[U-Boot] [PATCH] i2c:zynq: I2C multi-bus support on Zynq
Michael Burr
michael.burr at logicpd.com
Fri Sep 20 22:40:43 CEST 2013
Changes:
'zynq_i2c.c':
Adapted driver for compliance with "new" I2C driver model
(CONFIG_SYS_I2C).
Support for 0-length register address in 'i2c_write', 'i2c_read'.
'i2c.h', 'i2c_core.c':
Support for Texas Instruments PCA9548 bus multiplexer.
Tested:
Xilinx ZC702 eval board (single bus master 'I2C0' with multiplexer
PCA9548).
Write and read registers with addresses of length 0 and 1.
Note:
Mainline code does not work "out of the box" on ZC702 at this time;
ad hoc adaptations based on 'u-boot-xlnx' repository were needed
in order to test on this board. (Those adapatations are not included
with this patch.)
Signed-off-by: Michael Burr <michael.burr at logicpd.com>
Cc: Heiko Schocher <hs at denx.de>
Cc: Michal Simek <monstr at monstr.eu>
---
drivers/i2c/i2c_core.c | 5 ++
drivers/i2c/zynq_i2c.c | 148 +++++++++++++++++++++++++++++-------------------
include/i2c.h | 3 +
3 files changed, 97 insertions(+), 59 deletions(-)
diff --git a/drivers/i2c/i2c_core.c b/drivers/i2c/i2c_core.c
index d1072e8..b263562 100644
--- a/drivers/i2c/i2c_core.c
+++ b/drivers/i2c/i2c_core.c
@@ -138,6 +138,11 @@ static int i2c_mux_set(struct i2c_adapter *adap, int mux_id, int chip,
return -1;
buf = (uint8_t)((channel & 0x07) | (1 << 3));
break;
+ case I2C_MUX_PCA9548_ID:
+ if (channel > 7)
+ return -1;
+ buf = (uint8_t)(0x01 << channel);
+ break;
default:
printf("%s: wrong mux id: %d\n", __func__, mux_id);
return -1;
diff --git a/drivers/i2c/zynq_i2c.c b/drivers/i2c/zynq_i2c.c
index ce2d23f..be27966 100644
--- a/drivers/i2c/zynq_i2c.c
+++ b/drivers/i2c/zynq_i2c.c
@@ -7,6 +7,8 @@
*
* Copyright (c) 2012-2013 Xilinx, Michal Simek
*
+ * Copyright (c) 2013 Logic PD, Michael Burr
+ *
* SPDX-License-Identifier: GPL-2.0+
*/
@@ -64,18 +66,28 @@ struct zynq_i2c_registers {
#define ZYNQ_I2C_FIFO_DEPTH 16
#define ZYNQ_I2C_TRANSFERT_SIZE_MAX 255 /* Controller transfer limit */
-#if defined(CONFIG_ZYNQ_I2C0)
-# define ZYNQ_I2C_BASE ZYNQ_I2C_BASEADDR0
-#else
-# define ZYNQ_I2C_BASE ZYNQ_I2C_BASEADDR1
-#endif
-
-static struct zynq_i2c_registers *zynq_i2c =
- (struct zynq_i2c_registers *)ZYNQ_I2C_BASE;
+static struct zynq_i2c_registers *i2c_select(struct i2c_adapter *adap)
+{
+ return adap->hwadapnr ?
+ /* Zynq PS I2C1 */
+ (struct zynq_i2c_registers *)ZYNQ_I2C_BASEADDR1 :
+ /* Zynq PS I2C0 */
+ (struct zynq_i2c_registers *)ZYNQ_I2C_BASEADDR0;
+}
/* I2C init called by cmd_i2c when doing 'i2c reset'. */
-void i2c_init(int requested_speed, int slaveadd)
+static void zynq_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
{
+ struct zynq_i2c_registers *zynq_i2c = i2c_select(adap);
+
+ if (speed != 100000)
+ debug("Warning: requested speed not supported.\n");
+ if (slaveaddr)
+ debug("Warning: slave mode not supported.\n");
+
+ /* The following _assumes_ clock rate cpu_1x = 111 MHz */
+ /* This could use improvement! Also see 'i2c_set_bus_speed' below */
+
/* 111MHz / ( (3 * 17) * 22 ) = ~100KHz */
writel((16 << ZYNQ_I2C_CONTROL_DIV_B_SHIFT) |
(2 << ZYNQ_I2C_CONTROL_DIV_A_SHIFT), &zynq_i2c->control);
@@ -86,7 +98,7 @@ void i2c_init(int requested_speed, int slaveadd)
}
#ifdef DEBUG
-static void zynq_i2c_debug_status(void)
+static void zynq_i2c_debug_status(struct zynq_i2c_registers *zynq_i2c)
{
int int_status;
int status;
@@ -128,7 +140,7 @@ static void zynq_i2c_debug_status(void)
#endif
/* Wait for an interrupt */
-static u32 zynq_i2c_wait(u32 mask)
+static u32 zynq_i2c_wait(struct zynq_i2c_registers *zynq_i2c, u32 mask)
{
int timeout, int_status;
@@ -139,7 +151,7 @@ static u32 zynq_i2c_wait(u32 mask)
break;
}
#ifdef DEBUG
- zynq_i2c_debug_status();
+ zynq_i2c_debug_status(zynq_i2c);
#endif
/* Clear interrupt status flags */
writel(int_status & mask, &zynq_i2c->interrupt_status);
@@ -151,17 +163,19 @@ static u32 zynq_i2c_wait(u32 mask)
* I2C probe called by cmd_i2c when doing 'i2c probe'.
* Begin read, nak data byte, end.
*/
-int i2c_probe(u8 dev)
+static int zynq_i2c_probe(struct i2c_adapter *adap, uint8_t chip)
{
+ struct zynq_i2c_registers *zynq_i2c = i2c_select(adap);
+
/* Attempt to read a byte */
setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_CLR_FIFO |
ZYNQ_I2C_CONTROL_RW);
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
writel(0xFF, &zynq_i2c->interrupt_status);
- writel(dev, &zynq_i2c->address);
+ writel(chip, &zynq_i2c->address);
writel(1, &zynq_i2c->transfer_size);
- return (zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP |
+ return (zynq_i2c_wait(zynq_i2c, ZYNQ_I2C_INTERRUPT_COMP |
ZYNQ_I2C_INTERRUPT_NACK) &
ZYNQ_I2C_INTERRUPT_COMP) ? 0 : -ETIMEDOUT;
}
@@ -170,14 +184,18 @@ int i2c_probe(u8 dev)
* I2C read called by cmd_i2c when doing 'i2c read' and by cmd_eeprom.c
* Begin write, send address byte(s), begin read, receive data bytes, end.
*/
-int i2c_read(u8 dev, uint addr, int alen, u8 *data, int length)
+static int zynq_i2c_read(struct i2c_adapter *adap, uint8_t chip, uint addr,
+ int alen, uint8_t *buffer, int len)
{
+ struct zynq_i2c_registers *zynq_i2c;
u32 status;
u32 i = 0;
- u8 *cur_data = data;
+ u8 *cur_data = buffer;
+
+ zynq_i2c = i2c_select(adap);
/* Check the hardware can handle the requested bytes */
- if ((length < 0) || (length > ZYNQ_I2C_TRANSFERT_SIZE_MAX))
+ if ((len < 0) || (len > ZYNQ_I2C_TRANSFERT_SIZE_MAX))
return -EINVAL;
/* Write the register address */
@@ -187,30 +205,33 @@ int i2c_read(u8 dev, uint addr, int alen, u8 *data, int length)
* Temporarily disable restart (by clearing hold)
* It doesn't seem to work.
*/
- clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_RW |
- ZYNQ_I2C_CONTROL_HOLD);
+ clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
+
writel(0xFF, &zynq_i2c->interrupt_status);
- while (alen--)
- writel(addr >> (8*alen), &zynq_i2c->data);
- writel(dev, &zynq_i2c->address);
-
- /* Wait for the address to be sent */
- if (!zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP)) {
- /* Release the bus */
- clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
- return -ETIMEDOUT;
+ if (alen) {
+ clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_RW);
+ writel(chip, &zynq_i2c->address);
+ while (alen--)
+ writel(addr >> (8*alen), &zynq_i2c->data);
+
+ /* Wait for the address to be sent */
+ if (!zynq_i2c_wait(zynq_i2c, ZYNQ_I2C_INTERRUPT_COMP)) {
+ /* Release the bus */
+ clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
+ return -ETIMEDOUT;
+ }
+ debug("Device acked address\n");
}
- debug("Device acked address\n");
setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_CLR_FIFO |
ZYNQ_I2C_CONTROL_RW);
/* Start reading data */
- writel(dev, &zynq_i2c->address);
- writel(length, &zynq_i2c->transfer_size);
+ writel(len, &zynq_i2c->transfer_size);
+ writel(chip, &zynq_i2c->address);
/* Wait for data */
do {
- status = zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP |
+ status = zynq_i2c_wait(zynq_i2c, ZYNQ_I2C_INTERRUPT_COMP |
ZYNQ_I2C_INTERRUPT_DATA);
if (!status) {
/* Release the bus */
@@ -218,15 +239,15 @@ int i2c_read(u8 dev, uint addr, int alen, u8 *data, int length)
return -ETIMEDOUT;
}
debug("Read %d bytes\n",
- length - readl(&zynq_i2c->transfer_size));
- for (; i < length - readl(&zynq_i2c->transfer_size); i++)
+ len - readl(&zynq_i2c->transfer_size));
+ for (; i < len - readl(&zynq_i2c->transfer_size); i++)
*(cur_data++) = readl(&zynq_i2c->data);
} while (readl(&zynq_i2c->transfer_size) != 0);
/* All done... release the bus */
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
#ifdef DEBUG
- zynq_i2c_debug_status();
+ zynq_i2c_debug_status(zynq_i2c);
#endif
return 0;
}
@@ -235,30 +256,35 @@ int i2c_read(u8 dev, uint addr, int alen, u8 *data, int length)
* I2C write called by cmd_i2c when doing 'i2c write' and by cmd_eeprom.c
* Begin write, send address byte(s), send data bytes, end.
*/
-int i2c_write(u8 dev, uint addr, int alen, u8 *data, int length)
+static int zynq_i2c_write(struct i2c_adapter *adap, uint8_t chip, uint addr,
+ int alen, uint8_t *buffer, int len)
{
- u8 *cur_data = data;
+ struct zynq_i2c_registers *zynq_i2c;
+ u8 *cur_data = buffer;
+
+ zynq_i2c = i2c_select(adap);
/* Write the register address */
setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_CLR_FIFO |
ZYNQ_I2C_CONTROL_HOLD);
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_RW);
writel(0xFF, &zynq_i2c->interrupt_status);
- while (alen--)
- writel(addr >> (8*alen), &zynq_i2c->data);
- /* Start the tranfer */
- writel(dev, &zynq_i2c->address);
- if (!zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP)) {
- /* Release the bus */
- clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
- return -ETIMEDOUT;
+ writel(chip, &zynq_i2c->address);
+ if (alen) {
+ while (alen--)
+ writel(addr >> (8*alen), &zynq_i2c->data);
+ /* Start the tranfer */
+ if (!zynq_i2c_wait(zynq_i2c, ZYNQ_I2C_INTERRUPT_COMP)) {
+ /* Release the bus */
+ clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
+ return -ETIMEDOUT;
+ }
+ debug("Device acked address\n");
}
-
- debug("Device acked address\n");
- while (length--) {
+ while (len--) {
writel(*(cur_data++), &zynq_i2c->data);
if (readl(&zynq_i2c->transfer_size) == ZYNQ_I2C_FIFO_DEPTH) {
- if (!zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP)) {
+ if (!zynq_i2c_wait(zynq_i2c, ZYNQ_I2C_INTERRUPT_COMP)) {
/* Release the bus */
clrbits_le32(&zynq_i2c->control,
ZYNQ_I2C_CONTROL_HOLD);
@@ -270,21 +296,25 @@ int i2c_write(u8 dev, uint addr, int alen, u8 *data, int length)
/* All done... release the bus */
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
/* Wait for the address and data to be sent */
- if (!zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP))
+ if (!zynq_i2c_wait(zynq_i2c, ZYNQ_I2C_INTERRUPT_COMP))
return -ETIMEDOUT;
return 0;
}
-int i2c_set_bus_num(unsigned int bus)
+static uint zynq_i2c_set_bus_speed(struct i2c_adapter *adap, uint speed)
{
- /* Only support bus 0 */
- if (bus > 0)
+ /* struct zynq_i2c_registers *zynq_i2c = i2c_select(adap); */
+
+ /* Bus-speed selection is not implemented */
+ if (speed != 100000)
return -1;
- return 0;
-}
-unsigned int i2c_get_bus_num(void)
-{
- /* Only support bus 0 */
return 0;
}
+
+U_BOOT_I2C_ADAP_COMPLETE(ZYNQ_I2C0, zynq_i2c_init, zynq_i2c_probe,
+ zynq_i2c_read, zynq_i2c_write,
+ zynq_i2c_set_bus_speed, 100000, 0, 0)
+U_BOOT_I2C_ADAP_COMPLETE(ZYNQ_I2C1, zynq_i2c_init, zynq_i2c_probe,
+ zynq_i2c_read, zynq_i2c_write,
+ zynq_i2c_set_bus_speed, 100000, 0, 1)
diff --git a/include/i2c.h b/include/i2c.h
index 8fd17d1..683affe 100644
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -40,6 +40,7 @@
#define CONFIG_SYS_I2C_MAX_HOPS 0
#define CONFIG_SYS_NUM_I2C_BUSES ll_entry_count(struct i2c_adapter, i2c)
#else
+
/* we use i2c muxes */
#undef CONFIG_SYS_I2C_DIRECT_BUS
#endif
@@ -135,6 +136,8 @@ extern struct i2c_bus_hose i2c_bus[];
#define I2C_MUX_PCA9544 {I2C_MUX_PCA9544_ID, "PCA9544A"}
#define I2C_MUX_PCA9547_ID 4
#define I2C_MUX_PCA9547 {I2C_MUX_PCA9547_ID, "PCA9547A"}
+#define I2C_MUX_PCA9548_ID 5
+#define I2C_MUX_PCA9548 {I2C_MUX_PCA9548_ID, "PCA9548"}
#endif
#ifndef I2C_SOFT_DECLARATIONS
--
1.7.9.5
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