/*
* We read the real processor speed from the PLL. This is important
* because it is more accurate than computing it from the 32KHz
* counter, if it exists. If we don't have an accurate processor
* speed, all of the peripherals that derive their clocks based on
* this advertised speed will introduce error and sometimes not work
* properly. This function is futher convoluted to still allow configurations
* to do that in case they have really, really old silicon with a
* write-only PLL register, that we need the 32KHz when power management
* "wait" is enabled, and we need to detect if the 32KHz isn't present
* but requested......got it? :-) -- Dan
*/
unsigned long cal_r4koff(void)
{
unsigned long cpu_speed;
unsigned long flags;
unsigned long counter;
spin_lock_irqsave(&time_lock, flags);
/* Power management cares if we don't have a 32KHz counter.
*/
no_au1xxx_32khz = 0;
counter = au_readl(SYS_COUNTER_CNTRL);
if (counter & SYS_CNTRL_E0) {
int trim_divide = 16;
au_writel(counter | SYS_CNTRL_EN1, SYS_COUNTER_CNTRL);
while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_T1S);
/* RTC now ticks at 32.768/16 kHz */
au_writel(trim_divide-1, SYS_RTCTRIM);
while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_T1S);
while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C1S);
au_writel (0, SYS_TOYWRITE);
while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C1S);
cpu_speed = (au_readl(SYS_CPUPLL) & 0x0000003f) *
AU1000_SRC_CLK;
}
else {
/* The 32KHz oscillator isn't running, so assume there
* isn't one and grab the processor speed from the PLL.
* NOTE: some old silicon doesn't allow reading the PLL.
*/
cpu_speed = (au_readl(SYS_CPUPLL) & 0x0000003f) * AU1000_SRC_CLK;
no_au1xxx_32khz = 1;
}
mips_hpt_frequency = cpu_speed;
// Equation: Baudrate = CPU / (SD * 2 * CLKDIV * 16)
set_au1x00_uart_baud_base(cpu_speed / (2 * ((int)(au_readl(SYS_POWERCTRL)&0x03) + 2) * 16));
spin_unlock_irqrestore(&time_lock, flags);
return (cpu_speed / HZ);
}
/*
* Figure out the r4k offset, the amount to increment the compare
* register for each time tick.
* Use the Programmable Counter 1 to do this.
*/
unsigned long cal_r4koff(void)
{
unsigned long count;
unsigned long cpu_speed;
unsigned long start, end;
unsigned long counter;
int trim_divide = 16;
unsigned long flags;
spin_lock_irqsave(&time_lock, flags);
counter = au_readl(SYS_COUNTER_CNTRL);
au_writel(counter | SYS_CNTRL_EN1, SYS_COUNTER_CNTRL);
while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_T1S);
au_writel(trim_divide-1, SYS_RTCTRIM); /* RTC now ticks at 32.768/16 kHz */
while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_T1S);
while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C1S);
au_writel (0, SYS_TOYWRITE);
while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C1S);
start = au_readl(SYS_RTCREAD);
start += 2;
/* wait for the beginning of a new tick */
while (au_readl(SYS_RTCREAD) < start);
/* Start r4k counter. */
write_c0_count(0);
end = start + (32768 / trim_divide)/2; /* wait 0.5 seconds */
while (end > au_readl(SYS_RTCREAD));
count = read_c0_count();
cpu_speed = count * 2;
mips_counter_frequency = count;
set_au1x00_uart_baud_base(((cpu_speed) / 4) / 16);
spin_unlock_irqrestore(&time_lock, flags);
return (cpu_speed / HZ);
}
/*
* We read the real processor speed from the PLL. This is important
* because it is more accurate than computing it from the 32KHz
* counter, if it exists. If we don't have an accurate processor
* speed, all of the peripherals that derive their clocks based on
* this advertised speed will introduce error and sometimes not work
* properly. This function is futher convoluted to still allow configurations
* to do that in case they have really, really old silicon with a
* write-only PLL register, that we need the 32KHz when power management
* "wait" is enabled, and we need to detect if the 32KHz isn't present
* but requested......got it? :-) -- Dan
*/
unsigned long cal_r4koff(void)
{
unsigned long cpu_speed;
unsigned long flags;
unsigned long counter;
spin_lock_irqsave(&time_lock, flags);
/* Power management cares if we don't have a 32KHz counter.
*/
no_au1xxx_32khz = 0;
counter = au_readl(SYS_COUNTER_CNTRL);
if (counter & SYS_CNTRL_E0) {
int trim_divide = 16;
au_writel(counter | SYS_CNTRL_EN1, SYS_COUNTER_CNTRL);
while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_T1S);
/* RTC now ticks at 32.768/16 kHz */
au_writel(trim_divide-1, SYS_RTCTRIM);
while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_T1S);
while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C1S);
au_writel (0, SYS_TOYWRITE);
while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C1S);
#if defined(CONFIG_AU1000_USE32K)
{
unsigned long start, end, count;
start = au_readl(SYS_RTCREAD);
start += 2;
/* wait for the beginning of a new tick
*/
while (au_readl(SYS_RTCREAD) < start);
/* Start r4k counter.
*/
write_c0_count(0);
/* Wait 0.5 seconds.
*/
end = start + (32768 / trim_divide)/2;
while (end > au_readl(SYS_RTCREAD));
count = read_c0_count();
cpu_speed = count * 2;
}
#else
cpu_speed = (au_readl(SYS_CPUPLL) & 0x0000003f) *
AU1000_SRC_CLK;
#endif
}
else {
/* The 32KHz oscillator isn't running, so assume there
* isn't one and grab the processor speed from the PLL.
* NOTE: some old silicon doesn't allow reading the PLL.
*/
cpu_speed = (au_readl(SYS_CPUPLL) & 0x0000003f) * AU1000_SRC_CLK;
no_au1xxx_32khz = 1;
}
mips_hpt_frequency = cpu_speed;
// Equation: Baudrate = CPU / (SD * 2 * CLKDIV * 16)
set_au1x00_uart_baud_base(cpu_speed / (2 * ((int)(au_readl(SYS_POWERCTRL)&0x03) + 2) * 16));
spin_unlock_irqrestore(&time_lock, flags);
return (cpu_speed / HZ);
}
static int pm_do_freq(ctl_table * ctl, int write, struct file *file,
void *buffer, size_t * len)
{
int retval = 0, i;
unsigned long val, pll;
#define TMPBUFLEN 64
#define MAX_CPU_FREQ 396
char buf[TMPBUFLEN], *p;
unsigned long flags, intc0_mask, intc1_mask;
unsigned long old_baud_base, old_cpu_freq, baud_rate, old_clk,
old_refresh;
unsigned long new_baud_base, new_cpu_freq, new_clk, new_refresh;
spin_lock_irqsave(&pm_lock, flags);
if (!write) {
*len = 0;
} else {
/* Parse the new frequency */
if (*len > TMPBUFLEN - 1) {
spin_unlock_irqrestore(&pm_lock, flags);
return -EFAULT;
}
if (copy_from_user(buf, buffer, *len)) {
spin_unlock_irqrestore(&pm_lock, flags);
return -EFAULT;
}
buf[*len] = 0;
p = buf;
val = simple_strtoul(p, &p, 0);
if (val > MAX_CPU_FREQ) {
spin_unlock_irqrestore(&pm_lock, flags);
return -EFAULT;
}
pll = val / 12;
if ((pll > 33) || (pll < 7)) { /* 396 MHz max, 84 MHz min */
/* revisit this for higher speed cpus */
spin_unlock_irqrestore(&pm_lock, flags);
return -EFAULT;
}
old_baud_base = get_au1x00_uart_baud_base();
old_cpu_freq = get_au1x00_speed();
new_cpu_freq = pll * 12 * 1000000;
new_baud_base = (new_cpu_freq / (2 * ((int)(au_readl(SYS_POWERCTRL)&0x03) + 2) * 16));
set_au1x00_speed(new_cpu_freq);
set_au1x00_uart_baud_base(new_baud_base);
old_refresh = au_readl(MEM_SDREFCFG) & 0x1ffffff;
new_refresh =
((old_refresh * new_cpu_freq) /
old_cpu_freq) | (au_readl(MEM_SDREFCFG) & ~0x1ffffff);
au_writel(pll, SYS_CPUPLL);
au_sync_delay(1);
au_writel(new_refresh, MEM_SDREFCFG);
au_sync_delay(1);
for (i = 0; i < 4; i++) {
if (au_readl
(UART_BASE + UART_MOD_CNTRL +
i * 0x00100000) == 3) {
old_clk =
au_readl(UART_BASE + UART_CLK +
i * 0x00100000);
// baud_rate = baud_base/clk
baud_rate = old_baud_base / old_clk;
/* we won't get an exact baud rate and the error
* could be significant enough that our new
* calculation will result in a clock that will
* give us a baud rate that's too far off from
* what we really want.
*/
if (baud_rate > 100000)
baud_rate = 115200;
else if (baud_rate > 50000)
baud_rate = 57600;
else if (baud_rate > 30000)
baud_rate = 38400;
else if (baud_rate > 17000)
baud_rate = 19200;
else
(baud_rate = 9600);
// new_clk = new_baud_base/baud_rate
new_clk = new_baud_base / baud_rate;
au_writel(new_clk,
UART_BASE + UART_CLK +
i * 0x00100000);
au_sync_delay(10);
}
}
}
/* We don't want _any_ interrupts other than
* match20. Otherwise our calibrate_delay()
* calculation will be off, potentially a lot.
*/
intc0_mask = save_local_and_disable(0);
intc1_mask = save_local_and_disable(1);
local_enable_irq(AU1000_TOY_MATCH2_INT);
spin_unlock_irqrestore(&pm_lock, flags);
calibrate_delay();
restore_local_and_enable(0, intc0_mask);
restore_local_and_enable(1, intc1_mask);
return retval;
}
