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