Re: [PATCH] clk: new driver for efm32 SoC

[Mike Turquette <mturquette@linaro.org>]

Quoting Uwe Kleine-König (2013-08-14 13:04:53)
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
> Hello,
> 
> I'm not sure if there is a naming convention for #defines in headers below
> dt-bindings. I named my clocks clk_$namefromreferencemanual to have some
> namespacing.
> 
> The clock stuff on the different variants of efm32 are similar, but
> different enough to not be able to use the same driver, so this is only
> for the Giant Gecko (efm32gg) variant, still I used "efm32" in some
> places because the other variants would fit there, too. (For
> include/dt-bindings/clock/efm32-cmu.h I would need some #ifdefs, is that
> OK or should the name of the defines include efm32gg? (That would make
> the names still longer and so more ugly.))

The DT experts should weigh in on having #ifdef's in the header, but I
think we should avoid that. Better to explicitly list the clocks for the
variant used. You can add "gg" to this or not, I don't care, but the
future variants will need some suffix, or maybe their own header.

I'm happy with this patch and can take it for 3.13. Care to add a
changelog?

Regards,
Mike

> 
> Best regards
> Uwe
> 
>  .../devicetree/bindings/clock/efm32-clock.txt      | 11 +++
>  drivers/clk/Makefile                               |  1 +
>  drivers/clk/clk-efm32gg.c                          | 79 ++++++++++++++++++++++
>  include/dt-bindings/clock/efm32-cmu.h              | 42 ++++++++++++
>  include/linux/clk/efm32.h                          |  6 ++
>  5 files changed, 139 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/clock/efm32-clock.txt
>  create mode 100644 drivers/clk/clk-efm32gg.c
>  create mode 100644 include/dt-bindings/clock/efm32-cmu.h
>  create mode 100644 include/linux/clk/efm32.h
> 
> diff --git a/Documentation/devicetree/bindings/clock/efm32-clock.txt b/Documentation/devicetree/bindings/clock/efm32-clock.txt
> new file mode 100644
> index 0000000..263d293
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/efm32-clock.txt
> @@ -0,0 +1,11 @@
> +* Clock bindings for Energy Micro efm32 Giant Gecko's Clock Management Unit
> +
> +Required properties:
> +- compatible: Should be "efm32gg,cmu"
> +- reg: Base address and length of the register set
> +- interrupts: Interrupt used by the CMU
> +- #clock-cells: Should be <1>
> +
> +The clock consumer should specify the desired clock by having the clock ID in
> +its "clocks" phandle cell. The header efm32-clk.h contains a list of available
> +IDs.
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index 4038c2b..99d9ad0 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -11,6 +11,7 @@ obj-$(CONFIG_COMMON_CLK)      += clk-composite.o
>  
>  # SoCs specific
>  obj-$(CONFIG_ARCH_BCM2835)     += clk-bcm2835.o
> +obj-$(CONFIG_ARCH_EFM32)       += clk-efm32gg.o
>  obj-$(CONFIG_ARCH_NOMADIK)     += clk-nomadik.o
>  obj-$(CONFIG_ARCH_HIGHBANK)    += clk-highbank.o
>  obj-$(CONFIG_ARCH_NSPIRE)      += clk-nspire.o
> diff --git a/drivers/clk/clk-efm32gg.c b/drivers/clk/clk-efm32gg.c
> new file mode 100644
> index 0000000..2e63584
> --- /dev/null
> +++ b/drivers/clk/clk-efm32gg.c
> @@ -0,0 +1,79 @@
> +#include <linux/clk.h>
> +#include <linux/io.h>
> +#include <linux/clk-provider.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +
> +#include <dt-bindings/clock/efm32-cmu.h>
> +
> +#define CMU_HFPERCLKEN0                0x44
> +
> +static struct clk *clk[37];
> +static struct clk_onecell_data clk_data = {
> +       .clks = clk,
> +       .clk_num = ARRAY_SIZE(clk),
> +};
> +
> +int __init efm32gg_clk_init(void)
> +{
> +       int i;
> +       struct device_node *np;
> +       void __iomem *base;
> +
> +       for (i = 0; i < ARRAY_SIZE(clk); ++i)
> +               clk[i] = ERR_PTR(-ENOENT);
> +
> +       np = of_find_compatible_node(NULL, NULL, "efm32gg,cmu");
> +       if (!np) {
> +               pr_warn("No efm32gg,cmu node found in device tree\n");
> +               return -ENOENT;
> +       }
> +
> +       base = of_iomap(np, 0);
> +       if (!base) {
> +               pr_warn("Failed to map address range for efm32gg,cmu node\n");
> +               return -EADDRNOTAVAIL;
> +       }
> +
> +       clk[clk_HFXO] = clk_register_fixed_rate(NULL, "HFXO", NULL,
> +                       CLK_IS_ROOT, 48000000);
> +
> +       clk[clk_HFPERCLKUSART0] = clk_register_gate(NULL, "HFPERCLK.USART0",
> +                       "HFXO", 0, base + CMU_HFPERCLKEN0, 0, 0, NULL);
> +       clk[clk_HFPERCLKUSART1] = clk_register_gate(NULL, "HFPERCLK.USART1",
> +                       "HFXO", 0, base + CMU_HFPERCLKEN0, 1, 0, NULL);
> +       clk[clk_HFPERCLKUSART2] = clk_register_gate(NULL, "HFPERCLK.USART2",
> +                       "HFXO", 0, base + CMU_HFPERCLKEN0, 2, 0, NULL);
> +       clk[clk_HFPERCLKUART0] = clk_register_gate(NULL, "HFPERCLK.UART0",
> +                       "HFXO", 0, base + CMU_HFPERCLKEN0, 3, 0, NULL);
> +       clk[clk_HFPERCLKUART1] = clk_register_gate(NULL, "HFPERCLK.UART1",
> +                       "HFXO", 0, base + CMU_HFPERCLKEN0, 4, 0, NULL);
> +       clk[clk_HFPERCLKTIMER0] = clk_register_gate(NULL, "HFPERCLK.TIMER0",
> +                       "HFXO", 0, base + CMU_HFPERCLKEN0, 5, 0, NULL);
> +       clk[clk_HFPERCLKTIMER1] = clk_register_gate(NULL, "HFPERCLK.TIMER1",
> +                       "HFXO", 0, base + CMU_HFPERCLKEN0, 6, 0, NULL);
> +       clk[clk_HFPERCLKTIMER2] = clk_register_gate(NULL, "HFPERCLK.TIMER2",
> +                       "HFXO", 0, base + CMU_HFPERCLKEN0, 7, 0, NULL);
> +       clk[clk_HFPERCLKTIMER3] = clk_register_gate(NULL, "HFPERCLK.TIMER3",
> +                       "HFXO", 0, base + CMU_HFPERCLKEN0, 8, 0, NULL);
> +       clk[clk_HFPERCLKACMP0] = clk_register_gate(NULL, "HFPERCLK.ACMP0",
> +                       "HFXO", 0, base + CMU_HFPERCLKEN0, 9, 0, NULL);
> +       clk[clk_HFPERCLKACMP1] = clk_register_gate(NULL, "HFPERCLK.ACMP1",
> +                       "HFXO", 0, base + CMU_HFPERCLKEN0, 10, 0, NULL);
> +       clk[clk_HFPERCLKI2C0] = clk_register_gate(NULL, "HFPERCLK.I2C0",
> +                       "HFXO", 0, base + CMU_HFPERCLKEN0, 11, 0, NULL);
> +       clk[clk_HFPERCLKI2C1] = clk_register_gate(NULL, "HFPERCLK.I2C1",
> +                       "HFXO", 0, base + CMU_HFPERCLKEN0, 12, 0, NULL);
> +       clk[clk_HFPERCLKGPIO] = clk_register_gate(NULL, "HFPERCLK.GPIO",
> +                       "HFXO", 0, base + CMU_HFPERCLKEN0, 13, 0, NULL);
> +       clk[clk_HFPERCLKVCMP] = clk_register_gate(NULL, "HFPERCLK.VCMP",
> +                       "HFXO", 0, base + CMU_HFPERCLKEN0, 14, 0, NULL);
> +       clk[clk_HFPERCLKPRS] = clk_register_gate(NULL, "HFPERCLK.PRS",
> +                       "HFXO", 0, base + CMU_HFPERCLKEN0, 15, 0, NULL);
> +       clk[clk_HFPERCLKADC0] = clk_register_gate(NULL, "HFPERCLK.ADC0",
> +                       "HFXO", 0, base + CMU_HFPERCLKEN0, 16, 0, NULL);
> +       clk[clk_HFPERCLKDAC0] = clk_register_gate(NULL, "HFPERCLK.DAC0",
> +                       "HFXO", 0, base + CMU_HFPERCLKEN0, 17, 0, NULL);
> +
> +       return of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
> +}
> diff --git a/include/dt-bindings/clock/efm32-cmu.h b/include/dt-bindings/clock/efm32-cmu.h
> new file mode 100644
> index 0000000..b21b91e
> --- /dev/null
> +++ b/include/dt-bindings/clock/efm32-cmu.h
> @@ -0,0 +1,42 @@
> +#ifndef __DT_BINDINGS_CLOCK_EFM32_CMU_H
> +#define __DT_BINDINGS_CLOCK_EFM32_CMU_H
> +
> +#define clk_HFXO               0
> +#define clk_HFRCO              1
> +#define clk_LFXO               2
> +#define clk_LFRCO              3
> +#define clk_ULFRCO             4
> +#define clk_AUXHFRCO           5
> +#define clk_HFCLKNODIV         6
> +#define clk_HFCLK              7
> +#define clk_HFPERCLK           8
> +#define clk_HFCORECLK          9
> +#define clk_LFACLK             10
> +#define clk_LFBCLK             11
> +#define clk_WDOGCLK            12
> +#define clk_HFCORECLKDMA       13
> +#define clk_HFCORECLKAES       14
> +#define clk_HFCORECLKUSBC      15
> +#define clk_HFCORECLKUSB       16
> +#define clk_HFCORECLKLE                17
> +#define clk_HFCORECLKEBI       18
> +#define clk_HFPERCLKUSART0     19
> +#define clk_HFPERCLKUSART1     20
> +#define clk_HFPERCLKUSART2     21
> +#define clk_HFPERCLKUART0      22
> +#define clk_HFPERCLKUART1      23
> +#define clk_HFPERCLKTIMER0     24
> +#define clk_HFPERCLKTIMER1     25
> +#define clk_HFPERCLKTIMER2     26
> +#define clk_HFPERCLKTIMER3     27
> +#define clk_HFPERCLKACMP0      28
> +#define clk_HFPERCLKACMP1      29
> +#define clk_HFPERCLKI2C0       30
> +#define clk_HFPERCLKI2C1       31
> +#define clk_HFPERCLKGPIO       32
> +#define clk_HFPERCLKVCMP       33
> +#define clk_HFPERCLKPRS                34
> +#define clk_HFPERCLKADC0       35
> +#define clk_HFPERCLKDAC0       36
> +
> +#endif /* __DT_BINDINGS_CLOCK_EFM32_CMU_H */
> diff --git a/include/linux/clk/efm32.h b/include/linux/clk/efm32.h
> new file mode 100644
> index 0000000..4032dc0
> --- /dev/null
> +++ b/include/linux/clk/efm32.h
> @@ -0,0 +1,6 @@
> +#ifndef __LINUX_CLK_EFM32_H__
> +#define __LINUX_CLK_EFM32_H__
> +
> +int efm32gg_clk_init(void);
> +
> +#endif /* __LINUX_CLK_EFM32_H__ */
> -- 
> 1.8.4.rc0

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