diff options
Diffstat (limited to 'bsp/at91sam9260/platform/system_clock.c')
| -rw-r--r-- | bsp/at91sam9260/platform/system_clock.c | 362 |
1 files changed, 181 insertions, 181 deletions
diff --git a/bsp/at91sam9260/platform/system_clock.c b/bsp/at91sam9260/platform/system_clock.c index f59aba016c..a8f866fdd6 100644 --- a/bsp/at91sam9260/platform/system_clock.c +++ b/bsp/at91sam9260/platform/system_clock.c @@ -14,270 +14,270 @@ static rt_list_t clocks; struct clk { - char name[32]; - rt_uint32_t rate_hz; - struct clk *parent; - rt_list_t node; + char name[32]; + rt_uint32_t rate_hz; + struct clk *parent; + rt_list_t node; }; static struct clk clk32k = { - "clk32k", - AT91_SLOW_CLOCK, - RT_NULL, - {RT_NULL, RT_NULL}, + "clk32k", + AT91_SLOW_CLOCK, + RT_NULL, + {RT_NULL, RT_NULL}, }; static struct clk main_clk = { - "main", - 0, - RT_NULL, - {RT_NULL, RT_NULL}, + "main", + 0, + RT_NULL, + {RT_NULL, RT_NULL}, }; static struct clk plla = { - "plla", - 0, - RT_NULL, - {RT_NULL, RT_NULL}, + "plla", + 0, + RT_NULL, + {RT_NULL, RT_NULL}, }; static struct clk mck = { - "mck", - 0, - RT_NULL, - {RT_NULL, RT_NULL}, + "mck", + 0, + RT_NULL, + {RT_NULL, RT_NULL}, }; static struct clk uhpck = { - "uhpck", - 0, - RT_NULL, - {RT_NULL, RT_NULL}, + "uhpck", + 0, + RT_NULL, + {RT_NULL, RT_NULL}, }; static struct clk pllb = { - "pllb", - 0, - &main_clk, - {RT_NULL, RT_NULL}, + "pllb", + 0, + &main_clk, + {RT_NULL, RT_NULL}, }; static struct clk udpck = { - "udpck", - 0, - &pllb, - {RT_NULL, RT_NULL}, + "udpck", + 0, + &pllb, + {RT_NULL, RT_NULL}, }; static struct clk *const standard_pmc_clocks[] = { - /* four primary clocks */ - &clk32k, - &main_clk, - &plla, + /* four primary clocks */ + &clk32k, + &main_clk, + &plla, - /* MCK */ - &mck + /* MCK */ + &mck }; /* clocks cannot be de-registered no refcounting necessary */ struct clk *clk_get(const char *id) { - struct clk *clk; - rt_list_t *list; - - for (list = (&clocks)->next; list != &clocks; list = list->next) - { - clk = (struct clk *)rt_list_entry(list, struct clk, node); - if (rt_strcmp(id, clk->name) == 0) - return clk; - } + struct clk *clk; + rt_list_t *list; - return RT_NULL; + for (list = (&clocks)->next; list != &clocks; list = list->next) + { + clk = (struct clk *)rt_list_entry(list, struct clk, node); + if (rt_strcmp(id, clk->name) == 0) + return clk; + } + + return RT_NULL; } rt_uint32_t clk_get_rate(struct clk *clk) { - rt_uint32_t flags; - rt_uint32_t rate; + rt_uint32_t flags; + rt_uint32_t rate; - for (;;) { - rate = clk->rate_hz; - if (rate || !clk->parent) - break; - clk = clk->parent; - } - return rate; + for (;;) { + rate = clk->rate_hz; + if (rate || !clk->parent) + break; + clk = clk->parent; + } + return rate; } static rt_uint32_t at91_pll_rate(struct clk *pll, rt_uint32_t freq, rt_uint32_t reg) { - unsigned mul, div; + unsigned mul, div; - div = reg & 0xff; - mul = (reg >> 16) & 0x7ff; - if (div && mul) { - freq /= div; - freq *= mul + 1; - } else - freq = 0; + div = reg & 0xff; + mul = (reg >> 16) & 0x7ff; + if (div && mul) { + freq /= div; + freq *= mul + 1; + } else + freq = 0; - return freq; + return freq; } static unsigned at91_pll_calc(unsigned main_freq, unsigned out_freq) { - unsigned i, div = 0, mul = 0, diff = 1 << 30; - unsigned ret = (out_freq > 155000000) ? 0xbe00 : 0x3e00; + unsigned i, div = 0, mul = 0, diff = 1 << 30; + unsigned ret = (out_freq > 155000000) ? 0xbe00 : 0x3e00; - /* PLL output max 240 MHz (or 180 MHz per errata) */ - if (out_freq > 240000000) - goto fail; + /* PLL output max 240 MHz (or 180 MHz per errata) */ + if (out_freq > 240000000) + goto fail; - for (i = 1; i < 256; i++) { - int diff1; - unsigned input, mul1; + for (i = 1; i < 256; i++) { + int diff1; + unsigned input, mul1; - /* - * PLL input between 1MHz and 32MHz per spec, but lower - * frequences seem necessary in some cases so allow 100K. - * Warning: some newer products need 2MHz min. - */ - input = main_freq / i; - if (input < 100000) - continue; - if (input > 32000000) - continue; + /* + * PLL input between 1MHz and 32MHz per spec, but lower + * frequences seem necessary in some cases so allow 100K. + * Warning: some newer products need 2MHz min. + */ + input = main_freq / i; + if (input < 100000) + continue; + if (input > 32000000) + continue; - mul1 = out_freq / input; - if (mul1 > 2048) - continue; - if (mul1 < 2) - goto fail; + mul1 = out_freq / input; + if (mul1 > 2048) + continue; + if (mul1 < 2) + goto fail; - diff1 = out_freq - input * mul1; - if (diff1 < 0) - diff1 = -diff1; - if (diff > diff1) { - diff = diff1; - div = i; - mul = mul1; - if (diff == 0) - break; - } - } - if (i == 256 && diff > (out_freq >> 5)) - goto fail; - return ret | ((mul - 1) << 16) | div; + diff1 = out_freq - input * mul1; + if (diff1 < 0) + diff1 = -diff1; + if (diff > diff1) { + diff = diff1; + div = i; + mul = mul1; + if (diff == 0) + break; + } + } + if (i == 256 && diff > (out_freq >> 5)) + goto fail; + return ret | ((mul - 1) << 16) | div; fail: - return 0; + return 0; } static rt_uint32_t at91_usb_rate(struct clk *pll, rt_uint32_t freq, rt_uint32_t reg) { - if (pll == &pllb && (reg & AT91_PMC_USB96M)) - return freq / 2; - else - return freq; + if (pll == &pllb && (reg & AT91_PMC_USB96M)) + return freq / 2; + else + return freq; } /* PLLB generated USB full speed clock init */ static void at91_pllb_usbfs_clock_init(rt_uint32_t main_clock) { - rt_uint32_t at91_pllb_usb_init; - /* - * USB clock init: choose 48 MHz PLLB value, - * disable 48MHz clock during usb peripheral suspend. - * - * REVISIT: assumes MCK doesn't derive from PLLB! - */ - uhpck.parent = &pllb; + rt_uint32_t at91_pllb_usb_init; + /* + * USB clock init: choose 48 MHz PLLB value, + * disable 48MHz clock during usb peripheral suspend. + * + * REVISIT: assumes MCK doesn't derive from PLLB! + */ + uhpck.parent = &pllb; + + at91_pllb_usb_init = at91_pll_calc(main_clock, 48000000 * 2) | AT91_PMC_USB96M; + pllb.rate_hz = at91_pll_rate(&pllb, main_clock, at91_pllb_usb_init); - at91_pllb_usb_init = at91_pll_calc(main_clock, 48000000 * 2) | AT91_PMC_USB96M; - pllb.rate_hz = at91_pll_rate(&pllb, main_clock, at91_pllb_usb_init); - - at91_sys_write(AT91_CKGR_PLLBR, 0); + at91_sys_write(AT91_CKGR_PLLBR, 0); - udpck.rate_hz = at91_usb_rate(&pllb, pllb.rate_hz, at91_pllb_usb_init); - uhpck.rate_hz = at91_usb_rate(&pllb, pllb.rate_hz, at91_pllb_usb_init); + udpck.rate_hz = at91_usb_rate(&pllb, pllb.rate_hz, at91_pllb_usb_init); + uhpck.rate_hz = at91_usb_rate(&pllb, pllb.rate_hz, at91_pllb_usb_init); } static struct clk *at91_css_to_clk(unsigned long css) { - switch (css) { - case AT91_PMC_CSS_SLOW: - return &clk32k; - case AT91_PMC_CSS_MAIN: - return &main_clk; - case AT91_PMC_CSS_PLLA: - return &plla; - case AT91_PMC_CSS_PLLB: - return &pllb; - } + switch (css) { + case AT91_PMC_CSS_SLOW: + return &clk32k; + case AT91_PMC_CSS_MAIN: + return &main_clk; + case AT91_PMC_CSS_PLLA: + return &plla; + case AT91_PMC_CSS_PLLB: + return &pllb; + } - return RT_NULL; + return RT_NULL; } #define false 0 #define true 1 int at91_clock_init(rt_uint32_t main_clock) { - unsigned tmp, freq, mckr; - int i; - int pll_overclock = false; + unsigned tmp, freq, mckr; + int i; + int pll_overclock = false; + + /* + * When the bootloader initialized the main oscillator correctly, + * there's no problem using the cycle counter. But if it didn't, + * or when using oscillator bypass mode, we must be told the speed + * of the main clock. + */ + if (!main_clock) { + do { + tmp = at91_sys_read(AT91_CKGR_MCFR); + } while (!(tmp & AT91_PMC_MAINRDY)); + main_clock = (tmp & AT91_PMC_MAINF) * (AT91_SLOW_CLOCK / 16); + } + main_clk.rate_hz = main_clock; - /* - * When the bootloader initialized the main oscillator correctly, - * there's no problem using the cycle counter. But if it didn't, - * or when using oscillator bypass mode, we must be told the speed - * of the main clock. - */ - if (!main_clock) { - do { - tmp = at91_sys_read(AT91_CKGR_MCFR); - } while (!(tmp & AT91_PMC_MAINRDY)); - main_clock = (tmp & AT91_PMC_MAINF) * (AT91_SLOW_CLOCK / 16); - } - main_clk.rate_hz = main_clock; + /* report if PLLA is more than mildly overclocked */ + plla.rate_hz = at91_pll_rate(&plla, main_clock, at91_sys_read(AT91_CKGR_PLLAR)); + if (plla.rate_hz > 209000000) + pll_overclock = true; + if (pll_overclock) + ;//rt_kprintf("Clocks: PLLA overclocked, %ld MHz\n", plla.rate_hz / 1000000); - /* report if PLLA is more than mildly overclocked */ - plla.rate_hz = at91_pll_rate(&plla, main_clock, at91_sys_read(AT91_CKGR_PLLAR)); - if (plla.rate_hz > 209000000) - pll_overclock = true; - if (pll_overclock) - ;//rt_kprintf("Clocks: PLLA overclocked, %ld MHz\n", plla.rate_hz / 1000000); + at91_pllb_usbfs_clock_init(main_clock); - at91_pllb_usbfs_clock_init(main_clock); + /* + * MCK and CPU derive from one of those primary clocks. + * For now, assume this parentage won't change. + */ + mckr = at91_sys_read(AT91_PMC_MCKR); + mck.parent = at91_css_to_clk(mckr & AT91_PMC_CSS); + freq = mck.parent->rate_hz; + freq /= (1 << ((mckr & AT91_PMC_PRES) >> 2)); /* prescale */ - /* - * MCK and CPU derive from one of those primary clocks. - * For now, assume this parentage won't change. - */ - mckr = at91_sys_read(AT91_PMC_MCKR); - mck.parent = at91_css_to_clk(mckr & AT91_PMC_CSS); - freq = mck.parent->rate_hz; - freq /= (1 << ((mckr & AT91_PMC_PRES) >> 2)); /* prescale */ - - mck.rate_hz = freq / (1 << ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */ + mck.rate_hz = freq / (1 << ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */ - /* Register the PMC's standard clocks */ - rt_list_init(&clocks); - for (i = 0; i < ARRAY_SIZE(standard_pmc_clocks); i++) - rt_list_insert_after(&clocks, &standard_pmc_clocks[i]->node); + /* Register the PMC's standard clocks */ + rt_list_init(&clocks); + for (i = 0; i < ARRAY_SIZE(standard_pmc_clocks); i++) + rt_list_insert_after(&clocks, &standard_pmc_clocks[i]->node); - rt_list_insert_after(&clocks, &pllb.node); - rt_list_insert_after(&clocks, &uhpck.node); - rt_list_insert_after(&clocks, &udpck.node); + rt_list_insert_after(&clocks, &pllb.node); + rt_list_insert_after(&clocks, &uhpck.node); + rt_list_insert_after(&clocks, &udpck.node); - /* MCK and CPU clock are "always on" */ - //clk_enable(&mck); + /* MCK and CPU clock are "always on" */ + //clk_enable(&mck); - /*rt_kprintf("Clocks: CPU %u MHz, master %u MHz, main %u.%03u MHz\n", - freq / 1000000, (unsigned) mck.rate_hz / 1000000, - (unsigned) main_clock / 1000000, - ((unsigned) main_clock % 1000000) / 1000);*///cause blocked + /*rt_kprintf("Clocks: CPU %u MHz, master %u MHz, main %u.%03u MHz\n", + freq / 1000000, (unsigned) mck.rate_hz / 1000000, + (unsigned) main_clock / 1000000, + ((unsigned) main_clock % 1000000) / 1000);*///cause blocked - return 0; + return 0; } /** @@ -285,6 +285,6 @@ int at91_clock_init(rt_uint32_t main_clock) */ void rt_hw_clock_init(void) { - at91_clock_init(18432000); + at91_clock_init(18432000); } |