designware_i2c: remove 10msec delay in i2c_xfer_finish

[people/ms/u-boot.git] / drivers / i2c / designware_i2c.c

diff --git a/drivers/i2c/designware_i2c.c b/drivers/i2c/designware_i2c.c
index 4e4bfd4f57d952eb93f6f664db6833b58a046517..cb2ac04b609864412a8054888f3420bf35ca0287 100644 (file)
--- a/drivers/i2c/designware_i2c.c
+++ b/drivers/i2c/designware_i2c.c
@@ -2,23 +2,7 @@
  * (C) Copyright 2009
  * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.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
+ * SPDX-License-Identifier:    GPL-2.0+
  */
 
 #include <common.h>
@@ -44,7 +28,6 @@ static void set_speed(int i2c_spd)
 {
        unsigned int cntl;
        unsigned int hcnt, lcnt;
-       unsigned int high, low;
        unsigned int enbl;
 
        /* to set speed cltr must be disabled */
@@ -52,39 +35,38 @@ static void set_speed(int i2c_spd)
        enbl &= ~IC_ENABLE_0B;
        writel(enbl, &i2c_regs_p->ic_enable);
 
-
        cntl = (readl(&i2c_regs_p->ic_con) & (~IC_CON_SPD_MSK));
 
        switch (i2c_spd) {
        case IC_SPEED_MODE_MAX:
                cntl |= IC_CON_SPD_HS;
-               high = MIN_HS_SCL_HIGHTIME;
-               low = MIN_HS_SCL_LOWTIME;
+               hcnt = (IC_CLK * MIN_HS_SCL_HIGHTIME) / NANO_TO_MICRO;
+               writel(hcnt, &i2c_regs_p->ic_hs_scl_hcnt);
+               lcnt = (IC_CLK * MIN_HS_SCL_LOWTIME) / NANO_TO_MICRO;
+               writel(lcnt, &i2c_regs_p->ic_hs_scl_lcnt);
                break;
 
        case IC_SPEED_MODE_STANDARD:
                cntl |= IC_CON_SPD_SS;
-               high = MIN_SS_SCL_HIGHTIME;
-               low = MIN_SS_SCL_LOWTIME;
+               hcnt = (IC_CLK * MIN_SS_SCL_HIGHTIME) / NANO_TO_MICRO;
+               writel(hcnt, &i2c_regs_p->ic_ss_scl_hcnt);
+               lcnt = (IC_CLK * MIN_SS_SCL_LOWTIME) / NANO_TO_MICRO;
+               writel(lcnt, &i2c_regs_p->ic_ss_scl_lcnt);
                break;
 
        case IC_SPEED_MODE_FAST:
        default:
                cntl |= IC_CON_SPD_FS;
-               high = MIN_FS_SCL_HIGHTIME;
-               low = MIN_FS_SCL_LOWTIME;
+               hcnt = (IC_CLK * MIN_FS_SCL_HIGHTIME) / NANO_TO_MICRO;
+               writel(hcnt, &i2c_regs_p->ic_fs_scl_hcnt);
+               lcnt = (IC_CLK * MIN_FS_SCL_LOWTIME) / NANO_TO_MICRO;
+               writel(lcnt, &i2c_regs_p->ic_fs_scl_lcnt);
                break;
        }
 
        writel(cntl, &i2c_regs_p->ic_con);
 
-       hcnt = (IC_CLK * high) / NANO_TO_MICRO;
-       writel(hcnt, &i2c_regs_p->ic_fs_scl_hcnt);
-
-       lcnt = (IC_CLK * low) / NANO_TO_MICRO;
-       writel(lcnt, &i2c_regs_p->ic_fs_scl_lcnt);
-
-       /* re-enable i2c ctrl back now that speed is set */
+       /* Enable back i2c now speed set */
        enbl |= IC_ENABLE_0B;
        writel(enbl, &i2c_regs_p->ic_enable);
 }
@@ -169,7 +151,19 @@ void i2c_init(int speed, int slaveadd)
  */
 static void i2c_setaddress(unsigned int i2c_addr)
 {
+       unsigned int enbl;
+
+       /* Disable i2c */
+       enbl = readl(&i2c_regs_p->ic_enable);
+       enbl &= ~IC_ENABLE_0B;
+       writel(enbl, &i2c_regs_p->ic_enable);
+
        writel(i2c_addr, &i2c_regs_p->ic_tar);
+
+       /* Enable i2c */
+       enbl = readl(&i2c_regs_p->ic_enable);
+       enbl |= IC_ENABLE_0B;
+       writel(enbl, &i2c_regs_p->ic_enable);
 }
 
 /*
@@ -255,9 +249,6 @@ static int i2c_xfer_finish(void)
 
        i2c_flush_rxfifo();
 
-       /* Wait for read/write operation to complete on actual memory */
-       udelay(10000);
-
        return 0;
 }
 
@@ -283,7 +274,10 @@ int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
 
        start_time_rx = get_timer(0);
        while (len) {
-               writel(IC_CMD, &i2c_regs_p->ic_cmd_data);
+               if (len == 1)
+                       writel(IC_CMD | IC_STOP, &i2c_regs_p->ic_cmd_data);
+               else
+                       writel(IC_CMD, &i2c_regs_p->ic_cmd_data);
 
                if (readl(&i2c_regs_p->ic_status) & IC_STATUS_RFNE) {
                        *buffer++ = (uchar)readl(&i2c_regs_p->ic_cmd_data);
@@ -322,9 +316,11 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
        start_time_tx = get_timer(0);
        while (len) {
                if (readl(&i2c_regs_p->ic_status) & IC_STATUS_TFNF) {
-                       writel(*buffer, &i2c_regs_p->ic_cmd_data);
+                       if (--len == 0)
+                               writel(*buffer | IC_STOP, &i2c_regs_p->ic_cmd_data);
+                       else
+                               writel(*buffer, &i2c_regs_p->ic_cmd_data);
                        buffer++;
-                       len--;
                        start_time_tx = get_timer(0);
 
                } else if (get_timer(start_time_tx) > (nb * I2C_BYTE_TO)) {