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authorwdenk <wdenk>2003-05-31 18:35:21 +0000
committerwdenk <wdenk>2003-05-31 18:35:21 +0000
commit7a8e9bed17d7924a9c5c4699b1f6a3a0359524ed (patch)
tree5c273df9c5efa7b1b6a4ca88904e48039ef591e8 /drivers/ds1722.c
parent3b57fe0a70b903f4db66c558bb9828bc58acf06b (diff)
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* Patch by Marc Singer, 29 May 2003:
Fixed rarp boot method for IA32 and other little-endian CPUs. * Patch by Marc Singer, 28 May 2003: Added port I/O commands. * Patch by Matthew McClintock, 28 May 2003 - cpu/mpc824x/start.S: fix relocation code when booting from RAM - minor patches for utx8245 * Patch by Daniel Engström, 28 May 2003: x86 update * Patch by Dave Ellis, 9 May 2003 + 27 May 2003: add nand flash support to SXNI855T configuration fix/extend nand flash support: - fix 'nand erase' command so does not erase bad blocks - fix 'nand write' command so does not write to bad blocks - fix nand_probe() so handles no flash detected properly - add doc/README.nand - add .jffs2 and .oob options to nand read/write - add 'nand bad' command to list bad blocks - add 'clean' option to 'nand erase' to write JFFS2 clean markers - make NAND read/write faster * Patch by Rune Torgersen, 23 May 2003: Update for MPC8266ADS board
Diffstat (limited to 'drivers/ds1722.c')
-rw-r--r--drivers/ds1722.c142
1 files changed, 142 insertions, 0 deletions
diff --git a/drivers/ds1722.c b/drivers/ds1722.c
new file mode 100644
index 0000000..34eb80c
--- /dev/null
+++ b/drivers/ds1722.c
@@ -0,0 +1,142 @@
+
+#include <common.h>
+
+#include <ssi.h>
+
+#ifdef CONFIG_DS1722
+
+static void ds1722_select(int dev)
+{
+ ssi_set_interface(4096, 0, 0, 0);
+ ssi_chip_select(0);
+ udelay(1);
+ ssi_chip_select(dev);
+ udelay(1);
+}
+
+
+u8 ds1722_read(int dev, int addr)
+{
+ u8 res;
+
+ ds1722_select(dev);
+
+ ssi_tx_byte(addr);
+ res = ssi_rx_byte();
+
+ ssi_chip_select(0);
+
+ return res;
+}
+
+void ds1722_write(int dev, int addr, u8 data)
+{
+ ds1722_select(dev);
+
+ ssi_tx_byte(0x80|addr);
+ ssi_tx_byte(data);
+
+ ssi_chip_select(0);
+}
+
+
+u16 ds1722_temp(int dev, int resolution)
+{
+ static int useconds[] = {
+ 75000, 150000, 300000, 600000, 1200000
+ };
+ char temp;
+ u16 res;
+
+
+ /* set up the desired resulotion ... */
+ ds1722_write(dev, 0, 0xe0 | (resolution << 1));
+
+ /* wait while the chip measures the tremperature */
+ udelay(useconds[resolution]);
+
+ res = (temp = ds1722_read(dev, 2)) << 8;
+
+ if (temp < 0) {
+ temp = (16 - (ds1722_read(dev, 1) >> 4)) & 0x0f;
+ } else {
+ temp = (ds1722_read(dev, 1) >> 4);
+ }
+
+ switch (temp) {
+ case 0:
+ /* .0000 */
+ break;
+ case 1:
+ /* .0625 */
+ res |=1;
+ break;
+ case 2:
+ /* .1250 */
+ res |=1;
+ break;
+ case 3:
+ /* .1875 */
+ res |=2;
+ break;
+ case 4:
+ /* .2500 */
+ res |=3;
+ break;
+ case 5:
+ /* .3125 */
+ res |=3;
+ break;
+ case 6:
+ /* .3750 */
+ res |=4;
+ break;
+ case 7:
+ /* .4375 */
+ res |=4;
+ break;
+ case 8:
+ /* .5000 */
+ res |=5;
+ break;
+ case 9:
+ /* .5625 */
+ res |=6;
+ break;
+ case 10:
+ /* .6250 */
+ res |=6;
+ break;
+ case 11:
+ /* .6875 */
+ res |=7;
+ break;
+ case 12:
+ /* .7500 */
+ res |=8;
+ break;
+ case 13:
+ /* .8125 */
+ res |=8;
+ break;
+ case 14:
+ /* .8750 */
+ res |=9;
+ break;
+ case 15:
+ /* .9375 */
+ res |=9;
+ break;
+ }
+ return res;
+
+}
+
+int ds1722_probe(int dev)
+{
+ u16 temp = ds1722_temp(dev, DS1722_RESOLUTION_12BIT);
+ printf("%d.%d deg C\n\n", (char)(temp >> 8), temp & 0xff);
+ return 0;
+}
+
+#endif