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authorStefan Roese <sr@denx.de>2010-04-15 16:07:28 +0200
committerWolfgang Denk <wd@denx.de>2010-04-21 23:42:38 +0200
commita47a12becf66f02a56da91c161e2edb625e9f20c (patch)
tree6efae7137d26d1e610c5fd56b7aaa3c043ad2b71 /arch/powerpc/cpu/mpc8220/i2c.c
parent254ab7bd464657600aba69d840406f9358f3e116 (diff)
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Move arch/ppc to arch/powerpc
As discussed on the list, move "arch/ppc" to "arch/powerpc" to better match the Linux directory structure. Please note that this patch also changes the "ppc" target in MAKEALL to "powerpc" to match this new infrastructure. But "ppc" is kept as an alias for now, to not break compatibility with scripts using this name. Signed-off-by: Stefan Roese <sr@denx.de> Acked-by: Wolfgang Denk <wd@denx.de> Acked-by: Detlev Zundel <dzu@denx.de> Acked-by: Kim Phillips <kim.phillips@freescale.com> Cc: Peter Tyser <ptyser@xes-inc.com> Cc: Anatolij Gustschin <agust@denx.de>
Diffstat (limited to 'arch/powerpc/cpu/mpc8220/i2c.c')
-rw-r--r--arch/powerpc/cpu/mpc8220/i2c.c390
1 files changed, 390 insertions, 0 deletions
diff --git a/arch/powerpc/cpu/mpc8220/i2c.c b/arch/powerpc/cpu/mpc8220/i2c.c
new file mode 100644
index 0000000..76ecdf1
--- /dev/null
+++ b/arch/powerpc/cpu/mpc8220/i2c.c
@@ -0,0 +1,390 @@
+/*
+ * (C) Copyright 2004, Freescale, Inc
+ * TsiChung Liew, Tsi-Chung.Liew@freescale.com.
+ *
+ * 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
+ */
+
+#include <common.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#ifdef CONFIG_HARD_I2C
+
+#include <mpc8220.h>
+#include <i2c.h>
+
+typedef struct mpc8220_i2c {
+ volatile u32 adr; /* I2Cn + 0x00 */
+ volatile u32 fdr; /* I2Cn + 0x04 */
+ volatile u32 cr; /* I2Cn + 0x08 */
+ volatile u32 sr; /* I2Cn + 0x0C */
+ volatile u32 dr; /* I2Cn + 0x10 */
+} i2c_t;
+
+/* I2Cn control register bits */
+#define I2C_EN 0x80
+#define I2C_IEN 0x40
+#define I2C_STA 0x20
+#define I2C_TX 0x10
+#define I2C_TXAK 0x08
+#define I2C_RSTA 0x04
+#define I2C_INIT_MASK (I2C_EN | I2C_STA | I2C_TX | I2C_RSTA)
+
+/* I2Cn status register bits */
+#define I2C_CF 0x80
+#define I2C_AAS 0x40
+#define I2C_BB 0x20
+#define I2C_AL 0x10
+#define I2C_SRW 0x04
+#define I2C_IF 0x02
+#define I2C_RXAK 0x01
+
+#define I2C_TIMEOUT 100
+#define I2C_RETRIES 1
+
+struct mpc8220_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;
+ ret = *reg >> 24;
+ __asm__ __volatile__ ("eieio");
+ return ret;
+}
+
+static void mpc_reg_out (volatile u32 * reg, int val, int mask)
+{
+ int tmp;
+
+ if (!mask) {
+ *reg = val << 24;
+ } else {
+ tmp = mpc_reg_in (reg);
+ *reg = ((tmp & ~mask) | (val & mask)) << 24;
+ }
+ __asm__ __volatile__ ("eieio");
+
+ return;
+}
+
+static int wait_for_bb (void)
+{
+ i2c_t *regs = (i2c_t *) MMAP_I2C;
+ int timeout = I2C_TIMEOUT;
+ int status;
+
+ status = mpc_reg_in (&regs->sr);
+
+ while (timeout-- && (status & I2C_BB)) {
+#if 1
+ volatile int temp;
+
+ mpc_reg_out (&regs->cr, I2C_STA, I2C_STA);
+ temp = mpc_reg_in (&regs->dr);
+ mpc_reg_out (&regs->cr, 0, I2C_STA);
+ mpc_reg_out (&regs->cr, 0, 0);
+ mpc_reg_out (&regs->cr, I2C_EN, 0);
+#endif
+ udelay (1000);
+ status = mpc_reg_in (&regs->sr);
+ }
+
+ return (status & I2C_BB);
+}
+
+static int wait_for_pin (int *status)
+{
+ i2c_t *regs = (i2c_t *) MMAP_I2C;
+ int timeout = I2C_TIMEOUT;
+
+ *status = mpc_reg_in (&regs->sr);
+
+ while (timeout-- && !(*status & I2C_IF)) {
+ udelay (1000);
+ *status = mpc_reg_in (&regs->sr);
+ }
+
+ if (!(*status & I2C_IF)) {
+ return -1;
+ }
+
+ mpc_reg_out (&regs->sr, 0, I2C_IF);
+ return 0;
+}
+
+static int do_address (uchar chip, char rdwr_flag)
+{
+ i2c_t *regs = (i2c_t *) MMAP_I2C;
+ int status;
+
+ chip <<= 1;
+
+ if (rdwr_flag)
+ chip |= 1;
+
+ mpc_reg_out (&regs->cr, I2C_TX, I2C_TX);
+ mpc_reg_out (&regs->dr, 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)
+{
+ i2c_t *regs = (i2c_t *) MMAP_I2C;
+ int wrcount;
+ int status;
+
+ for (wrcount = 0; wrcount < len; ++wrcount) {
+
+ mpc_reg_out (&regs->dr, buf[wrcount], 0);
+
+ if (wait_for_pin (&status))
+ break;
+
+ if (status & I2C_RXAK)
+ break;
+
+ }
+
+ return !(wrcount == len);
+ return 0;
+}
+
+static int receive_bytes (uchar chip, char *buf, int len)
+{
+ i2c_t *regs = (i2c_t *) MMAP_I2C;
+ int dummy = 1;
+ int rdcount = 0;
+ int status;
+ int i;
+
+ mpc_reg_out (&regs->cr, 0, I2C_TX);
+
+ for (i = 0; i < len; ++i) {
+ buf[rdcount] = mpc_reg_in (&regs->dr);
+
+ if (dummy)
+ dummy = 0;
+ else
+ rdcount++;
+
+ if (wait_for_pin (&status))
+ return -4;
+ }
+
+ mpc_reg_out (&regs->cr, I2C_TXAK, I2C_TXAK);
+ buf[rdcount++] = mpc_reg_in (&regs->dr);
+
+ if (wait_for_pin (&status))
+ return -5;
+
+ mpc_reg_out (&regs->cr, 0, I2C_TXAK);
+ return 0;
+}
+
+/**************** I2C API ****************/
+
+void i2c_init (int speed, int saddr)
+{
+ i2c_t *regs = (i2c_t *) MMAP_I2C;
+
+ mpc_reg_out (&regs->cr, 0, 0);
+ mpc_reg_out (&regs->adr, saddr << 1, 0);
+
+ /* Set clock
+ */
+ mpc_reg_out (&regs->fdr, mpc_get_fdr (speed), 0);
+
+ /* Enable module
+ */
+ mpc_reg_out (&regs->cr, I2C_EN, I2C_INIT_MASK);
+ mpc_reg_out (&regs->sr, 0, I2C_IF);
+ return;
+}
+
+static int mpc_get_fdr (int speed)
+{
+ static int fdr = -1;
+
+ if (fdr == -1) {
+ ulong best_speed = 0;
+ ulong divider;
+ ulong ipb, 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 mpc8220_i2c_tap scltap[] = {
+ {4, 1},
+ {4, 2},
+ {6, 4},
+ {6, 8},
+ {14, 16},
+ {30, 32},
+ {62, 64},
+ {126, 128}
+ };
+
+ ipb = gd->bus_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 (ipb <= speed * scl) {
+ if ((speed * scl - ipb) < bestmatch) {
+ bestmatch = speed * scl - ipb;
+ best_i = i;
+ best_j = j;
+ best_speed = ipb / scl;
+ }
+ }
+ }
+ }
+ divider = (best_i & 3) | ((best_i & 4) << 3) | (best_j << 2);
+ if (gd->flags & GD_FLG_RELOC) {
+ fdr = divider;
+ } else {
+ printf ("%ld kHz, ", best_speed / 1000);
+ return divider;
+ }
+ }
+
+ return fdr;
+}
+
+int i2c_probe (uchar chip)
+{
+ i2c_t *regs = (i2c_t *) MMAP_I2C;
+ int i;
+
+ for (i = 0; i < I2C_RETRIES; i++) {
+ mpc_reg_out (&regs->cr, I2C_STA, I2C_STA);
+
+ if (!do_address (chip, 0)) {
+ mpc_reg_out (&regs->cr, 0, I2C_STA);
+ break;
+ }
+
+ mpc_reg_out (&regs->cr, 0, I2C_STA);
+ udelay (50);
+ }
+
+ return (i == I2C_RETRIES);
+}
+
+int i2c_read (uchar chip, uint addr, int alen, uchar * buf, int len)
+{
+ uchar xaddr[4];
+ i2c_t *regs = (i2c_t *) MMAP_I2C;
+ 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->cr, I2C_STA, I2C_STA);
+ if (do_address (chip, 0)) {
+ printf ("i2c_read: failed to address chip\n");
+ goto Done;
+ }
+
+ if (send_bytes (chip, (char *)&xaddr[4 - alen], alen)) {
+ printf ("i2c_read: send_bytes failed\n");
+ goto Done;
+ }
+
+ mpc_reg_out (&regs->cr, 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->cr, 0, I2C_STA);
+ return ret;
+}
+
+int i2c_write (uchar chip, uint addr, int alen, uchar * buf, int len)
+{
+ uchar xaddr[4];
+ i2c_t *regs = (i2c_t *) MMAP_I2C;
+ 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->cr, I2C_STA, I2C_STA);
+ if (do_address (chip, 0)) {
+ printf ("i2c_write: failed to address chip\n");
+ goto Done;
+ }
+
+ if (send_bytes (chip, (char *)&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->cr, 0, I2C_STA);
+ return ret;
+}
+
+#endif /* CONFIG_HARD_I2C */