diff options
author | Alexandru Gagniuc <mr.nuke.me@gmail.com> | 2013-12-22 21:30:21 -0500 |
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committer | Alexandru Gagniuc <mr.nuke.me@gmail.com> | 2014-01-08 23:03:19 +0100 |
commit | 8226dbbf1d85be662ab6d427ca80c305cf0b719d (patch) | |
tree | 3f284c9b105396fc757245da6db5bee30fd3688e /src/cpu/allwinner/a10/pinmux.c | |
parent | be32f51aa180bd132caa790452b8c0e7920c3afb (diff) |
cpu/allwinner/a10: Refactor and document pinmux API
Include a function to multiplex more than one pin at a time. This
is useful for peripherals that have the same function number for
all their pins.
Since we now have two functions for muxing pins, also document
them.
Change-Id: I53997cc3a2586e3cf749cd672f69fb427659c67f
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-on: http://review.coreboot.org/4565
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Diffstat (limited to 'src/cpu/allwinner/a10/pinmux.c')
-rw-r--r-- | src/cpu/allwinner/a10/pinmux.c | 51 |
1 files changed, 50 insertions, 1 deletions
diff --git a/src/cpu/allwinner/a10/pinmux.c b/src/cpu/allwinner/a10/pinmux.c index 2525de58af..de87440d8f 100644 --- a/src/cpu/allwinner/a10/pinmux.c +++ b/src/cpu/allwinner/a10/pinmux.c @@ -11,7 +11,14 @@ static struct a10_gpio *const gpio = (void *)GPIO_BASE; -void gpio_set_func(u8 port, u8 pin, u8 pad_func) +/** + * \brief Set the pad function of a single pin + * + * @param[in] port GPIO port of the pin (GPA -> GPS) + * @param[in] pin the pin number in the given port (1 -> 31) + * @param[in] pad_func The peripheral function to which to connect this pin + */ +void gpio_set_pin_func(u8 port, u8 pin, u8 pad_func) { u8 reg, bit; u32 reg32; @@ -28,3 +35,45 @@ void gpio_set_func(u8 port, u8 pin, u8 pad_func) reg32 |= (pad_func & 0xf) << bit; write32(reg32, &gpio->port[port].cfg[reg]); } + +/** + * \brief Set the pad function of a group of pins + * + * Multiplex a group of pins to the same pad function. This is useful for + * peripherals that use the same function number for several pins. This function + * allows those pins to be set with a single call. + * + * Example: + * gpio_set_multipin_func(GPB, (1 << 23) | (1 << 22), 2); + * + * @param[in] port GPIO port of the pin (GPA -> GPS) + * @param[in] pin_mask 32-bit mask indicating which pins to re-multiplex. For + * each set bit, the corresponding pin will be multiplexed. + * @param[in] pad_func The peripheral function to which to connect the pins + */ +void gpio_set_multipin_func(u8 port, u32 pin_mask, u8 pad_func) +{ + int j; + u8 reg, bit; + u32 reg32, mask_offset; + + if ((port > GPS)) + return; + + for (reg = 0; reg < 4; reg++) { + mask_offset = 8 * reg; + /* Don't run the inner loop if we're not touching any pins */ + if (!(pin_mask & (0xff << mask_offset))) + continue; + + reg32 = read32(&gpio->port[port].cfg[reg]); + for (j = 0; j < 8; j++) { + if (!(pin_mask & (1 << (j + mask_offset)))) + continue; + bit = j * 4; + reg32 &= ~(0xf << bit); + reg32 |= (pad_func & 0xf) << bit; + } + write32(reg32, &gpio->port[port].cfg[reg]); + } +} |