--- /dev/null
+/*
+ * (C) Copyright 2003
+ * Gleb Natapov <gnatapov@mrv.com>
+ * Some bits are taken from linux driver writen by adrian@humboldt.co.uk
+ *
+ * Hardware I2C driver for MPC107 PCI bridge.
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+
+#undef I2CDBG
+
+#ifdef CONFIG_HARD_I2C
+#include <i2c.h>
+
+#define TIMEOUT (CONFIG_SYS_HZ/4)
+
+#define I2C_Addr ((unsigned *)(CONFIG_SYS_EUMB_ADDR + 0x3000))
+
+#define I2CADR &I2C_Addr[0]
+#define I2CFDR &I2C_Addr[1]
+#define I2CCCR &I2C_Addr[2]
+#define I2CCSR &I2C_Addr[3]
+#define I2CCDR &I2C_Addr[4]
+
+#define MPC107_CCR_MEN 0x80
+#define MPC107_CCR_MIEN 0x40
+#define MPC107_CCR_MSTA 0x20
+#define MPC107_CCR_MTX 0x10
+#define MPC107_CCR_TXAK 0x08
+#define MPC107_CCR_RSTA 0x04
+
+#define MPC107_CSR_MCF 0x80
+#define MPC107_CSR_MAAS 0x40
+#define MPC107_CSR_MBB 0x20
+#define MPC107_CSR_MAL 0x10
+#define MPC107_CSR_SRW 0x04
+#define MPC107_CSR_MIF 0x02
+#define MPC107_CSR_RXAK 0x01
+
+#define I2C_READ 1
+#define I2C_WRITE 0
+
+/* taken from linux include/asm-ppc/io.h */
+inline unsigned in_le32 (volatile unsigned *addr)
+{
+ unsigned ret;
+
+ __asm__ __volatile__ ("lwbrx %0,0,%1;\n"
+ "twi 0,%0,0;\n"
+ "isync":"=r" (ret): "r" (addr), "m" (*addr));
+ return ret;
+}
+
+inline void out_le32 (volatile unsigned *addr, int val)
+{
+ __asm__ __volatile__ ("stwbrx %1,0,%2; eieio":"=m" (*addr):"r" (val),
+ "r" (addr));
+}
+
+#define writel(val, addr) out_le32(addr, val)
+#define readl(addr) in_le32(addr)
+
+void i2c_init (int speed, int slaveadd)
+{
+ /* stop I2C controller */
+ writel (0x0, I2CCCR);
+ /* set clock */
+ writel (0x1020, I2CFDR);
+ /* write slave address */
+ writel (slaveadd, I2CADR);
+ /* clear status register */
+ writel (0x0, I2CCSR);
+ /* start I2C controller */
+ writel (MPC107_CCR_MEN, I2CCCR);
+
+ return;
+}
+
+static __inline__ int i2c_wait4bus (void)
+{
+ ulong timeval = get_timer (0);
+
+ while (readl (I2CCSR) & MPC107_CSR_MBB)
+ if (get_timer (timeval) > TIMEOUT)
+ return -1;
+
+ return 0;
+}
+
+static __inline__ int i2c_wait (int write)
+{
+ u32 csr;
+ ulong timeval = get_timer (0);
+
+ do {
+ csr = readl (I2CCSR);
+
+ if (!(csr & MPC107_CSR_MIF))
+ continue;
+
+ writel (0x0, I2CCSR);
+
+ if (csr & MPC107_CSR_MAL) {
+#ifdef I2CDBG
+ printf ("i2c_wait: MAL\n");
+#endif
+ return -1;
+ }
+
+ if (!(csr & MPC107_CSR_MCF)) {
+#ifdef I2CDBG
+ printf ("i2c_wait: unfinished\n");
+#endif
+ return -1;
+ }
+
+ if (write == I2C_WRITE && (csr & MPC107_CSR_RXAK)) {
+#ifdef I2CDBG
+ printf ("i2c_wait: No RXACK\n");
+#endif
+ return -1;
+ }
+
+ return 0;
+ } while (get_timer (timeval) < TIMEOUT);
+
+#ifdef I2CDBG
+ printf ("i2c_wait: timed out\n");
+#endif
+ return -1;
+}
+
+static __inline__ int i2c_write_addr (u8 dev, u8 dir, int rsta)
+{
+ writel (MPC107_CCR_MEN | MPC107_CCR_MSTA | MPC107_CCR_MTX |
+ (rsta ? MPC107_CCR_RSTA : 0), I2CCCR);
+
+ writel ((dev << 1) | dir, I2CCDR);
+
+ if (i2c_wait (I2C_WRITE) < 0)
+ return 0;
+
+ return 1;
+}
+
+static __inline__ int __i2c_write (u8 * data, int length)
+{
+ int i;
+
+ writel (MPC107_CCR_MEN | MPC107_CCR_MSTA | MPC107_CCR_MTX, I2CCCR);
+
+ for (i = 0; i < length; i++) {
+ writel (data[i], I2CCDR);
+
+ if (i2c_wait (I2C_WRITE) < 0)
+ break;
+ }
+
+ return i;
+}
+
+static __inline__ int __i2c_read (u8 * data, int length)
+{
+ int i;
+
+ writel (MPC107_CCR_MEN | MPC107_CCR_MSTA |
+ ((length == 1) ? MPC107_CCR_TXAK : 0), I2CCCR);
+
+ /* dummy read */
+ readl (I2CCDR);
+
+ for (i = 0; i < length; i++) {
+ if (i2c_wait (I2C_READ) < 0)
+ break;
+
+ /* Generate ack on last next to last byte */
+ if (i == length - 2)
+ writel (MPC107_CCR_MEN | MPC107_CCR_MSTA |
+ MPC107_CCR_TXAK, I2CCCR);
+
+ /* Generate stop on last byte */
+ if (i == length - 1)
+ writel (MPC107_CCR_MEN | MPC107_CCR_TXAK, I2CCCR);
+
+ data[i] = readl (I2CCDR);
+ }
+
+ return i;
+}
+
+int i2c_read (u8 dev, uint addr, int alen, u8 * data, int length)
+{
+ int i = 0;
+ u8 *a = (u8 *) & addr;
+
+ if (i2c_wait4bus () < 0)
+ goto exit;
+
+ if (i2c_write_addr (dev, I2C_WRITE, 0) == 0)
+ goto exit;
+
+ if (__i2c_write (&a[4 - alen], alen) != alen)
+ goto exit;
+
+ if (i2c_write_addr (dev, I2C_READ, 1) == 0)
+ goto exit;
+
+ i = __i2c_read (data, length);
+
+exit:
+ writel (MPC107_CCR_MEN, I2CCCR);
+
+ return !(i == length);
+}
+
+int i2c_write (u8 dev, uint addr, int alen, u8 * data, int length)
+{
+ int i = 0;
+ u8 *a = (u8 *) & addr;
+
+ if (i2c_wait4bus () < 0)
+ goto exit;
+
+ if (i2c_write_addr (dev, I2C_WRITE, 0) == 0)
+ goto exit;
+
+ if (__i2c_write (&a[4 - alen], alen) != alen)
+ goto exit;
+
+ i = __i2c_write (data, length);
+
+exit:
+ writel (MPC107_CCR_MEN, I2CCCR);
+
+ return !(i == length);
+}
+
+int i2c_probe (uchar chip)
+{
+ int tmp;
+
+ /*
+ * Try to read the first location of the chip. The underlying
+ * driver doesn't appear to support sending just the chip address
+ * and looking for an <ACK> back.
+ */
+ udelay (10000);
+ return i2c_read (chip, 0, 1, (uchar *) &tmp, 1);
+}
+
+#endif /* CONFIG_HARD_I2C */
Code Review / kvmfornfv.git / blobdiff