summaryrefslogtreecommitdiff
path: root/arch/powerpc/cpu/mpc512x/i2c.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/cpu/mpc512x/i2c.c')
-rw-r--r--arch/powerpc/cpu/mpc512x/i2c.c403
1 files changed, 403 insertions, 0 deletions
diff --git a/arch/powerpc/cpu/mpc512x/i2c.c b/arch/powerpc/cpu/mpc512x/i2c.c
new file mode 100644
index 0000000..e2d9097
--- /dev/null
+++ b/arch/powerpc/cpu/mpc512x/i2c.c
@@ -0,0 +1,403 @@
+/*
+ * (C) Copyright 2003 - 2009
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ * Based on the MPC5xxx code.
+ */
+
+#include <common.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#ifdef CONFIG_HARD_I2C
+
+#include <i2c.h>
+
+/* by default set I2C bus 0 active */
+static unsigned int bus_num __attribute__ ((section (".data"))) = 0;
+
+#define I2C_TIMEOUT 100
+#define I2C_RETRIES 3
+
+struct mpc512x_i2c_tap {
+ int scl2tap;
+ int tap2tap;
+};
+
+static int mpc_reg_in(volatile u32 *reg);
+static void mpc_reg_out(volatile u32 *reg, int val, int mask);
+static int wait_for_bb(void);
+static int wait_for_pin(int *status);
+static int do_address(uchar chip, char rdwr_flag);
+static int send_bytes(uchar chip, char *buf, int len);
+static int receive_bytes(uchar chip, char *buf, int len);
+static int mpc_get_fdr(int);
+
+static int mpc_reg_in (volatile u32 *reg)
+{
+ int ret = in_be32(reg) >> 24;
+
+ return ret;
+}
+
+static void mpc_reg_out (volatile u32 *reg, int val, int mask)
+{
+ if (!mask) {
+ out_be32(reg, val << 24);
+ } else {
+ clrsetbits_be32(reg, mask << 24, (val & mask) << 24);
+ }
+}
+
+static int wait_for_bb (void)
+{
+ volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
+ volatile i2c512x_dev_t *regs = &im->i2c.dev[bus_num];
+ int timeout = I2C_TIMEOUT;
+ int status;
+
+ status = mpc_reg_in (&regs->msr);
+
+ while (timeout-- && (status & I2C_BB)) {
+ volatile int temp;
+ mpc_reg_out (&regs->mcr, I2C_STA, I2C_STA);
+ temp = mpc_reg_in (&regs->mdr);
+ mpc_reg_out (&regs->mcr, 0, I2C_STA);
+ mpc_reg_out (&regs->mcr, 0, 0);
+ mpc_reg_out (&regs->mcr, I2C_EN, 0);
+
+ udelay (1000);
+ status = mpc_reg_in (&regs->msr);
+ }
+
+ return (status & I2C_BB);
+}
+
+static int wait_for_pin (int *status)
+{
+ volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
+ volatile i2c512x_dev_t *regs = &im->i2c.dev[bus_num];
+ int timeout = I2C_TIMEOUT;
+
+ *status = mpc_reg_in (&regs->msr);
+
+ while (timeout-- && !(*status & I2C_IF)) {
+ udelay (1000);
+ *status = mpc_reg_in (&regs->msr);
+ }
+
+ if (!(*status & I2C_IF)) {
+ return -1;
+ }
+
+ mpc_reg_out (&regs->msr, 0, I2C_IF);
+
+ return 0;
+}
+
+static int do_address (uchar chip, char rdwr_flag)
+{
+ volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
+ volatile i2c512x_dev_t *regs = &im->i2c.dev[bus_num];
+ int status;
+
+ chip <<= 1;
+
+ if (rdwr_flag) {
+ chip |= 1;
+ }
+
+ mpc_reg_out (&regs->mcr, I2C_TX, I2C_TX);
+ mpc_reg_out (&regs->mdr, chip, 0);
+
+ if (wait_for_pin (&status)) {
+ return -2;
+ }
+
+ if (status & I2C_RXAK) {
+ return -3;
+ }
+
+ return 0;
+}
+
+static int send_bytes (uchar chip, char *buf, int len)
+{
+ volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
+ volatile i2c512x_dev_t *regs = &im->i2c.dev[bus_num];
+ int wrcount;
+ int status;
+
+ for (wrcount = 0; wrcount < len; ++wrcount) {
+
+ mpc_reg_out (&regs->mdr, buf[wrcount], 0);
+
+ if (wait_for_pin (&status)) {
+ break;
+ }
+
+ if (status & I2C_RXAK) {
+ break;
+ }
+
+ }
+
+ return !(wrcount == len);
+}
+
+static int receive_bytes (uchar chip, char *buf, int len)
+{
+ volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
+ volatile i2c512x_dev_t *regs = &im->i2c.dev[bus_num];
+ int dummy = 1;
+ int rdcount = 0;
+ int status;
+ int i;
+
+ mpc_reg_out (&regs->mcr, 0, I2C_TX);
+
+ for (i = 0; i < len; ++i) {
+ buf[rdcount] = mpc_reg_in (&regs->mdr);
+
+ if (dummy) {
+ dummy = 0;
+ } else {
+ rdcount++;
+ }
+
+ if (wait_for_pin (&status)) {
+ return -4;
+ }
+ }
+
+ mpc_reg_out (&regs->mcr, I2C_TXAK, I2C_TXAK);
+ buf[rdcount++] = mpc_reg_in (&regs->mdr);
+
+ if (wait_for_pin (&status)) {
+ return -5;
+ }
+
+ mpc_reg_out (&regs->mcr, 0, I2C_TXAK);
+
+ return 0;
+}
+
+/**************** I2C API ****************/
+
+void i2c_init (int speed, int saddr)
+{
+ volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
+ int i;
+
+ for (i = 0; i < I2C_BUS_CNT; i++){
+ volatile i2c512x_dev_t *regs = &im->i2c.dev[i];
+
+ mpc_reg_out (&regs->mcr, 0, 0);
+
+ /* Set clock */
+ mpc_reg_out (&regs->mfdr, mpc_get_fdr (speed), 0);
+ mpc_reg_out (&regs->madr, saddr << 1, 0);
+
+ /* Enable module */
+ mpc_reg_out (&regs->mcr, I2C_EN, I2C_INIT_MASK);
+ mpc_reg_out (&regs->msr, 0, I2C_IF);
+ }
+
+ /* Disable interrupts */
+ out_be32(&im->i2c.icr, 0);
+
+ /* Turn off filters */
+ out_be32(&im->i2c.mifr, 0);
+}
+
+static int mpc_get_fdr (int speed)
+{
+ static int fdr = -1;
+
+ if (fdr == -1) {
+ ulong best_speed = 0;
+ ulong divider;
+ ulong ips, scl;
+ ulong bestmatch = 0xffffffffUL;
+ int best_i = 0, best_j = 0, i, j;
+ int SCL_Tap[] = { 9, 10, 12, 15, 5, 6, 7, 8};
+ struct mpc512x_i2c_tap scltap[] = {
+ {4, 1},
+ {4, 2},
+ {6, 4},
+ {6, 8},
+ {14, 16},
+ {30, 32},
+ {62, 64},
+ {126, 128}
+ };
+
+ ips = gd->ips_clk;
+ for (i = 7; i >= 0; i--) {
+ for (j = 7; j >= 0; j--) {
+ scl = 2 * (scltap[j].scl2tap +
+ (SCL_Tap[i] - 1) * scltap[j].tap2tap
+ + 2);
+ if (ips <= speed*scl) {
+ if ((speed*scl - ips) < bestmatch) {
+ bestmatch = speed*scl - ips;
+ best_i = i;
+ best_j = j;
+ best_speed = ips/scl;
+ }
+ }
+ }
+ }
+ divider = (best_i & 3) | ((best_i & 4) << 3) | (best_j << 2);
+ if (gd->flags & GD_FLG_RELOC) {
+ fdr = divider;
+ } else {
+ debug("%ld kHz, \n", best_speed / 1000);
+ return divider;
+ }
+ }
+
+ return fdr;
+}
+
+int i2c_probe (uchar chip)
+{
+ volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
+ volatile i2c512x_dev_t *regs = &im->i2c.dev[bus_num];
+ int i;
+
+ for (i = 0; i < I2C_RETRIES; i++) {
+ mpc_reg_out (&regs->mcr, I2C_STA, I2C_STA);
+
+ if (! do_address (chip, 0)) {
+ mpc_reg_out (&regs->mcr, 0, I2C_STA);
+ udelay (500);
+ break;
+ }
+
+ mpc_reg_out (&regs->mcr, 0, I2C_STA);
+ udelay (500);
+ }
+
+ return (i == I2C_RETRIES);
+}
+
+int i2c_read (uchar chip, uint addr, int alen, uchar *buf, int len)
+{
+ volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
+ volatile i2c512x_dev_t *regs = &im->i2c.dev[bus_num];
+ char xaddr[4];
+ int ret = -1;
+
+ xaddr[0] = (addr >> 24) & 0xFF;
+ xaddr[1] = (addr >> 16) & 0xFF;
+ xaddr[2] = (addr >> 8) & 0xFF;
+ xaddr[3] = addr & 0xFF;
+
+ if (wait_for_bb ()) {
+ printf ("i2c_read: bus is busy\n");
+ goto Done;
+ }
+
+ mpc_reg_out (&regs->mcr, I2C_STA, I2C_STA);
+ if (do_address (chip, 0)) {
+ printf ("i2c_read: failed to address chip\n");
+ goto Done;
+ }
+
+ if (send_bytes (chip, &xaddr[4-alen], alen)) {
+ printf ("i2c_read: send_bytes failed\n");
+ goto Done;
+ }
+
+ mpc_reg_out (&regs->mcr, I2C_RSTA, I2C_RSTA);
+ if (do_address (chip, 1)) {
+ printf ("i2c_read: failed to address chip\n");
+ goto Done;
+ }
+
+ if (receive_bytes (chip, (char *)buf, len)) {
+ printf ("i2c_read: receive_bytes failed\n");
+ goto Done;
+ }
+
+ ret = 0;
+Done:
+ mpc_reg_out (&regs->mcr, 0, I2C_STA);
+ return ret;
+}
+
+int i2c_write (uchar chip, uint addr, int alen, uchar *buf, int len)
+{
+ volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
+ volatile i2c512x_dev_t *regs = &im->i2c.dev[bus_num];
+ char xaddr[4];
+ int ret = -1;
+
+ xaddr[0] = (addr >> 24) & 0xFF;
+ xaddr[1] = (addr >> 16) & 0xFF;
+ xaddr[2] = (addr >> 8) & 0xFF;
+ xaddr[3] = addr & 0xFF;
+
+ if (wait_for_bb ()) {
+ printf ("i2c_write: bus is busy\n");
+ goto Done;
+ }
+
+ mpc_reg_out (&regs->mcr, I2C_STA, I2C_STA);
+ if (do_address (chip, 0)) {
+ printf ("i2c_write: failed to address chip\n");
+ goto Done;
+ }
+
+ if (send_bytes (chip, &xaddr[4-alen], alen)) {
+ printf ("i2c_write: send_bytes failed\n");
+ goto Done;
+ }
+
+ if (send_bytes (chip, (char *)buf, len)) {
+ printf ("i2c_write: send_bytes failed\n");
+ goto Done;
+ }
+
+ ret = 0;
+Done:
+ mpc_reg_out (&regs->mcr, 0, I2C_STA);
+ return ret;
+}
+
+int i2c_set_bus_num (unsigned int bus)
+{
+ if (bus >= I2C_BUS_CNT) {
+ return -1;
+ }
+ bus_num = bus;
+
+ return 0;
+}
+
+unsigned int i2c_get_bus_num (void)
+{
+ return bus_num;
+}
+
+#endif /* CONFIG_HARD_I2C */
generated by cgit v1.1 at 2024-11-27 22:49:50 +0000