[PATCH 2/5] clk: bcm2835: enable management of PCM clock

Remi Pommarel
2016-01-10T12:30:14Z

On Sun, Jan 10, 2016 at 01:17:17PM +0100, Martin Sperl wrote:
> >
> > Presumably just making the code not rely on having a define for the
> > number of clocks would deal with the problem (eg, using ARRAY_SIZE
> > internally).
> ARRAY_SIZE would work fine, but the code is:
>
> #include <dt-bindings/clock/bcm2835.h>
> ...
> struct bcm2835_cprman {
> struct device *dev;
> void __iomem *regs;
> spinlock_t regs_lock;
> const char *osc_name;
>
> struct clk_onecell_data onecell;
> struct clk *clks[BCM2835_CLOCK_COUNT];
> };
> ...
> static int bcm2835_clk_probe(struct platform_device *pdev)
> {
> ...
> clks[BCM2835_PLLA_CORE] =
> bcm2835_register_pll_divider(cprman, &bcm2835_plla_core_data);
> ...
> clks[BCM2835_CLOCK_PCM] =
> bcm2835_register_clock(cprman, &bcm2835_clock_pcm_data);
> ...
> }
>
> So the Array size is defined by the dt-bindings.
>
> What you propose is a major change to the clock framework, so I would
> hope that Eric (the original author of this clock-driver) would address
> it.
>
> Maybe someone has a better idea for a pattern to use to achieve
> the required while maintaining ?synchronization? between defines
> inside the dt-binding and the driver.
>

Why not just get rid of BCM2835_CLOCK_COUNT and use an internal clock
count ? Something like the patch attached at the end of the mail. This
has the downside to be more careful when adding a new clock.

If it is not ok, I could try to modify the clk driver to use Mark's
solution if you want.

Regards,

--
Remi

--------------------------------->8---------------------------------------
diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
index 015e687..f558c5b 100644
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -281,6 +281,8 @@
#define LOCK_TIMEOUT_NS 100000000
#define BCM2835_MAX_FB_RATE 1750000000u

+#define BCM2835_CLOCK_MAX BCM2835_CLOCK_PCM
+
struct bcm2835_cprman {
struct device *dev;
void __iomem *regs;
@@ -288,7 +290,7 @@ struct bcm2835_cprman {
const char *osc_name;

struct clk_onecell_data onecell;
- struct clk *clks[BCM2835_CLOCK_COUNT];
+ struct clk *clks[BCM2835_CLOCK_MAX + 1];
};

static inline void cprman_write(struct bcm2835_cprman *cprman, u32 reg, u32 val)