From 4cd7a2f1aedb2008004e110d31ce831895139fa0 Mon Sep 17 00:00:00 2001 From: Peter Ujfalusi Date: Mon, 10 Sep 2012 13:46:22 +0300 Subject: [PATCH] mfd: twl-core: Add API to query the HFCLK rate CFG_BOOT register's HFCLK_FREQ field hold information about the used HFCLK frequency. Add possibility for users to get the configured rate based on this register. This register was configured during boot, without it the chip would not operate correctly, so we can trust on this information. Signed-off-by: Peter Ujfalusi Acked-by: Samuel Ortiz Signed-off-by: Mark Brown --- drivers/mfd/twl-core.c | 32 ++++++++++++++++++++++++++++++++ include/linux/i2c/twl.h | 1 + 2 files changed, 33 insertions(+) diff --git a/drivers/mfd/twl-core.c b/drivers/mfd/twl-core.c index 1c32afed28aa..f162b68e78a8 100644 --- a/drivers/mfd/twl-core.c +++ b/drivers/mfd/twl-core.c @@ -552,6 +552,38 @@ int twl_get_version(void) } EXPORT_SYMBOL_GPL(twl_get_version); +/** + * twl_get_hfclk_rate - API to get TWL external HFCLK clock rate. + * + * Api to get the TWL HFCLK rate based on BOOT_CFG register. + */ +int twl_get_hfclk_rate(void) +{ + u8 ctrl; + int rate; + + twl_i2c_read_u8(TWL_MODULE_PM_MASTER, &ctrl, R_CFG_BOOT); + + switch (ctrl & 0x3) { + case HFCLK_FREQ_19p2_MHZ: + rate = 19200000; + break; + case HFCLK_FREQ_26_MHZ: + rate = 26000000; + break; + case HFCLK_FREQ_38p4_MHZ: + rate = 38400000; + break; + default: + pr_err("TWL4030: HFCLK is not configured\n"); + rate = -EINVAL; + break; + } + + return rate; +} +EXPORT_SYMBOL_GPL(twl_get_hfclk_rate); + static struct device * add_numbered_child(unsigned chip, const char *name, int num, void *pdata, unsigned pdata_len, diff --git a/include/linux/i2c/twl.h b/include/linux/i2c/twl.h index 7ea898c55a60..ac6488c9f250 100644 --- a/include/linux/i2c/twl.h +++ b/include/linux/i2c/twl.h @@ -188,6 +188,7 @@ int twl_i2c_read(u8 mod_no, u8 *value, u8 reg, unsigned num_bytes); int twl_get_type(void); int twl_get_version(void); +int twl_get_hfclk_rate(void); int twl6030_interrupt_unmask(u8 bit_mask, u8 offset); int twl6030_interrupt_mask(u8 bit_mask, u8 offset); -- 2.20.1