK_IS_ROOT, 312000000, 0);
+DEFINE_CLK_FIXED_RATE(apb_pclk,   CLK_IS_ROOT, 156000000, 0);
+DEFINE_CLK_FIXED_RATE(uart0_pclk, CLK_IS_ROOT, 78000000, 0);
+DEFINE_CLK_FIXED_RATE(uart1_pclk, CLK_IS_ROOT, 78000000, 0);
+DEFINE_CLK_FIXED_RATE(uart2_pclk, CLK_IS_ROOT, 78000000, 0);
+
+static struct clk_lookup lookups[] = {
+	{ .con_id = "sys_pclk", .clk = &sys_pclk },
+	{ .con_id = "apb_pclk", .clk = &apb_pclk },
+	{ .dev_id = "c0000.uart0", .clk = &uart0_pclk },
+	{ .dev_id = "c1000.uart1", .clk = &uart1_pclk },
+	{ .dev_id = "b2000.uart2", .clk = &uart2_pclk },
+};

Mike Turquette (common clk maintainer) objected to this form of static
clock initialization when I originally posted the bcm2835 patches.
Instead, please see how it got re-written dynamically:

https://git.kernel.org/?p=linux/kernel/git/swarren/linux-rpi.git;a=blob;f=drivers/clk/clk-bcm2835.c;h=67ad16b20b8119cc079e63d5dc7a9da0c79c567c;hb=f680f25c635a1a4327bef34fcbe1e9e3777b546c

(or, see linux-next or Linus Torvald's tree)

Also, please be aware of an error-handling bug there; see:

https://lkml.org/lkml/2012/10/7/75