diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-15 11:16:05 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-15 11:16:05 -0700 |
commit | dc221eae08eea3b0db127d1f152fac24d10b6a52 (patch) | |
tree | eea4cc64f2568db6aea94b9491120525ebcd738f /drivers/i2c/busses/i2c-davinci.c | |
parent | 98339cbd360b77c3167db287fd611468c2c44559 (diff) | |
parent | 4735c98f8447acb1c8977e2b8024640f7bf36dd6 (diff) |
Merge branch 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6
* 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6: (56 commits)
i2c: Add detection capability to new-style drivers
i2c: Call client_unregister for new-style devices too
i2c: Clean up old chip drivers
i2c-ibm_iic: Register child nodes
i2c: New-style EEPROM driver using device IDs
i2c: Export the i2c_bus_type symbol
i2c-au1550: Fix PM support
i2c-dev: Delete empty detach_client callback
i2c: Drop stray references to lm_sensors
i2c: Check for ACPI resource conflicts
i2c-ocores: basic PM support
i2c-sibyte: SWARM I2C board initialization
i2c-i801: Fix handling of error conditions
i2c-i801: Rename local variable temp to status
i2c-i801: Properly report bus arbitration loss
i2c-i801: Remove verbose debugging messages
i2c-algo-pcf: Drop unused struct members
i2c-algo-pcf: Multi-master lost-arbitration improvement
i2c: Deprecate the legacy gpio drivers
i2c-pxa: Initialize early
...
Diffstat (limited to 'drivers/i2c/busses/i2c-davinci.c')
-rw-r--r-- | drivers/i2c/busses/i2c-davinci.c | 89 |
1 files changed, 67 insertions, 22 deletions
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index 7ecbfc429b1..af3846eda98 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -85,6 +85,7 @@ #define DAVINCI_I2C_MDR_MST (1 << 10) #define DAVINCI_I2C_MDR_TRX (1 << 9) #define DAVINCI_I2C_MDR_XA (1 << 8) +#define DAVINCI_I2C_MDR_RM (1 << 7) #define DAVINCI_I2C_MDR_IRS (1 << 5) #define DAVINCI_I2C_IMR_AAS (1 << 6) @@ -112,6 +113,7 @@ struct davinci_i2c_dev { u8 *buf; size_t buf_len; int irq; + u8 terminate; struct i2c_adapter adapter; }; @@ -142,6 +144,7 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev) struct davinci_i2c_platform_data *pdata = dev->dev->platform_data; u16 psc; u32 clk; + u32 d; u32 clkh; u32 clkl; u32 input_clock = clk_get_rate(dev->clk); @@ -171,23 +174,29 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev) * if PSC > 1 , d = 5 */ - psc = 26; /* To get 1MHz clock */ + /* get minimum of 7 MHz clock, but max of 12 MHz */ + psc = (input_clock / 7000000) - 1; + if ((input_clock / (psc + 1)) > 12000000) + psc++; /* better to run under spec than over */ + d = (psc >= 2) ? 5 : 7 - psc; - clk = ((input_clock / (psc + 1)) / (pdata->bus_freq * 1000)) - 10; - clkh = (50 * clk) / 100; + clk = ((input_clock / (psc + 1)) / (pdata->bus_freq * 1000)) - (d << 1); + clkh = clk >> 1; clkl = clk - clkh; davinci_i2c_write_reg(dev, DAVINCI_I2C_PSC_REG, psc); davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKH_REG, clkh); davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKL_REG, clkl); - dev_dbg(dev->dev, "CLK = %d\n", clk); + dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk); dev_dbg(dev->dev, "PSC = %d\n", davinci_i2c_read_reg(dev, DAVINCI_I2C_PSC_REG)); dev_dbg(dev->dev, "CLKL = %d\n", davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKL_REG)); dev_dbg(dev->dev, "CLKH = %d\n", davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKH_REG)); + dev_dbg(dev->dev, "bus_freq = %dkHz, bus_delay = %d\n", + pdata->bus_freq, pdata->bus_delay); /* Take the I2C module out of reset: */ w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); @@ -233,7 +242,6 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); struct davinci_i2c_platform_data *pdata = dev->dev->platform_data; u32 flag; - u32 stat; u16 w; int r; @@ -254,12 +262,9 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) davinci_i2c_write_reg(dev, DAVINCI_I2C_CNT_REG, dev->buf_len); - init_completion(&dev->cmd_complete); + INIT_COMPLETION(dev->cmd_complete); dev->cmd_err = 0; - /* Clear any pending interrupts by reading the IVR */ - stat = davinci_i2c_read_reg(dev, DAVINCI_I2C_IVR_REG); - /* Take I2C out of reset, configure it as master and set the * start bit */ flag = DAVINCI_I2C_MDR_IRS | DAVINCI_I2C_MDR_MST | DAVINCI_I2C_MDR_STT; @@ -280,20 +285,34 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) MOD_REG_BIT(w, DAVINCI_I2C_IMR_XRDY, 1); davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, w); + dev->terminate = 0; /* write the data into mode register */ davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag); r = wait_for_completion_interruptible_timeout(&dev->cmd_complete, DAVINCI_I2C_TIMEOUT); - dev->buf_len = 0; - if (r < 0) - return r; - if (r == 0) { dev_err(dev->dev, "controller timed out\n"); i2c_davinci_init(dev); + dev->buf_len = 0; return -ETIMEDOUT; } + if (dev->buf_len) { + /* This should be 0 if all bytes were transferred + * or dev->cmd_err denotes an error. + * A signal may have aborted the transfer. + */ + if (r >= 0) { + dev_err(dev->dev, "abnormal termination buf_len=%i\n", + dev->buf_len); + r = -EREMOTEIO; + } + dev->terminate = 1; + wmb(); + dev->buf_len = 0; + } + if (r < 0) + return r; /* no error */ if (likely(!dev->cmd_err)) @@ -338,12 +357,11 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) for (i = 0; i < num; i++) { ret = i2c_davinci_xfer_msg(adap, &msgs[i], (i == (num - 1))); + dev_dbg(dev->dev, "%s [%d/%d] ret: %d\n", __func__, i + 1, num, + ret); if (ret < 0) return ret; } - - dev_dbg(dev->dev, "%s:%d ret: %d\n", __func__, __LINE__, ret); - return num; } @@ -352,6 +370,27 @@ static u32 i2c_davinci_func(struct i2c_adapter *adap) return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK); } +static void terminate_read(struct davinci_i2c_dev *dev) +{ + u16 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); + w |= DAVINCI_I2C_MDR_NACK; + davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); + + /* Throw away data */ + davinci_i2c_read_reg(dev, DAVINCI_I2C_DRR_REG); + if (!dev->terminate) + dev_err(dev->dev, "RDR IRQ while no data requested\n"); +} +static void terminate_write(struct davinci_i2c_dev *dev) +{ + u16 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); + w |= DAVINCI_I2C_MDR_RM | DAVINCI_I2C_MDR_STP; + davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); + + if (!dev->terminate) + dev_err(dev->dev, "TDR IRQ while no data to send\n"); +} + /* * Interrupt service routine. This gets called whenever an I2C interrupt * occurs. @@ -372,12 +411,15 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id) switch (stat) { case DAVINCI_I2C_IVR_AL: + /* Arbitration lost, must retry */ dev->cmd_err |= DAVINCI_I2C_STR_AL; + dev->buf_len = 0; complete(&dev->cmd_complete); break; case DAVINCI_I2C_IVR_NACK: dev->cmd_err |= DAVINCI_I2C_STR_NACK; + dev->buf_len = 0; complete(&dev->cmd_complete); break; @@ -399,9 +441,10 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id) davinci_i2c_write_reg(dev, DAVINCI_I2C_STR_REG, DAVINCI_I2C_IMR_RRDY); - } else - dev_err(dev->dev, "RDR IRQ while no " - "data requested\n"); + } else { + /* signal can terminate transfer */ + terminate_read(dev); + } break; case DAVINCI_I2C_IVR_XRDY: @@ -418,9 +461,10 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id) davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, w); - } else - dev_err(dev->dev, "TDR IRQ while no data to " - "send\n"); + } else { + /* signal can terminate transfer */ + terminate_write(dev); + } break; case DAVINCI_I2C_IVR_SCD: @@ -475,6 +519,7 @@ static int davinci_i2c_probe(struct platform_device *pdev) goto err_release_region; } + init_completion(&dev->cmd_complete); dev->dev = get_device(&pdev->dev); dev->irq = irq->start; platform_set_drvdata(pdev, dev); |