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- Calculate clock frequency using PLL registers

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This commit is contained in:
Oleksandr Tymoshenko 2009-05-23 18:18:06 +00:00
parent 070f07e3de
commit 5dc8f9e2ee
1 changed files with 15 additions and 1 deletions
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16
sys/mips/atheros/uart_bus_ar71xx.c
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@ -67,6 +67,20 @@ static int
uart_ar71xx_probe(device_t dev)
{
struct uart_softc *sc;
uint32_t pll_config, div;
uint64_t freq;
/* PLL freq */
pll_config = ATH_READ_REG(AR71XX_PLL_CPU_CONFIG);
div = ((pll_config >> PLL_FB_SHIFT) & PLL_FB_MASK) + 1;
freq = div * AR71XX_BASE_FREQ;
/* CPU freq */
div = ((pll_config >> PLL_CPU_DIV_SEL_SHIFT) & PLL_CPU_DIV_SEL_MASK)
+ 1;
freq = freq / div;
/* AHB freq */
div = (((pll_config >> PLL_AHB_DIV_SHIFT) & PLL_AHB_DIV_MASK) + 1) * 2;
freq = freq / div;
sc = device_get_softc(dev);
sc->sc_sysdev = SLIST_FIRST(&uart_sysdevs);
@ -79,7 +93,7 @@ uart_ar71xx_probe(device_t dev)
sc->sc_bas.bst = mips_bus_space_generic;
sc->sc_bas.bsh = MIPS_PHYS_TO_KSEG1(AR71XX_UART_ADDR) + 3;
return (uart_bus_probe(dev, 2, 85000000, 0, 0));
return (uart_bus_probe(dev, 2, freq, 0, 0));
}
DRIVER_MODULE(uart, apb, uart_ar71xx_driver, uart_devclass, 0, 0);