Re: [U-Boot] [PATCH v7 15/20] tegra: fdt: Add function to return peripheral/clock ID

Simon,

-----Original Message----- From: Simon Glass [mailto:sjg@chromium.org] Sent: Tuesday, February 28, 2012 11:08 AM To: U-Boot Mailing List Cc: Tom Warren; Stephen Warren; Simon Glass; linux-tegra@vger.kernel.org; Jerry Van Baren; Devicetree Discuss Subject: [PATCH v7 15/20] tegra: fdt: Add function to return peripheral/clock ID

A common requirement is to find the clock ID for a peripheral. This is the second cell of the 'clocks' property (the first being the phandle itself).

Signed-off-by: Simon Glass sjg@chromium.org

Changes in v4:

• Add fdtdec function to return peripheral ID

Changes in v6:

• Move peripheral decode function into Tegra's clock.c

Changes in v7:

• Add belts and braces checking of device tree clock ID

arch/arm/cpu/armv7/tegra2/clock.c | 56 ++++++++++++++++++++++++++++++ arch/arm/include/asm/arch-tegra2/clock.h | 13 +++++++ 2 files changed, 69 insertions(+), 0 deletions(-)

diff --git a/arch/arm/cpu/armv7/tegra2/clock.c b/arch/arm/cpu/armv7/tegra2/clock.c index 11d2346..959322b 100644 --- a/arch/arm/cpu/armv7/tegra2/clock.c +++ b/arch/arm/cpu/armv7/tegra2/clock.c @@ -28,6 +28,7 @@ #include <asm/arch/tegra2.h> #include <common.h> #include <div64.h> +#include <fdtdec.h>

/*

• This is our record of the current clock rate of each clock. We don't @@

-918,6 +919,61 @@ void clock_ll_start_uart(enum periph_id periph_id) reset_set_enable(periph_id, 0); }

+/*

• • Convert a device tree clock ID to our peripheral ID. They are mostly
• • the same but we are very cautious so we check that a valid clock ID

+is

• • provided.
• • @param clk_id Clock ID according to tegra2 device tree binding
• • @return peripheral ID, or PERIPH_ID_NONE if the clock ID is invalid

+*/ static enum periph_id clk_id_to_periph_id(int clk_id) {

• if (clk_id > 95)

• return PERIPH_ID_NONE;
  

• switch (clk_id) {
• case 1:
• case 2:
• case 7:
• case 10:
• case 20:
• case 30:
• case 35:
• case 49:
• case 56:
• case 74:
• case 76:
• case 77:
• case 78:
• case 79:
• case 80:
• case 81:
• case 82:
• case 83:
• case 91:
• case 95:

• return PERIPH_ID_NONE;
  

• default:

• return clk_id;
  

• }

+}

+int clock_decode_periph_id(const void *blob, int node) {

• enum periph_id id;
• u32 cell[2];
• int err;
• err = fdtdec_get_int_array(blob, node, "clocks", cell,

• 		   ARRAY_SIZE(cell));
  

This call to fdtdec_get_int_array() breaks Harmony and Ventana builds, since they're not yet DT-enabled (CONFIG_OF_CONTROL isn't #defined).

I'd fix this myself, but I'm not sure what the correct fix is to keep Harmony/Ventana building & booting.

Please fix, test on all Tegra2 builds (MAKEALL -s tegra2) and resend. Thanks.

Tom

• if (err)

• return -1;
  

• id = clk_id_to_periph_id(cell[1]);
• assert(clock_periph_id_isvalid(id));
• return id;

+}

int clock_verify(void) { struct clk_pll *pll = get_pll(CLOCK_ID_PERIPH); diff --git a/arch/arm/include/asm/arch-tegra2/clock.h b/arch/arm/include/asm/arch- tegra2/clock.h index 080ef18..6b12c76 100644 --- a/arch/arm/include/asm/arch-tegra2/clock.h +++ b/arch/arm/include/asm/arch-tegra2/clock.h @@ -177,6 +177,7 @@ enum periph_id { PERIPH_ID_CRAM2,

PERIPH_ID_COUNT,

• PERIPH_ID_NONE = -1,

};

/* Converts a clock number to a clock register: 0=L, 1=H, 2=U */ @@ -355,6 +356,18 @@ unsigned clock_get_rate(enum clock_id clkid); */ void clock_ll_start_uart(enum periph_id periph_id);

+/**

• • Decode a peripheral ID from a device tree node.
• • This works by looking up the peripheral's 'clocks' node and reading

+out

• • the second cell, which is the clock number / peripheral ID.
• • @param blob FDT blob to use
• • @param node Node to look at
• • @return peripheral ID, or PERIPH_ID_NONE if none */ enum periph_id

+clock_decode_periph_id(const void *blob, int node);

/*

• Checks that clocks are valid and prints a warning if not

-- 1.7.7.3