--- /dev/null
+/*
+ * Driver for the Zynq-7000 PS I2C controller
+ * IP from Cadence (ID T-CS-PE-0007-100, Version R1p10f2)
+ *
+ * Author: Joe Hershberger <joe.hershberger@ni.com>
+ * Copyright (c) 2012 Joe Hershberger.
+ *
+ * Copyright (c) 2012-2013 Xilinx, Michal Simek
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <i2c.h>
+#include <asm/errno.h>
+#include <asm/arch/hardware.h>
+
+/* i2c register set */
+struct zynq_i2c_registers {
+ u32 control;
+ u32 status;
+ u32 address;
+ u32 data;
+ u32 interrupt_status;
+ u32 transfer_size;
+ u32 slave_mon_pause;
+ u32 time_out;
+ u32 interrupt_mask;
+ u32 interrupt_enable;
+ u32 interrupt_disable;
+};
+
+/* Control register fields */
+#define ZYNQ_I2C_CONTROL_RW 0x00000001
+#define ZYNQ_I2C_CONTROL_MS 0x00000002
+#define ZYNQ_I2C_CONTROL_NEA 0x00000004
+#define ZYNQ_I2C_CONTROL_ACKEN 0x00000008
+#define ZYNQ_I2C_CONTROL_HOLD 0x00000010
+#define ZYNQ_I2C_CONTROL_SLVMON 0x00000020
+#define ZYNQ_I2C_CONTROL_CLR_FIFO 0x00000040
+#define ZYNQ_I2C_CONTROL_DIV_B_SHIFT 8
+#define ZYNQ_I2C_CONTROL_DIV_B_MASK 0x00003F00
+#define ZYNQ_I2C_CONTROL_DIV_A_SHIFT 14
+#define ZYNQ_I2C_CONTROL_DIV_A_MASK 0x0000C000
+
+/* Status register values */
+#define ZYNQ_I2C_STATUS_RXDV 0x00000020
+#define ZYNQ_I2C_STATUS_TXDV 0x00000040
+#define ZYNQ_I2C_STATUS_RXOVF 0x00000080
+#define ZYNQ_I2C_STATUS_BA 0x00000100
+
+/* Interrupt register fields */
+#define ZYNQ_I2C_INTERRUPT_COMP 0x00000001
+#define ZYNQ_I2C_INTERRUPT_DATA 0x00000002
+#define ZYNQ_I2C_INTERRUPT_NACK 0x00000004
+#define ZYNQ_I2C_INTERRUPT_TO 0x00000008
+#define ZYNQ_I2C_INTERRUPT_SLVRDY 0x00000010
+#define ZYNQ_I2C_INTERRUPT_RXOVF 0x00000020
+#define ZYNQ_I2C_INTERRUPT_TXOVF 0x00000040
+#define ZYNQ_I2C_INTERRUPT_RXUNF 0x00000080
+#define ZYNQ_I2C_INTERRUPT_ARBLOST 0x00000200
+
+#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;
+
+/* I2C init called by cmd_i2c when doing 'i2c reset'. */
+void i2c_init(int requested_speed, int slaveadd)
+{
+ /* 111MHz / ( (3 * 17) * 22 ) = ~100KHz */
+ writel((16 << ZYNQ_I2C_CONTROL_DIV_B_SHIFT) |
+ (2 << ZYNQ_I2C_CONTROL_DIV_A_SHIFT), &zynq_i2c->control);
+
+ /* Enable master mode, ack, and 7-bit addressing */
+ setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_MS |
+ ZYNQ_I2C_CONTROL_ACKEN | ZYNQ_I2C_CONTROL_NEA);
+}
+
+#ifdef DEBUG
+static void zynq_i2c_debug_status(void)
+{
+ int int_status;
+ int status;
+ int_status = readl(&zynq_i2c->interrupt_status);
+
+ status = readl(&zynq_i2c->status);
+ if (int_status || status) {
+ debug("Status: ");
+ if (int_status & ZYNQ_I2C_INTERRUPT_COMP)
+ debug("COMP ");
+ if (int_status & ZYNQ_I2C_INTERRUPT_DATA)
+ debug("DATA ");
+ if (int_status & ZYNQ_I2C_INTERRUPT_NACK)
+ debug("NACK ");
+ if (int_status & ZYNQ_I2C_INTERRUPT_TO)
+ debug("TO ");
+ if (int_status & ZYNQ_I2C_INTERRUPT_SLVRDY)
+ debug("SLVRDY ");
+ if (int_status & ZYNQ_I2C_INTERRUPT_RXOVF)
+ debug("RXOVF ");
+ if (int_status & ZYNQ_I2C_INTERRUPT_TXOVF)
+ debug("TXOVF ");
+ if (int_status & ZYNQ_I2C_INTERRUPT_RXUNF)
+ debug("RXUNF ");
+ if (int_status & ZYNQ_I2C_INTERRUPT_ARBLOST)
+ debug("ARBLOST ");
+ if (status & ZYNQ_I2C_STATUS_RXDV)
+ debug("RXDV ");
+ if (status & ZYNQ_I2C_STATUS_TXDV)
+ debug("TXDV ");
+ if (status & ZYNQ_I2C_STATUS_RXOVF)
+ debug("RXOVF ");
+ if (status & ZYNQ_I2C_STATUS_BA)
+ debug("BA ");
+ debug("TS%d ", readl(&zynq_i2c->transfer_size));
+ debug("\n");
+ }
+}
+#endif
+
+/* Wait for an interrupt */
+static u32 zynq_i2c_wait(u32 mask)
+{
+ int timeout, int_status;
+
+ for (timeout = 0; timeout < 100; timeout++) {
+ udelay(100);
+ int_status = readl(&zynq_i2c->interrupt_status);
+ if (int_status & mask)
+ break;
+ }
+#ifdef DEBUG
+ zynq_i2c_debug_status();
+#endif
+ /* Clear interrupt status flags */
+ writel(int_status & mask, &zynq_i2c->interrupt_status);
+
+ return int_status & mask;
+}
+
+/*
+ * I2C probe called by cmd_i2c when doing 'i2c probe'.
+ * Begin read, nak data byte, end.
+ */
+int i2c_probe(u8 dev)
+{
+ /* 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(1, &zynq_i2c->transfer_size);
+
+ return (zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP |
+ ZYNQ_I2C_INTERRUPT_NACK) &
+ ZYNQ_I2C_INTERRUPT_COMP) ? 0 : -ETIMEDOUT;
+}
+
+/*
+ * 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)
+{
+ u32 status;
+ u32 i = 0;
+ u8 *cur_data = data;
+
+ /* Check the hardware can handle the requested bytes */
+ if ((length < 0) || (length > ZYNQ_I2C_TRANSFERT_SIZE_MAX))
+ return -EINVAL;
+
+ /* Write the register address */
+ setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_CLR_FIFO |
+ ZYNQ_I2C_CONTROL_HOLD);
+ /*
+ * 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);
+ 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;
+ }
+ 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);
+
+ /* Wait for data */
+ do {
+ status = zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP |
+ ZYNQ_I2C_INTERRUPT_DATA);
+ if (!status) {
+ /* Release the bus */
+ clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
+ return -ETIMEDOUT;
+ }
+ debug("Read %d bytes\n",
+ length - readl(&zynq_i2c->transfer_size));
+ for (; i < length - 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();
+#endif
+ return 0;
+}
+
+/*
+ * 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)
+{
+ u8 *cur_data = data;
+
+ /* 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;
+ }
+
+ debug("Device acked address\n");
+ while (length--) {
+ writel(*(cur_data++), &zynq_i2c->data);
+ if (readl(&zynq_i2c->transfer_size) == ZYNQ_I2C_FIFO_DEPTH) {
+ if (!zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP)) {
+ /* Release the bus */
+ clrbits_le32(&zynq_i2c->control,
+ ZYNQ_I2C_CONTROL_HOLD);
+ return -ETIMEDOUT;
+ }
+ }
+ }
+
+ /* 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))
+ return -ETIMEDOUT;
+ return 0;
+}
+
+int i2c_set_bus_num(unsigned int bus)
+{
+ /* Only support bus 0 */
+ if (bus > 0)
+ return -1;
+ return 0;
+}
+
+unsigned int i2c_get_bus_num(void)
+{
+ /* Only support bus 0 */
+ return 0;
+}
projects / platform / kernel / u-boot.git / commitdiff