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authorSergei Shtylyov <sshtylyov@ru.mvista.com>2008-03-27 16:09:31 +0300
committerRalf Baechle <ralf@linux-mips.org>2008-04-01 15:46:34 +0100
commit758e285faca4db948ecddefb523007255b29cdb7 (patch)
tree530fb34442234b04afe0972d6765bbc7f17ba0f6
parentb1ec4c8e483d0d00d3114eafdb2c85c1cf3ed4ae (diff)
[MIPS] Alchemy: work around clock misdetection on early Au1000
Work around the CPU clock miscalculation on Au1000DA/HA/HB due the sys_cpupll register being write-only, i.e. actually do what the comment before cal_r4off() function advertised for years but the code failed at. This is achieved by just giving user a chance to define the clock explicitly in the board config. via CONFIG_SOC_AU1000_FREQUENCY option, defaulting to 396 MHz if the option is not given... The patch is based on the AMD's big unpublished patch, the issue seems to be an undocumented errata (or feature :-)... Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
-rw-r--r--arch/mips/au1000/common/cputable.c36
-rw-r--r--arch/mips/au1000/common/setup.c13
-rw-r--r--arch/mips/au1000/common/time.c24
-rw-r--r--include/asm-mips/mach-au1x00/au1000.h1
4 files changed, 43 insertions, 31 deletions
diff --git a/arch/mips/au1000/common/cputable.c b/arch/mips/au1000/common/cputable.c
index d8df5fdb045f..5c0d35d6e22a 100644
--- a/arch/mips/au1000/common/cputable.c
+++ b/arch/mips/au1000/common/cputable.c
@@ -22,24 +22,24 @@ struct cpu_spec* cur_cpu_spec[NR_CPUS];
/* With some thought, we can probably use the mask to reduce the
* size of the table.
*/
-struct cpu_spec cpu_specs[] = {
- { 0xffffffff, 0x00030100, "Au1000 DA", 1, 0 },
- { 0xffffffff, 0x00030201, "Au1000 HA", 1, 0 },
- { 0xffffffff, 0x00030202, "Au1000 HB", 1, 0 },
- { 0xffffffff, 0x00030203, "Au1000 HC", 1, 1 },
- { 0xffffffff, 0x00030204, "Au1000 HD", 1, 1 },
- { 0xffffffff, 0x01030200, "Au1500 AB", 1, 1 },
- { 0xffffffff, 0x01030201, "Au1500 AC", 0, 1 },
- { 0xffffffff, 0x01030202, "Au1500 AD", 0, 1 },
- { 0xffffffff, 0x02030200, "Au1100 AB", 1, 1 },
- { 0xffffffff, 0x02030201, "Au1100 BA", 1, 1 },
- { 0xffffffff, 0x02030202, "Au1100 BC", 1, 1 },
- { 0xffffffff, 0x02030203, "Au1100 BD", 0, 1 },
- { 0xffffffff, 0x02030204, "Au1100 BE", 0, 1 },
- { 0xffffffff, 0x03030200, "Au1550 AA", 0, 1 },
- { 0xffffffff, 0x04030200, "Au1200 AB", 0, 0 },
- { 0xffffffff, 0x04030201, "Au1200 AC", 1, 0 },
- { 0x00000000, 0x00000000, "Unknown Au1xxx", 1, 0 },
+struct cpu_spec cpu_specs[] = {
+ { 0xffffffff, 0x00030100, "Au1000 DA", 1, 0, 1 },
+ { 0xffffffff, 0x00030201, "Au1000 HA", 1, 0, 1 },
+ { 0xffffffff, 0x00030202, "Au1000 HB", 1, 0, 1 },
+ { 0xffffffff, 0x00030203, "Au1000 HC", 1, 1, 0 },
+ { 0xffffffff, 0x00030204, "Au1000 HD", 1, 1, 0 },
+ { 0xffffffff, 0x01030200, "Au1500 AB", 1, 1, 0 },
+ { 0xffffffff, 0x01030201, "Au1500 AC", 0, 1, 0 },
+ { 0xffffffff, 0x01030202, "Au1500 AD", 0, 1, 0 },
+ { 0xffffffff, 0x02030200, "Au1100 AB", 1, 1, 0 },
+ { 0xffffffff, 0x02030201, "Au1100 BA", 1, 1, 0 },
+ { 0xffffffff, 0x02030202, "Au1100 BC", 1, 1, 0 },
+ { 0xffffffff, 0x02030203, "Au1100 BD", 0, 1, 0 },
+ { 0xffffffff, 0x02030204, "Au1100 BE", 0, 1, 0 },
+ { 0xffffffff, 0x03030200, "Au1550 AA", 0, 1, 0 },
+ { 0xffffffff, 0x04030200, "Au1200 AB", 0, 0, 0 },
+ { 0xffffffff, 0x04030201, "Au1200 AC", 1, 0, 0 },
+ { 0x00000000, 0x00000000, "Unknown Au1xxx", 1, 0, 0 }
};
void
diff --git a/arch/mips/au1000/common/setup.c b/arch/mips/au1000/common/setup.c
index d885e3848ec6..9e4ab80caab6 100644
--- a/arch/mips/au1000/common/setup.c
+++ b/arch/mips/au1000/common/setup.c
@@ -57,7 +57,7 @@ void __init plat_mem_setup(void)
{
struct cpu_spec *sp;
char *argptr;
- unsigned long prid, cpupll, bclk = 1;
+ unsigned long prid, cpufreq, bclk = 1;
set_cpuspec();
sp = cur_cpu_spec[0];
@@ -65,8 +65,15 @@ void __init plat_mem_setup(void)
board_setup(); /* board specific setup */
prid = read_c0_prid();
- cpupll = (au_readl(0xB1900060) & 0x3F) * 12;
- printk("(PRId %08lx) @ %ldMHZ\n", prid, cpupll);
+ if (sp->cpu_pll_wo)
+#ifdef CONFIG_SOC_AU1000_FREQUENCY
+ cpufreq = CONFIG_SOC_AU1000_FREQUENCY / 1000000;
+#else
+ cpufreq = 396;
+#endif
+ else
+ cpufreq = (au_readl(SYS_CPUPLL) & 0x3F) * 12;
+ printk(KERN_INFO "(PRID %08lx) @ %ld MHz\n", prid, cpufreq);
bclk = sp->cpu_bclk;
if (bclk)
diff --git a/arch/mips/au1000/common/time.c b/arch/mips/au1000/common/time.c
index f113b512d7b1..e122bbc6cd88 100644
--- a/arch/mips/au1000/common/time.c
+++ b/arch/mips/au1000/common/time.c
@@ -209,18 +209,22 @@ unsigned long cal_r4koff(void)
while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C1S);
au_writel(0, SYS_TOYWRITE);
while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C1S);
+ } else
+ no_au1xxx_32khz = 1;
- 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.
- */
+ /*
+ * On early Au1000, sys_cpupll was write-only. Since these
+ * silicon versions of Au1000 are not sold by AMD, we don't bend
+ * over backwards trying to determine the frequency.
+ */
+ if (cur_cpu_spec[0]->cpu_pll_wo)
+#ifdef CONFIG_SOC_AU1000_FREQUENCY
+ cpu_speed = CONFIG_SOC_AU1000_FREQUENCY;
+#else
+ cpu_speed = 396000000;
+#endif
+ else
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));
diff --git a/include/asm-mips/mach-au1x00/au1000.h b/include/asm-mips/mach-au1x00/au1000.h
index cb18af989645..5bb57bf2b9d7 100644
--- a/include/asm-mips/mach-au1x00/au1000.h
+++ b/include/asm-mips/mach-au1x00/au1000.h
@@ -1786,6 +1786,7 @@ struct cpu_spec {
char *cpu_name;
unsigned char cpu_od; /* Set Config[OD] */
unsigned char cpu_bclk; /* Enable BCLK switching */
+ unsigned char cpu_pll_wo; /* sys_cpupll reg. write-only */
};
extern struct cpu_spec cpu_specs[];

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