[U-Boot] [PATCH v8 2/2] I2C: Zynq: Adapt this driver to the new model

Michael Burr
2013-10-15T20:23:14Z

Driver 'zynq_i2c.c' together with CONFIGs, README,
and Makefile.

Signed-off-by: Michael Burr <michael.burr@logicpd.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Michal Simek <monstr@monstr.eu>

---
Note: the changes to file 'zynq_i2c.c' in this patch series are
meant to be applied in order: in other words, first apply the
changes from the 1/2 version; then apply the changes in the 2/2
version.

Tested on Xilinx ZC702 eval board:
Select various I2C chips using TI PCA9548 bus multiplexer.
Write and read registers with addresses of length 0 and 1.

---
README | 9 ++++
drivers/i2c/Makefile | 2 +-
drivers/i2c/zynq_i2c.c | 108
++++++++++++++++++++++++++++++------------------
include/configs/zynq.h | 10 ++---
4 files changed, 81 insertions(+), 48 deletions(-)

diff --git a/README b/README
index ccd47fa..fd2c8fc 100644
--- a/README
+++ b/README
@@ -1995,6 +1995,15 @@ CBFS (Coreboot Filesystem) support
- CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
- CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1

+ - drivers/i2c/zynq_i2c.c
+ - Activate this driver with CONFIG_SYS_I2C_ZYNQ
+ - This driver operates only as bus-master (i.e. slave-
+ address == 0) and supports only 100 kbps speed.
+ - Both bus-controller devices in the Zynq PS (I2C0 and I2C1)
+ are supported. (However, note that Zynq PL configuration
+ may be needed in order to route some bus lines to external
+ pins.)
+
additional defines:

CONFIG_SYS_NUM_I2C_BUSES
diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index 37ccbd1..55ce32d 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -32,7 +32,7 @@ COBJS-$(CONFIG_SYS_I2C_FTI2C010) += fti2c010.o
COBJS-$(CONFIG_SYS_I2C_PPC4XX) += ppc4xx_i2c.o
COBJS-$(CONFIG_SYS_I2C_SOFT) += soft_i2c.o
COBJS-$(CONFIG_SYS_I2C_TEGRA) += tegra_i2c.o
-COBJS-$(CONFIG_ZYNQ_I2C) += zynq_i2c.o
+COBJS-$(CONFIG_SYS_I2C_ZYNQ) += zynq_i2c.o

COBJS := $(COBJS-y)
SRCS := $(COBJS:.o=.c)
diff --git a/drivers/i2c/zynq_i2c.c b/drivers/i2c/zynq_i2c.c
index 9cbd3e4..7972a59 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 */
@@ -191,12 +209,12 @@ int i2c_read(u8 dev, uint addr, int alen, u8
*data, int length)
writel(0xFF, &zynq_i2c->interrupt_status);
if (alen) {
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_RW);
- writel(dev, &zynq_i2c->address);
+ 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_INTERRUPT_COMP)) {
+ if (!zynq_i2c_wait(zynq_i2c, ZYNQ_I2C_INTERRUPT_COMP)) {
/* Release the bus */
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
return -ETIMEDOUT;
@@ -207,12 +225,12 @@ int i2c_read(u8 dev, uint addr, int alen, u8
*data, int length)
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 */
@@ -220,15 +238,15 @@ 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;
}
@@ -237,31 +255,35 @@ 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);
- writel(dev, &zynq_i2c->address);
+ 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_INTERRUPT_COMP)) {
+ 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");
}
- 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);
@@ -273,21 +295,25 @@ 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/configs/zynq.h b/include/configs/zynq.h
index b9f381f..1ae915f 100644
--- a/include/configs/zynq.h
+++ b/include/configs/zynq.h
@@ -56,15 +56,13 @@
# define CONFIG_DOS_PARTITION
#endif

-#define CONFIG_ZYNQ_I2C0
-
/* I2C */
-#if defined(CONFIG_ZYNQ_I2C0) || defined(CONFIG_ZYNQ_I2C1)
+#define CONFIG_SYS_I2C_ZYNQ
+#ifdef CONFIG_SYS_I2C_ZYNQ
+# define CONFIG_SYS_I2C
# define CONFIG_CMD_I2C
-# define CONFIG_ZYNQ_I2C
-# define CONFIG_HARD_I2C
# define CONFIG_SYS_I2C_SPEED 100000
-# define CONFIG_SYS_I2C_SLAVE 1
+# define CONFIG_SYS_I2C_SLAVE 0
#endif

#if defined(CONFIG_ZYNQ_DCC)
--
1.7.9.5