diff options
| -rw-r--r-- | Documentation/powerpc/dts-bindings/fsl/i2c.txt | 2 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-mpc.c | 69 |
2 files changed, 49 insertions, 22 deletions
diff --git a/Documentation/powerpc/dts-bindings/fsl/i2c.txt b/Documentation/powerpc/dts-bindings/fsl/i2c.txt index 50da2031058..1eacd6b20ed 100644 --- a/Documentation/powerpc/dts-bindings/fsl/i2c.txt +++ b/Documentation/powerpc/dts-bindings/fsl/i2c.txt @@ -20,6 +20,7 @@ Recommended properties : - fsl,preserve-clocking : boolean; if defined, the clock settings from the bootloader are preserved (not touched). - clock-frequency : desired I2C bus clock frequency in Hz. + - fsl,timeout : I2C bus timeout in microseconds. Examples : @@ -59,4 +60,5 @@ Examples : interrupts = <43 2>; interrupt-parent = <&mpic>; clock-frequency = <400000>; + fsl,timeout = <10000>; }; diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c index df00eb1f11f..54247d475fc 100644 --- a/drivers/i2c/busses/i2c-mpc.c +++ b/drivers/i2c/busses/i2c-mpc.c @@ -63,6 +63,7 @@ struct mpc_i2c { wait_queue_head_t queue; struct i2c_adapter adap; int irq; + u32 real_clk; }; struct mpc_i2c_divider { @@ -96,20 +97,23 @@ static irqreturn_t mpc_i2c_isr(int irq, void *dev_id) /* Sometimes 9th clock pulse isn't generated, and slave doesn't release * the bus, because it wants to send ACK. * Following sequence of enabling/disabling and sending start/stop generates - * the pulse, so it's all OK. + * the 9 pulses, so it's all OK. */ static void mpc_i2c_fixup(struct mpc_i2c *i2c) { - writeccr(i2c, 0); - udelay(30); - writeccr(i2c, CCR_MEN); - udelay(30); - writeccr(i2c, CCR_MSTA | CCR_MTX); - udelay(30); - writeccr(i2c, CCR_MSTA | CCR_MTX | CCR_MEN); - udelay(30); - writeccr(i2c, CCR_MEN); - udelay(30); + int k; + u32 delay_val = 1000000 / i2c->real_clk + 1; + + if (delay_val < 2) + delay_val = 2; + + for (k = 9; k; k--) { + writeccr(i2c, 0); + writeccr(i2c, CCR_MSTA | CCR_MTX | CCR_MEN); + udelay(delay_val); + writeccr(i2c, CCR_MEN); + udelay(delay_val << 1); + } } static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing) @@ -190,15 +194,18 @@ static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] __devinitconst = { }; static int __devinit mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock, - int prescaler) + int prescaler, u32 *real_clk) { const struct mpc_i2c_divider *div = NULL; unsigned int pvr = mfspr(SPRN_PVR); u32 divider; int i; - if (clock == MPC_I2C_CLOCK_LEGACY) + if (clock == MPC_I2C_CLOCK_LEGACY) { + /* see below - default fdr = 0x3f -> div = 2048 */ + *real_clk = mpc5xxx_get_bus_frequency(node) / 2048; return -EINVAL; + } /* Determine divider value */ divider = mpc5xxx_get_bus_frequency(node) / clock; @@ -216,7 +223,8 @@ static int __devinit mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock, break; } - return div ? (int)div->fdr : -EINVAL; + *real_clk = mpc5xxx_get_bus_frequency(node) / div->divider; + return (int)div->fdr; } static void __devinit mpc_i2c_setup_52xx(struct device_node *node, @@ -231,13 +239,14 @@ static void __devinit mpc_i2c_setup_52xx(struct device_node *node, return; } - ret = mpc_i2c_get_fdr_52xx(node, clock, prescaler); + ret = mpc_i2c_get_fdr_52xx(node, clock, prescaler, &i2c->real_clk); fdr = (ret >= 0) ? ret : 0x3f; /* backward compatibility */ writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR); if (ret >= 0) - dev_info(i2c->dev, "clock %d Hz (fdr=%d)\n", clock, fdr); + dev_info(i2c->dev, "clock %u Hz (fdr=%d)\n", i2c->real_clk, + fdr); } #else /* !(CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x) */ static void __devinit mpc_i2c_setup_52xx(struct device_node *node, @@ -334,14 +343,17 @@ static u32 __devinit mpc_i2c_get_sec_cfg_8xxx(void) } static int __devinit mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock, - u32 prescaler) + u32 prescaler, u32 *real_clk) { const struct mpc_i2c_divider *div = NULL; u32 divider; int i; - if (clock == MPC_I2C_CLOCK_LEGACY) + if (clock == MPC_I2C_CLOCK_LEGACY) { + /* see below - default fdr = 0x1031 -> div = 16 * 3072 */ + *real_clk = fsl_get_sys_freq() / prescaler / (16 * 3072); return -EINVAL; + } /* Determine proper divider value */ if (of_device_is_compatible(node, "fsl,mpc8544-i2c")) @@ -364,6 +376,7 @@ static int __devinit mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock, break; } + *real_clk = fsl_get_sys_freq() / prescaler / div->divider; return div ? (int)div->fdr : -EINVAL; } @@ -380,7 +393,7 @@ static void __devinit mpc_i2c_setup_8xxx(struct device_node *node, return; } - ret = mpc_i2c_get_fdr_8xxx(node, clock, prescaler); + ret = mpc_i2c_get_fdr_8xxx(node, clock, prescaler, &i2c->real_clk); fdr = (ret >= 0) ? ret : 0x1031; /* backward compatibility */ writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR); @@ -388,7 +401,7 @@ static void __devinit mpc_i2c_setup_8xxx(struct device_node *node, if (ret >= 0) dev_info(i2c->dev, "clock %d Hz (dfsrr=%d fdr=%d)\n", - clock, fdr >> 8, fdr & 0xff); + i2c->real_clk, fdr >> 8, fdr & 0xff); } #else /* !CONFIG_FSL_SOC */ @@ -500,10 +513,14 @@ static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) return -EINTR; } if (time_after(jiffies, orig_jiffies + HZ)) { + u8 status = readb(i2c->base + MPC_I2C_SR); + dev_dbg(i2c->dev, "timeout\n"); - if (readb(i2c->base + MPC_I2C_SR) == - (CSR_MCF | CSR_MBB | CSR_RXAK)) + if ((status & (CSR_MCF | CSR_MBB | CSR_RXAK)) != 0) { + writeb(status & ~CSR_MAL, + i2c->base + MPC_I2C_SR); mpc_i2c_fixup(i2c); + } return -EIO; } schedule(); @@ -595,6 +612,14 @@ static int __devinit fsl_i2c_probe(struct of_device *op, mpc_i2c_setup_8xxx(op->dev.of_node, i2c, clock, 0); } + prop = of_get_property(op->dev.of_node, "fsl,timeout", &plen); + if (prop && plen == sizeof(u32)) { + mpc_ops.timeout = *prop * HZ / 1000000; + if (mpc_ops.timeout < 5) + mpc_ops.timeout = 5; + } + dev_info(i2c->dev, "timeout %u us\n", mpc_ops.timeout * 1000000 / HZ); + dev_set_drvdata(&op->dev, i2c); i2c->adap = mpc_ops; |