--- /dev/null
+#include "linux_syscall.h"
+#include "linux_console.h"
+
+int log2(int value)
+{
+ /* __builtin_bsr is a exactly equivalent to the x86 machine
+ * instruction with the exception that it returns -1
+ * when the value presented to it is zero.
+ * Otherwise __builtin_bsr returns the zero based index of
+ * the highest bit set.
+ */
+ return __builtin_bsr(value);
+}
+
+
+static int smbus_read_byte(unsigned device, unsigned address)
+{
+ static const unsigned char dimm[] = {
+0x80, 0x08, 0x07, 0x0d, 0x0a, 0x02, 0x48, 0x00, 0x04, 0x60, 0x70, 0x02, 0x82, 0x08, 0x08, 0x01,
+0x0e, 0x04, 0x0c, 0x01, 0x02, 0x20, 0x00, 0x75, 0x70, 0x00, 0x00, 0x48, 0x30, 0x48, 0x2a, 0x40,
+0x80, 0x80, 0x45, 0x45, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x33,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+
+0x80, 0x08, 0x07, 0x0d, 0x0a, 0x02, 0x48, 0x00, 0x04, 0x60, 0x70, 0x02, 0x82, 0x08, 0x08, 0x01,
+0x0e, 0x04, 0x0c, 0x01, 0x02, 0x20, 0x00, 0x75, 0x70, 0x00, 0x00, 0x48, 0x30, 0x48, 0x2a, 0x40,
+0x80, 0x80, 0x45, 0x45, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x33,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ };
+ return dimm[(device << 8) + address];
+}
+
+#define SMBUS_MEM_DEVICE_START 0x00
+#define SMBUS_MEM_DEVICE_END 0x01
+#define SMBUS_MEM_DEVICE_INC 1
+
+/* Function 2 */
+#define DRAM_CONFIG_HIGH 0x94
+#define DCH_MEMCLK_SHIFT 20
+#define DCH_MEMCLK_MASK 7
+#define DCH_MEMCLK_100MHZ 0
+#define DCH_MEMCLK_133MHZ 2
+#define DCH_MEMCLK_166MHZ 5
+#define DCH_MEMCLK_200MHZ 7
+
+/* Function 3 */
+#define NORTHBRIDGE_CAP 0xE8
+#define NBCAP_128Bit 0x0001
+#define NBCAP_MP 0x0002
+#define NBCAP_BIG_MP 0x0004
+#define NBCAP_ECC 0x0004
+#define NBCAP_CHIPKILL_ECC 0x0010
+#define NBCAP_MEMCLK_SHIFT 5
+#define NBCAP_MEMCLK_MASK 3
+#define NBCAP_MEMCLK_100MHZ 3
+#define NBCAP_MEMCLK_133MHZ 2
+#define NBCAP_MEMCLK_166MHZ 1
+#define NBCAP_MEMCLK_200MHZ 0
+#define NBCAP_MEMCTRL 0x0100
+
+typedef unsigned char uint8_t;
+typedef unsigned int uint32_t;
+
+static unsigned spd_to_dimm(unsigned device)
+{
+ return (device - SMBUS_MEM_DEVICE_START);
+}
+
+static void disable_dimm(unsigned index)
+{
+ print_debug("disabling dimm");
+ print_debug_hex8(index);
+ print_debug("\r\n");
+#if 0
+ pci_write_config32(PCI_DEV(0, 0x18, 2), DRAM_CSBASE + (((index << 1)+0)<<2), 0);
+ pci_write_config32(PCI_DEV(0, 0x18, 2), DRAM_CSBASE + (((index << 1)+1)<<2), 0);
+#endif
+}
+
+
+struct mem_param {
+ uint8_t cycle_time;
+ uint32_t dch_memclk;
+};
+
+static const struct mem_param *get_mem_param(unsigned min_cycle_time)
+{
+ static const struct mem_param speed[] = {
+ {
+ .cycle_time = 0xa0,
+ .dch_memclk = DCH_MEMCLK_100MHZ << DCH_MEMCLK_SHIFT,
+ },
+ {
+ .cycle_time = 0x75,
+ .dch_memclk = DCH_MEMCLK_133MHZ << DCH_MEMCLK_SHIFT,
+ },
+ {
+ .cycle_time = 0x60,
+ .dch_memclk = DCH_MEMCLK_166MHZ << DCH_MEMCLK_SHIFT,
+ },
+ {
+ .cycle_time = 0x50,
+ .dch_memclk = DCH_MEMCLK_200MHZ << DCH_MEMCLK_SHIFT,
+ },
+ {
+ .cycle_time = 0x00,
+ },
+ };
+ const struct mem_param *param;
+ for(param = &speed[0]; param->cycle_time ; param++) {
+ if (min_cycle_time > (param+1)->cycle_time) {
+ break;
+ }
+ }
+ if (!param->cycle_time) {
+ die("min_cycle_time to low");
+ }
+ return param;
+}
+
+#if 1
+static void debug(int c)
+{
+ print_debug_char(c);
+ print_debug_char('\r');
+ print_debug_char('\n');
+}
+#endif
+static const struct mem_param *spd_set_memclk(void)
+{
+ /* Compute the minimum cycle time for these dimms */
+ const struct mem_param *param;
+ unsigned min_cycle_time, min_latency;
+ unsigned device;
+ uint32_t value;
+
+ static const int latency_indicies[] = { 26, 23, 9 };
+ static const unsigned char min_cycle_times[] = {
+ [NBCAP_MEMCLK_200MHZ] = 0x50, /* 5ns */
+ [NBCAP_MEMCLK_166MHZ] = 0x60, /* 6ns */
+ [NBCAP_MEMCLK_133MHZ] = 0x75, /* 7.5ns */
+ [NBCAP_MEMCLK_100MHZ] = 0xa0, /* 10ns */
+ };
+
+
+#if 0
+ value = pci_read_config32(PCI_DEV(0, 0x18, 3), NORTHBRIDGE_CAP);
+#else
+ value = 0x50;
+#endif
+ min_cycle_time = min_cycle_times[(value >> NBCAP_MEMCLK_SHIFT) & NBCAP_MEMCLK_MASK];
+ min_latency = 2;
+
+#if 1
+ print_debug("min_cycle_time: ");
+ print_debug_hex8(min_cycle_time);
+ print_debug(" min_latency: ");
+ print_debug_hex8(min_latency);
+ print_debug("\r\n");
+#endif
+
+ /* Compute the least latency with the fastest clock supported
+ * by both the memory controller and the dimms.
+ */
+ for(device = SMBUS_MEM_DEVICE_START;
+ device <= SMBUS_MEM_DEVICE_END;
+ device += SMBUS_MEM_DEVICE_INC)
+ {
+ int new_cycle_time, new_latency;
+ int index;
+ int latencies;
+ int latency;
+
+ debug('A');
+ /* First find the supported CAS latencies
+ * Byte 18 for DDR SDRAM is interpreted:
+ * bit 0 == CAS Latency = 1.0
+ * bit 1 == CAS Latency = 1.5
+ * bit 2 == CAS Latency = 2.0
+ * bit 3 == CAS Latency = 2.5
+ * bit 4 == CAS Latency = 3.0
+ * bit 5 == CAS Latency = 3.5
+ * bit 6 == TBD
+ * bit 7 == TBD
+ */
+ new_cycle_time = 0xa0;
+ new_latency = 5;
+
+ latencies = smbus_read_byte(device, 18);
+ if (latencies <= 0) continue;
+
+ debug('B');
+ /* Compute the lowest cas latency supported */
+ latency = log2(latencies) -2;
+
+ /* Loop through and find a fast clock with a low latency */
+ for(index = 0; index < 3; index++, latency++) {
+ int value;
+ debug('C');
+ if ((latency < 2) || (latency > 4) ||
+ (!(latencies & (1 << latency)))) {
+ continue;
+ }
+ debug('D');
+ value = smbus_read_byte(device, latency_indicies[index]);
+ if (value < 0) continue;
+
+ debug('E');
+ /* Only increase the latency if we decreas the clock */
+ if ((value >= min_cycle_time) && (value < new_cycle_time)) {
+ new_cycle_time = value;
+ new_latency = latency;
+#if 1
+ print_debug("device: ");
+ print_debug_hex8(device);
+ print_debug(" new_cycle_time: ");
+ print_debug_hex8(new_cycle_time);
+ print_debug(" new_latency: ");
+ print_debug_hex8(new_latency);
+ print_debug("\r\n");
+#endif
+ }
+ debug('G');
+ }
+ debug('H');
+#if 1
+ print_debug("device: ");
+ print_debug_hex8(device);
+ print_debug(" new_cycle_time: ");
+ print_debug_hex8(new_cycle_time);
+ print_debug(" new_latency: ");
+ print_debug_hex8(new_latency);
+ print_debug("\r\n");
+#endif
+ if (new_latency > 4){
+ continue;
+ }
+ debug('I');
+ /* Does min_latency need to be increased? */
+ if (new_cycle_time > min_cycle_time) {
+ min_cycle_time = new_cycle_time;
+ }
+ /* Does min_cycle_time need to be increased? */
+ if (new_latency > min_latency) {
+ min_latency = new_latency;
+ }
+#if 1
+ print_debug("device: ");
+ print_debug_hex8(device);
+ print_debug(" min_cycle_time: ");
+ print_debug_hex8(min_cycle_time);
+ print_debug(" min_latency: ");
+ print_debug_hex8(min_latency);
+ print_debug("\r\n");
+#endif
+ }
+ /* Make a second pass through the dimms and disable
+ * any that cannot support the selected memclk and cas latency.
+ */
+ for(device = SMBUS_MEM_DEVICE_START;
+ device <= SMBUS_MEM_DEVICE_END;
+ device += SMBUS_MEM_DEVICE_INC)
+ {
+ int latencies;
+ int latency;
+ int index;
+ int value;
+ int dimm;
+ latencies = smbus_read_byte(device, 18);
+ if (latencies <= 0) {
+ goto dimm_err;
+ }
+
+ /* Compute the lowest cas latency supported */
+ latency = log2(latencies) -2;
+
+ /* Walk through searching for the selected latency */
+ for(index = 0; index < 3; index++, latency++) {
+ if (!(latencies & (1 << latency))) {
+ continue;
+ }
+ if (latency == min_latency)
+ break;
+ }
+ /* If I can't find the latency or my index is bad error */
+ if ((latency != min_latency) || (index >= 3)) {
+ goto dimm_err;
+ }
+
+ /* Read the min_cycle_time for this latency */
+ value = smbus_read_byte(device, latency_indicies[index]);
+
+ /* All is good if the selected clock speed
+ * is what I need or slower.
+ */
+ if (value <= min_cycle_time) {
+ continue;
+ }
+ /* Otherwise I have an error, disable the dimm */
+ dimm_err:
+ disable_dimm(spd_to_dimm(device));
+ }
+#if 1
+ print_debug("min_cycle_time: ");
+ print_debug_hex8(min_cycle_time);
+ print_debug(" min_latency: ");
+ print_debug_hex8(min_latency);
+ print_debug("\r\n");
+#endif
+ /* Now that I know the minimum cycle time lookup the memory parameters */
+ param = get_mem_param(min_cycle_time);
+
+#if 0
+ /* Update DRAM Config High with our selected memory speed */
+ value = pci_read_config32(PCI_DEV(0, 0x18, 2), DRAM_CONFIG_HIGH);
+ value &= ~(DCH_MEMCLK_MASK << DCH_MEMCLK_SHIFT);
+ value |= param->dch_memclk;
+ pci_write_config32(PCI_DEV(0, 0x18, 2), DRAM_CONFIG_HIGH, value);
+
+ static const unsigned latencies[] = { 1, 5, 2 };
+ /* Update DRAM Timing Low wiht our selected cas latency */
+ value = pci_read_config32(PCI_DEV(0, 0x18, 2), DRAM_CONFIG_LOW);
+ value &= ~7;
+ value |= latencies[min_latency - 2];
+ pci_write_config32(PCI_DEV(0, 0x18, 2), DRAM_CONFIG_LOW, value);
+#endif
+
+ return param;
+}
+
+static void main(void)
+{
+ const struct mem_param *param;
+ param = spd_set_memclk();
+ _exit(0);
+}
projects / coreboot.git / blobdiff