From c6c7c729a22bfeb8e63eafce48dbaeea20e68703 Mon Sep 17 00:00:00 2001 From: Dirk Behme Date: Fri, 28 Mar 2008 06:16:12 +0100 Subject: [PATCH 1/9] i2c: davinci: Fix smbus Oops with AIC33 usage This fixes Oops at kernel startup while "scanning" for TLV320AIC23IDx addresses. Additional fix from Sudhakar Rajashekhara: I think 'first byte set' should come after the write because an I2C transaction is being carried out before configuring the I2C mode register (which has bits to configure Master, Start condition etc), which causes undefined behavior. Signed-off-by: Sudhakar Rajashekhara Signed-off-by: Alexander Vasiliev Signed-off-by: Brad Griffis Signed-off-by: Dirk Behme Acked-by: Kevin Hilman --- drivers/i2c/busses/i2c-davinci.c | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index 4523364e6722..43913c1d50f5 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -113,6 +113,7 @@ struct davinci_i2c_dev { u8 *buf; size_t buf_len; int irq; + int stop; u8 terminate; struct i2c_adapter adapter; }; @@ -250,9 +251,6 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) u16 w; int r; - if (msg->len == 0) - return -EINVAL; - if (!pdata) pdata = &davinci_i2c_platform_data_default; /* Introduce a delay, required for some boards (e.g Davinci EVM) */ @@ -264,6 +262,7 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) dev->buf = msg->buf; dev->buf_len = msg->len; + dev->stop = stop; davinci_i2c_write_reg(dev, DAVINCI_I2C_CNT_REG, dev->buf_len); @@ -281,6 +280,10 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) flag |= DAVINCI_I2C_MDR_TRX; if (stop) flag |= DAVINCI_I2C_MDR_STP; + if (msg->len == 0) { + flag |= DAVINCI_I2C_MDR_RM; + flag &= ~DAVINCI_I2C_MDR_STP; + } /* Enable receive or transmit interrupts */ w = davinci_i2c_read_reg(dev, DAVINCI_I2C_IMR_REG); @@ -291,9 +294,21 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) 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); + /* + * First byte should be set here, not after interrupt, + * because transmit-data-ready interrupt can come before + * NACK-interrupt during sending of previous message and + * ICDXR may have wrong data + */ + if ((!(msg->flags & I2C_M_RD)) && dev->buf_len) { + davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG, *dev->buf++); + dev->buf_len--; + } + r = wait_for_completion_interruptible_timeout(&dev->cmd_complete, dev->adapter.timeout); if (r == 0) { @@ -372,7 +387,7 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) static u32 i2c_davinci_func(struct i2c_adapter *adap) { - return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK); + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; } static void terminate_read(struct davinci_i2c_dev *dev) @@ -431,6 +446,14 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id) case DAVINCI_I2C_IVR_ARDY: davinci_i2c_write_reg(dev, DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_ARDY); + if (((dev->buf_len == 0) && (dev->stop != 0)) || + (dev->cmd_err & DAVINCI_I2C_STR_NACK)) { + w = davinci_i2c_read_reg(dev, + DAVINCI_I2C_MDR_REG); + w |= DAVINCI_I2C_MDR_STP; + davinci_i2c_write_reg(dev, + DAVINCI_I2C_MDR_REG, w); + } complete(&dev->cmd_complete); break; From c062a2518d35a76e7db8519b2292191a47e3ab79 Mon Sep 17 00:00:00 2001 From: Chaithrika U S Date: Wed, 6 Jan 2010 14:54:57 +0530 Subject: [PATCH 2/9] i2c: davinci: misc. cleanups: remove MOD_REG_BIT and IO_ADDRESS usage Cleanup the DaVinci I2C driver. Remove MOD_REG_BIT macro. Also use ioremap instead of IO_ADDRESS macro. Signed-off-by: Chaithrika U S Acked-by: Kevin Hilman --- drivers/i2c/busses/i2c-davinci.c | 73 ++++++++++++++++---------------- 1 file changed, 36 insertions(+), 37 deletions(-) diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index 43913c1d50f5..4e33909dd3f0 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -38,7 +38,6 @@ #include #include - #include /* ----- global defines ----------------------------------------------- */ @@ -72,37 +71,29 @@ #define DAVINCI_I2C_IVR_NACK 0x02 #define DAVINCI_I2C_IVR_AL 0x01 -#define DAVINCI_I2C_STR_BB (1 << 12) -#define DAVINCI_I2C_STR_RSFULL (1 << 11) -#define DAVINCI_I2C_STR_SCD (1 << 5) -#define DAVINCI_I2C_STR_ARDY (1 << 2) -#define DAVINCI_I2C_STR_NACK (1 << 1) -#define DAVINCI_I2C_STR_AL (1 << 0) +#define DAVINCI_I2C_STR_BB BIT(12) +#define DAVINCI_I2C_STR_RSFULL BIT(11) +#define DAVINCI_I2C_STR_SCD BIT(5) +#define DAVINCI_I2C_STR_ARDY BIT(2) +#define DAVINCI_I2C_STR_NACK BIT(1) +#define DAVINCI_I2C_STR_AL BIT(0) -#define DAVINCI_I2C_MDR_NACK (1 << 15) -#define DAVINCI_I2C_MDR_STT (1 << 13) -#define DAVINCI_I2C_MDR_STP (1 << 11) -#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_MDR_NACK BIT(15) +#define DAVINCI_I2C_MDR_STT BIT(13) +#define DAVINCI_I2C_MDR_STP BIT(11) +#define DAVINCI_I2C_MDR_MST BIT(10) +#define DAVINCI_I2C_MDR_TRX BIT(9) +#define DAVINCI_I2C_MDR_XA BIT(8) +#define DAVINCI_I2C_MDR_RM BIT(7) +#define DAVINCI_I2C_MDR_IRS BIT(5) -#define DAVINCI_I2C_IMR_AAS (1 << 6) -#define DAVINCI_I2C_IMR_SCD (1 << 5) -#define DAVINCI_I2C_IMR_XRDY (1 << 4) -#define DAVINCI_I2C_IMR_RRDY (1 << 3) -#define DAVINCI_I2C_IMR_ARDY (1 << 2) -#define DAVINCI_I2C_IMR_NACK (1 << 1) -#define DAVINCI_I2C_IMR_AL (1 << 0) - -#define MOD_REG_BIT(val, mask, set) do { \ - if (set) { \ - val |= mask; \ - } else { \ - val &= ~mask; \ - } \ -} while (0) +#define DAVINCI_I2C_IMR_AAS BIT(6) +#define DAVINCI_I2C_IMR_SCD BIT(5) +#define DAVINCI_I2C_IMR_XRDY BIT(4) +#define DAVINCI_I2C_IMR_RRDY BIT(3) +#define DAVINCI_I2C_IMR_ARDY BIT(2) +#define DAVINCI_I2C_IMR_NACK BIT(1) +#define DAVINCI_I2C_IMR_AL BIT(0) struct davinci_i2c_dev { struct device *dev; @@ -156,7 +147,7 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev) /* put I2C into reset */ w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); - MOD_REG_BIT(w, DAVINCI_I2C_MDR_IRS, 0); + w &= ~DAVINCI_I2C_MDR_IRS; davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); /* NOTE: I2C Clock divider programming info @@ -206,7 +197,7 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev) /* Take the I2C module out of reset: */ w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); - MOD_REG_BIT(w, DAVINCI_I2C_MDR_IRS, 1); + w |= DAVINCI_I2C_MDR_IRS; davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); /* Enable interrupts */ @@ -288,9 +279,9 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) /* Enable receive or transmit interrupts */ w = davinci_i2c_read_reg(dev, DAVINCI_I2C_IMR_REG); if (msg->flags & I2C_M_RD) - MOD_REG_BIT(w, DAVINCI_I2C_IMR_RRDY, 1); + w |= DAVINCI_I2C_IMR_RRDY; else - MOD_REG_BIT(w, DAVINCI_I2C_IMR_XRDY, 1); + w |= DAVINCI_I2C_IMR_XRDY; davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, w); dev->terminate = 0; @@ -349,7 +340,7 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) return msg->len; if (stop) { w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); - MOD_REG_BIT(w, DAVINCI_I2C_MDR_STP, 1); + w |= DAVINCI_I2C_MDR_STP; davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); } return -EREMOTEIO; @@ -485,7 +476,7 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id) w = davinci_i2c_read_reg(dev, DAVINCI_I2C_IMR_REG); - MOD_REG_BIT(w, DAVINCI_I2C_IMR_XRDY, 0); + w &= ~DAVINCI_I2C_IMR_XRDY; davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, w); @@ -564,7 +555,12 @@ static int davinci_i2c_probe(struct platform_device *pdev) } clk_enable(dev->clk); - dev->base = (void __iomem *)IO_ADDRESS(mem->start); + dev->base = ioremap(mem->start, resource_size(mem)); + if (!dev->base) { + r = -EBUSY; + goto err_mem_ioremap; + } + i2c_davinci_init(dev); r = request_irq(dev->irq, i2c_davinci_isr, 0, pdev->name, dev); @@ -594,6 +590,8 @@ static int davinci_i2c_probe(struct platform_device *pdev) err_free_irq: free_irq(dev->irq, dev); err_unuse_clocks: + iounmap(dev->base); +err_mem_ioremap: clk_disable(dev->clk); clk_put(dev->clk); dev->clk = NULL; @@ -622,6 +620,7 @@ static int davinci_i2c_remove(struct platform_device *pdev) davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, 0); free_irq(IRQ_I2C, dev); + iounmap(dev->base); kfree(dev); mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); From 5ae5b1136e0c434b076ab1f9cb39deebf6187f55 Mon Sep 17 00:00:00 2001 From: Chaithrika U S Date: Wed, 6 Jan 2010 14:54:58 +0530 Subject: [PATCH 3/9] i2c: davinci: Add helper functions for power management Add i2c reset control and clock divider calculation functions which will be useful for power management features. Signed-off-by: Chaithrika U S Acked-by: Kevin Hilman --- drivers/i2c/busses/i2c-davinci.c | 56 +++++++++++++++++++++----------- 1 file changed, 37 insertions(+), 19 deletions(-) diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index 4e33909dd3f0..9afd9af4f550 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -126,12 +126,21 @@ static inline u16 davinci_i2c_read_reg(struct davinci_i2c_dev *i2c_dev, int reg) return __raw_readw(i2c_dev->base + reg); } -/* - * This functions configures I2C and brings I2C out of reset. - * This function is called during I2C init function. This function - * also gets called if I2C encounters any errors. - */ -static int i2c_davinci_init(struct davinci_i2c_dev *dev) +static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev, + int val) +{ + u16 w; + + w = davinci_i2c_read_reg(i2c_dev, DAVINCI_I2C_MDR_REG); + if (!val) /* put I2C into reset */ + w &= ~DAVINCI_I2C_MDR_IRS; + else /* take I2C out of reset */ + w |= DAVINCI_I2C_MDR_IRS; + + davinci_i2c_write_reg(i2c_dev, DAVINCI_I2C_MDR_REG, w); +} + +static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev) { struct davinci_i2c_platform_data *pdata = dev->dev->platform_data; u16 psc; @@ -140,15 +149,6 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev) u32 clkh; u32 clkl; u32 input_clock = clk_get_rate(dev->clk); - u16 w; - - if (!pdata) - pdata = &davinci_i2c_platform_data_default; - - /* put I2C into reset */ - w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); - w &= ~DAVINCI_I2C_MDR_IRS; - davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); /* NOTE: I2C Clock divider programming info * As per I2C specs the following formulas provide prescaler @@ -180,12 +180,32 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev) davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKH_REG, clkh); davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKL_REG, clkl); + dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk); +} + +/* + * This function configures I2C and brings I2C out of reset. + * This function is called during I2C init function. This function + * also gets called if I2C encounters any errors. + */ +static int i2c_davinci_init(struct davinci_i2c_dev *dev) +{ + struct davinci_i2c_platform_data *pdata = dev->dev->platform_data; + + if (!pdata) + pdata = &davinci_i2c_platform_data_default; + + /* put I2C into reset */ + davinci_i2c_reset_ctrl(dev, 0); + + /* compute clock dividers */ + i2c_davinci_calc_clk_dividers(dev); + /* Respond at reserved "SMBus Host" slave address" (and zero); * we seem to have no option to not respond... */ davinci_i2c_write_reg(dev, DAVINCI_I2C_OAR_REG, 0x08); - 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", @@ -196,9 +216,7 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev) pdata->bus_freq, pdata->bus_delay); /* Take the I2C module out of reset: */ - w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); - w |= DAVINCI_I2C_MDR_IRS; - davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); + davinci_i2c_reset_ctrl(dev, 1); /* Enable interrupts */ davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, I2C_DAVINCI_INTR_ALL); From 68f15de976f8f90d3bc0d10160aa20b0528760d4 Mon Sep 17 00:00:00 2001 From: Chaithrika U S Date: Wed, 6 Jan 2010 14:54:59 +0530 Subject: [PATCH 4/9] i2c: davinci: Add suspend/resume support Add suspend and resume callbacks to DaVinci I2C driver. This has been tested on DA850/OMAP-L138 EVM. Signed-off-by: Chaithrika U S Acked-by: Kevin Hilman --- drivers/i2c/busses/i2c-davinci.c | 36 ++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index 9afd9af4f550..7afeb28d6d76 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -646,6 +646,41 @@ static int davinci_i2c_remove(struct platform_device *pdev) return 0; } +#ifdef CONFIG_PM +static int davinci_i2c_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct davinci_i2c_dev *i2c_dev = platform_get_drvdata(pdev); + + /* put I2C into reset */ + davinci_i2c_reset_ctrl(i2c_dev, 0); + clk_disable(i2c_dev->clk); + + return 0; +} + +static int davinci_i2c_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct davinci_i2c_dev *i2c_dev = platform_get_drvdata(pdev); + + clk_enable(i2c_dev->clk); + /* take I2C out of reset */ + davinci_i2c_reset_ctrl(i2c_dev, 1); + + return 0; +} + +static const struct dev_pm_ops davinci_i2c_pm = { + .suspend = davinci_i2c_suspend, + .resume = davinci_i2c_resume, +}; + +#define davinci_i2c_pm_ops (&davinci_i2c_pm) +#else +#define davinci_i2c_pm_ops NULL +#endif + /* work with hotplug and coldplug */ MODULE_ALIAS("platform:i2c_davinci"); @@ -655,6 +690,7 @@ static struct platform_driver davinci_i2c_driver = { .driver = { .name = "i2c_davinci", .owner = THIS_MODULE, + .pm = davinci_i2c_pm_ops, }, }; From 82c0de11b734c5acec13c0f6007466da81cd16d9 Mon Sep 17 00:00:00 2001 From: Chaithrika U S Date: Wed, 6 Jan 2010 14:55:00 +0530 Subject: [PATCH 5/9] i2c: davinci: Add cpufreq support Add cpufreq support for DaVinci I2C driver. Tested on DA850/OMAP-L138 EVM. Signed-off-by: Chaithrika U S Acked-by: Kevin Hilman --- drivers/i2c/busses/i2c-davinci.c | 63 ++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index 7afeb28d6d76..352b4e7bdd9e 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -36,6 +36,7 @@ #include #include #include +#include #include #include @@ -107,6 +108,10 @@ struct davinci_i2c_dev { int stop; u8 terminate; struct i2c_adapter adapter; +#ifdef CONFIG_CPU_FREQ + struct completion xfr_complete; + struct notifier_block freq_transition; +#endif }; /* default platform data to use if not supplied in the platform_device */ @@ -391,6 +396,11 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) if (ret < 0) return ret; } + +#ifdef CONFIG_CPU_FREQ + complete(&dev->xfr_complete); +#endif + return num; } @@ -523,6 +533,48 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id) return count ? IRQ_HANDLED : IRQ_NONE; } +#ifdef CONFIG_CPU_FREQ +static int i2c_davinci_cpufreq_transition(struct notifier_block *nb, + unsigned long val, void *data) +{ + struct davinci_i2c_dev *dev; + + dev = container_of(nb, struct davinci_i2c_dev, freq_transition); + if (val == CPUFREQ_PRECHANGE) { + wait_for_completion(&dev->xfr_complete); + davinci_i2c_reset_ctrl(dev, 0); + } else if (val == CPUFREQ_POSTCHANGE) { + i2c_davinci_calc_clk_dividers(dev); + davinci_i2c_reset_ctrl(dev, 1); + } + + return 0; +} + +static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev) +{ + dev->freq_transition.notifier_call = i2c_davinci_cpufreq_transition; + + return cpufreq_register_notifier(&dev->freq_transition, + CPUFREQ_TRANSITION_NOTIFIER); +} + +static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev) +{ + cpufreq_unregister_notifier(&dev->freq_transition, + CPUFREQ_TRANSITION_NOTIFIER); +} +#else +static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev) +{ + return 0; +} + +static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev) +{ +} +#endif + static struct i2c_algorithm i2c_davinci_algo = { .master_xfer = i2c_davinci_xfer, .functionality = i2c_davinci_func, @@ -562,6 +614,9 @@ static int davinci_i2c_probe(struct platform_device *pdev) } init_completion(&dev->cmd_complete); +#ifdef CONFIG_CPU_FREQ + init_completion(&dev->xfr_complete); +#endif dev->dev = get_device(&pdev->dev); dev->irq = irq->start; platform_set_drvdata(pdev, dev); @@ -587,6 +642,12 @@ static int davinci_i2c_probe(struct platform_device *pdev) goto err_unuse_clocks; } + r = i2c_davinci_cpufreq_register(dev); + if (r) { + dev_err(&pdev->dev, "failed to register cpufreq\n"); + goto err_free_irq; + } + adap = &dev->adapter; i2c_set_adapdata(adap, dev); adap->owner = THIS_MODULE; @@ -628,6 +689,8 @@ static int davinci_i2c_remove(struct platform_device *pdev) struct davinci_i2c_dev *dev = platform_get_drvdata(pdev); struct resource *mem; + i2c_davinci_cpufreq_deregister(dev); + platform_set_drvdata(pdev, NULL); i2c_del_adapter(&dev->adapter); put_device(&pdev->dev); From 8574faf9a5ae71fdd84c6413779a9b076138eb9e Mon Sep 17 00:00:00 2001 From: Philby John Date: Mon, 11 Jan 2010 22:39:44 +0530 Subject: [PATCH 6/9] i2c: davinci: bus recovery procedure to clear the bus Come out of i2c time out condition by following the bus recovery procedure outlined in the i2c protocol v3 spec. The kernel must be robust enough to gracefully recover from i2c bus failure without having to reset the machine. This is done by first NACKing the slave, pulsing the SCL line 9 times and then sending the stop command. This patch has been tested on a DM6446 and DM355 Signed-off-by: Philby John Signed-off-by: Srinivasan, Nageswari Acked-by: Kevin Hilman --- drivers/i2c/busses/i2c-davinci.c | 57 +++++++++++++++++++++++++++++--- 1 file changed, 53 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index 352b4e7bdd9e..2222c87876b9 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include @@ -44,6 +45,7 @@ /* ----- global defines ----------------------------------------------- */ #define DAVINCI_I2C_TIMEOUT (1*HZ) +#define DAVINCI_I2C_MAX_TRIES 2 #define I2C_DAVINCI_INTR_ALL (DAVINCI_I2C_IMR_AAS | \ DAVINCI_I2C_IMR_SCD | \ DAVINCI_I2C_IMR_ARDY | \ @@ -131,6 +133,44 @@ static inline u16 davinci_i2c_read_reg(struct davinci_i2c_dev *i2c_dev, int reg) return __raw_readw(i2c_dev->base + reg); } +/* Generate a pulse on the i2c clock pin. */ +static void generic_i2c_clock_pulse(unsigned int scl_pin) +{ + u16 i; + + if (scl_pin) { + /* Send high and low on the SCL line */ + for (i = 0; i < 9; i++) { + gpio_set_value(scl_pin, 0); + udelay(20); + gpio_set_value(scl_pin, 1); + udelay(20); + } + } +} + +/* This routine does i2c bus recovery as specified in the + * i2c protocol Rev. 03 section 3.16 titled "Bus clear" + */ +static void i2c_recover_bus(struct davinci_i2c_dev *dev) +{ + u32 flag = 0; + struct davinci_i2c_platform_data *pdata = dev->dev->platform_data; + + dev_err(dev->dev, "initiating i2c bus recovery\n"); + /* Send NACK to the slave */ + flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); + flag |= DAVINCI_I2C_MDR_NACK; + /* write the data into mode register */ + davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag); + if (pdata) + generic_i2c_clock_pulse(pdata->scl_pin); + /* Send STOP */ + flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); + flag |= DAVINCI_I2C_MDR_STP; + davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag); +} + static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev, int val) { @@ -236,14 +276,22 @@ static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev, char allow_sleep) { unsigned long timeout; + static u16 to_cnt; timeout = jiffies + dev->adapter.timeout; while (davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG) & DAVINCI_I2C_STR_BB) { - if (time_after(jiffies, timeout)) { - dev_warn(dev->dev, - "timeout waiting for bus ready\n"); - return -ETIMEDOUT; + if (to_cnt <= DAVINCI_I2C_MAX_TRIES) { + if (time_after(jiffies, timeout)) { + dev_warn(dev->dev, + "timeout waiting for bus ready\n"); + to_cnt++; + return -ETIMEDOUT; + } else { + to_cnt = 0; + i2c_recover_bus(dev); + i2c_davinci_init(dev); + } } if (allow_sleep) schedule_timeout(1); @@ -327,6 +375,7 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) dev->adapter.timeout); if (r == 0) { dev_err(dev->dev, "controller timed out\n"); + i2c_recover_bus(dev); i2c_davinci_init(dev); dev->buf_len = 0; return -ETIMEDOUT; From 21e2ecfe19df8f28408b5a607fef8704f51fa7f8 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Tue, 15 Jun 2010 10:56:45 +0200 Subject: [PATCH 7/9] i2c-pxa: fix compiler warning, due to missing const This patch adds the missing const to "struct platform_device_id" to fix this warning: /home/frogger/pengutronix/linux/linux-2.6/drivers/i2c/busses/i2c-pxa.c: In function 'i2c_pxa_probe': /home/frogger/pengutronix/linux/linux-2.6/drivers/i2c/busses/i2c-pxa.c:1004: warning: initialization discards qualifiers from pointer target type Signed-off-by: Marc Kleine-Budde Cc: Eric Miao Cc: Roel Kluin Cc: Pavel Machek Signed-off-by: Ben Dooks --- drivers/i2c/busses/i2c-pxa.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c index 020ff23d762f..c94e51b2651e 100644 --- a/drivers/i2c/busses/i2c-pxa.c +++ b/drivers/i2c/busses/i2c-pxa.c @@ -1001,7 +1001,7 @@ static int i2c_pxa_probe(struct platform_device *dev) struct pxa_i2c *i2c; struct resource *res; struct i2c_pxa_platform_data *plat = dev->dev.platform_data; - struct platform_device_id *id = platform_get_device_id(dev); + const struct platform_device_id *id = platform_get_device_id(dev); int ret; int irq; From c115167aef64717fb6b81cde957853ef16dd9551 Mon Sep 17 00:00:00 2001 From: Kevin Wells Date: Thu, 5 Aug 2010 15:40:17 -0700 Subject: [PATCH 8/9] i2c: Enable NXP LPC support in Kconfig NXP LPC series processors use the IP3204 I2C block shared with the Philips PNX4008 processor. Signed-off-by: Kevin Wells Signed-off-by: Ben Dooks --- drivers/i2c/busses/Kconfig | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index bceafbfa7268..77eabae4df8a 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -496,8 +496,8 @@ config I2C_PMCMSP will be called i2c-pmcmsp. config I2C_PNX - tristate "I2C bus support for Philips PNX targets" - depends on ARCH_PNX4008 + tristate "I2C bus support for Philips PNX and NXP LPC targets" + depends on ARCH_PNX4008 || ARCH_LPC32XX help This driver supports the Philips IP3204 I2C IP block master and/or slave controller From ededad3e6f2c7ccf0c721e71f2fd7b1ea56f520f Mon Sep 17 00:00:00 2001 From: Wan ZongShun Date: Fri, 25 Jun 2010 13:43:07 +0800 Subject: [PATCH 9/9] i2c/nuc900: add i2c driver support for nuc900 This patch is to add i2c driver support for nuc900. Signed-off-by: Wan ZongShun Reviewed-by: Marek Vasut Reviewed-by: Baruch Siach Signed-off-by: Ben Dooks --- arch/arm/mach-w90x900/include/mach/i2c.h | 9 + drivers/i2c/busses/Kconfig | 7 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-nuc900.c | 709 +++++++++++++++++++++++ 4 files changed, 726 insertions(+) create mode 100644 arch/arm/mach-w90x900/include/mach/i2c.h create mode 100644 drivers/i2c/busses/i2c-nuc900.c diff --git a/arch/arm/mach-w90x900/include/mach/i2c.h b/arch/arm/mach-w90x900/include/mach/i2c.h new file mode 100644 index 000000000000..9ffb12d06e91 --- /dev/null +++ b/arch/arm/mach-w90x900/include/mach/i2c.h @@ -0,0 +1,9 @@ +#ifndef __ASM_ARCH_NUC900_I2C_H +#define __ASM_ARCH_NUC900_I2C_H + +struct nuc900_platform_i2c { + int bus_num; + unsigned long bus_freq; +}; + +#endif /* __ASM_ARCH_NUC900_I2C_H */ diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index bceafbfa7268..ee284d2f74fd 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -448,6 +448,13 @@ config I2C_NOMADIK If you say yes to this option, support will be included for the I2C interface from ST-Ericsson's Nomadik and Ux500 architectures. +config I2C_NUC900 + tristate "NUC900 I2C Driver" + depends on ARCH_W90X900 + help + Say Y here to include support for I2C controller in the + Winbond/Nuvoton NUC900 based System-on-Chip devices. + config I2C_OCORES tristate "OpenCores I2C Controller" depends on EXPERIMENTAL diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 936880bd1dc5..c3ef49230cba 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -43,6 +43,7 @@ obj-$(CONFIG_I2C_IXP2000) += i2c-ixp2000.o obj-$(CONFIG_I2C_MPC) += i2c-mpc.o obj-$(CONFIG_I2C_MV64XXX) += i2c-mv64xxx.o obj-$(CONFIG_I2C_NOMADIK) += i2c-nomadik.o +obj-$(CONFIG_I2C_NUC900) += i2c-nuc900.o obj-$(CONFIG_I2C_OCORES) += i2c-ocores.o obj-$(CONFIG_I2C_OMAP) += i2c-omap.o obj-$(CONFIG_I2C_PASEMI) += i2c-pasemi.o diff --git a/drivers/i2c/busses/i2c-nuc900.c b/drivers/i2c/busses/i2c-nuc900.c new file mode 100644 index 000000000000..92d770d7bbc2 --- /dev/null +++ b/drivers/i2c/busses/i2c-nuc900.c @@ -0,0 +1,709 @@ +/* + * linux/drivers/i2c/busses/i2c-nuc900.c + * + * Copyright (c) 2010 Nuvoton technology corporation. + * + * This driver based on S3C2410 I2C driver of Ben Dooks . + * Written by Wan ZongShun + * + * 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;version 2 of the License. + * + */ + +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +/* nuc900 i2c registers offset */ + +#define CSR 0x00 +#define DIVIDER 0x04 +#define CMDR 0x08 +#define SWR 0x0C +#define RXR 0x10 +#define TXR 0x14 + +/* nuc900 i2c CSR register bits */ + +#define IRQEN 0x003 +#define I2CBUSY 0x400 +#define I2CSTART 0x018 +#define IRQFLAG 0x004 +#define ARBIT_LOST 0x200 +#define SLAVE_ACK 0x800 + +/* nuc900 i2c CMDR register bits */ + +#define I2C_CMD_START 0x10 +#define I2C_CMD_STOP 0x08 +#define I2C_CMD_READ 0x04 +#define I2C_CMD_WRITE 0x02 +#define I2C_CMD_NACK 0x01 + +/* i2c controller state */ + +enum nuc900_i2c_state { + STATE_IDLE, + STATE_START, + STATE_READ, + STATE_WRITE, + STATE_STOP +}; + +/* i2c controller private data */ + +struct nuc900_i2c { + spinlock_t lock; + wait_queue_head_t wait; + + struct i2c_msg *msg; + unsigned int msg_num; + unsigned int msg_idx; + unsigned int msg_ptr; + unsigned int irq; + + enum nuc900_i2c_state state; + + void __iomem *regs; + struct clk *clk; + struct device *dev; + struct resource *ioarea; + struct i2c_adapter adap; +}; + +/* nuc900_i2c_master_complete + * + * complete the message and wake up the caller, using the given return code, + * or zero to mean ok. +*/ + +static inline void nuc900_i2c_master_complete(struct nuc900_i2c *i2c, int ret) +{ + dev_dbg(i2c->dev, "master_complete %d\n", ret); + + i2c->msg_ptr = 0; + i2c->msg = NULL; + i2c->msg_idx++; + i2c->msg_num = 0; + if (ret) + i2c->msg_idx = ret; + + wake_up(&i2c->wait); +} + +/* irq enable/disable functions */ + +static inline void nuc900_i2c_disable_irq(struct nuc900_i2c *i2c) +{ + unsigned long tmp; + + tmp = readl(i2c->regs + CSR); + writel(tmp & ~IRQEN, i2c->regs + CSR); +} + +static inline void nuc900_i2c_enable_irq(struct nuc900_i2c *i2c) +{ + unsigned long tmp; + + tmp = readl(i2c->regs + CSR); + writel(tmp | IRQEN, i2c->regs + CSR); +} + + +/* nuc900_i2c_message_start + * + * put the start of a message onto the bus +*/ + +static void nuc900_i2c_message_start(struct nuc900_i2c *i2c, + struct i2c_msg *msg) +{ + unsigned int addr = (msg->addr & 0x7f) << 1; + + if (msg->flags & I2C_M_RD) + addr |= 0x1; + writel(addr & 0xff, i2c->regs + TXR); + writel(I2C_CMD_START | I2C_CMD_WRITE, i2c->regs + CMDR); +} + +static inline void nuc900_i2c_stop(struct nuc900_i2c *i2c, int ret) +{ + + dev_dbg(i2c->dev, "STOP\n"); + + /* stop the transfer */ + i2c->state = STATE_STOP; + writel(I2C_CMD_STOP, i2c->regs + CMDR); + + nuc900_i2c_master_complete(i2c, ret); + nuc900_i2c_disable_irq(i2c); +} + +/* helper functions to determine the current state in the set of + * messages we are sending +*/ + +/* is_lastmsg() + * + * returns TRUE if the current message is the last in the set +*/ + +static inline int is_lastmsg(struct nuc900_i2c *i2c) +{ + return i2c->msg_idx >= (i2c->msg_num - 1); +} + +/* is_msglast + * + * returns TRUE if we this is the last byte in the current message +*/ + +static inline int is_msglast(struct nuc900_i2c *i2c) +{ + return i2c->msg_ptr == i2c->msg->len-1; +} + +/* is_msgend + * + * returns TRUE if we reached the end of the current message +*/ + +static inline int is_msgend(struct nuc900_i2c *i2c) +{ + return i2c->msg_ptr >= i2c->msg->len; +} + +/* i2c_nuc900_irq_nextbyte + * + * process an interrupt and work out what to do + */ + +static void i2c_nuc900_irq_nextbyte(struct nuc900_i2c *i2c, + unsigned long iicstat) +{ + unsigned char byte; + + switch (i2c->state) { + + case STATE_IDLE: + dev_err(i2c->dev, "%s: called in STATE_IDLE\n", __func__); + break; + + case STATE_STOP: + dev_err(i2c->dev, "%s: called in STATE_STOP\n", __func__); + nuc900_i2c_disable_irq(i2c); + break; + + case STATE_START: + /* last thing we did was send a start condition on the + * bus, or started a new i2c message + */ + + if (iicstat & SLAVE_ACK && + !(i2c->msg->flags & I2C_M_IGNORE_NAK)) { + /* ack was not received... */ + + dev_dbg(i2c->dev, "ack was not received\n"); + nuc900_i2c_stop(i2c, -ENXIO); + break; + } + + if (i2c->msg->flags & I2C_M_RD) + i2c->state = STATE_READ; + else + i2c->state = STATE_WRITE; + + /* terminate the transfer if there is nothing to do + * as this is used by the i2c probe to find devices. + */ + + if (is_lastmsg(i2c) && i2c->msg->len == 0) { + nuc900_i2c_stop(i2c, 0); + break; + } + + if (i2c->state == STATE_READ) + goto prepare_read; + + /* fall through to the write state, as we will need to + * send a byte as well + */ + + case STATE_WRITE: + /* we are writing data to the device... check for the + * end of the message, and if so, work out what to do + */ + + if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) { + if (iicstat & SLAVE_ACK) { + dev_dbg(i2c->dev, "WRITE: No Ack\n"); + + nuc900_i2c_stop(i2c, -ECONNREFUSED); + break; + } + } + +retry_write: + + if (!is_msgend(i2c)) { + byte = i2c->msg->buf[i2c->msg_ptr++]; + writeb(byte, i2c->regs + TXR); + writel(I2C_CMD_WRITE, i2c->regs + CMDR); + + } else if (!is_lastmsg(i2c)) { + /* we need to go to the next i2c message */ + + dev_dbg(i2c->dev, "WRITE: Next Message\n"); + + i2c->msg_ptr = 0; + i2c->msg_idx++; + i2c->msg++; + + /* check to see if we need to do another message */ + if (i2c->msg->flags & I2C_M_NOSTART) { + + if (i2c->msg->flags & I2C_M_RD) { + /* cannot do this, the controller + * forces us to send a new START + * when we change direction + */ + + nuc900_i2c_stop(i2c, -EINVAL); + } + + goto retry_write; + } else { + /* send the new start */ + nuc900_i2c_message_start(i2c, i2c->msg); + i2c->state = STATE_START; + } + + } else { + /* send stop */ + + nuc900_i2c_stop(i2c, 0); + } + break; + + case STATE_READ: + /* we have a byte of data in the data register, do + * something with it, and then work out wether we are + * going to do any more read/write + */ + + byte = readb(i2c->regs + RXR); + i2c->msg->buf[i2c->msg_ptr++] = byte; + +prepare_read: + if (is_msglast(i2c)) { + /* last byte of buffer */ + + if (is_lastmsg(i2c)) + writel(I2C_CMD_READ | I2C_CMD_NACK, + i2c->regs + CMDR); + + } else if (is_msgend(i2c)) { + /* ok, we've read the entire buffer, see if there + * is anything else we need to do + */ + + if (is_lastmsg(i2c)) { + /* last message, send stop and complete */ + dev_dbg(i2c->dev, "READ: Send Stop\n"); + + nuc900_i2c_stop(i2c, 0); + } else { + /* go to the next transfer */ + dev_dbg(i2c->dev, "READ: Next Transfer\n"); + + i2c->msg_ptr = 0; + i2c->msg_idx++; + i2c->msg++; + + writel(I2C_CMD_READ, i2c->regs + CMDR); + } + + } else { + writel(I2C_CMD_READ, i2c->regs + CMDR); + } + + break; + } +} + +/* nuc900_i2c_irq + * + * top level IRQ servicing routine +*/ + +static irqreturn_t nuc900_i2c_irq(int irqno, void *dev_id) +{ + struct nuc900_i2c *i2c = dev_id; + unsigned long status; + + status = readl(i2c->regs + CSR); + writel(status | IRQFLAG, i2c->regs + CSR); + + if (status & ARBIT_LOST) { + /* deal with arbitration loss */ + dev_err(i2c->dev, "deal with arbitration loss\n"); + goto out; + } + + if (i2c->state == STATE_IDLE) { + dev_dbg(i2c->dev, "IRQ: error i2c->state == IDLE\n"); + goto out; + } + + /* pretty much this leaves us with the fact that we've + * transmitted or received whatever byte we last sent + */ + + i2c_nuc900_irq_nextbyte(i2c, status); + + out: + return IRQ_HANDLED; +} + + +/* nuc900_i2c_set_master + * + * get the i2c bus for a master transaction +*/ + +static int nuc900_i2c_set_master(struct nuc900_i2c *i2c) +{ + int timeout = 400; + + while (timeout-- > 0) { + if (((readl(i2c->regs + SWR) & I2CSTART) == I2CSTART) && + ((readl(i2c->regs + CSR) & I2CBUSY) == 0)) { + return 0; + } + + msleep(1); + } + + return -ETIMEDOUT; +} + +/* nuc900_i2c_doxfer + * + * this starts an i2c transfer +*/ + +static int nuc900_i2c_doxfer(struct nuc900_i2c *i2c, + struct i2c_msg *msgs, int num) +{ + unsigned long iicstat, timeout; + int spins = 20; + int ret; + + ret = nuc900_i2c_set_master(i2c); + if (ret != 0) { + dev_err(i2c->dev, "cannot get bus (error %d)\n", ret); + ret = -EAGAIN; + goto out; + } + + spin_lock_irq(&i2c->lock); + + i2c->msg = msgs; + i2c->msg_num = num; + i2c->msg_ptr = 0; + i2c->msg_idx = 0; + i2c->state = STATE_START; + + nuc900_i2c_message_start(i2c, msgs); + spin_unlock_irq(&i2c->lock); + + timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5); + + ret = i2c->msg_idx; + + /* having these next two as dev_err() makes life very + * noisy when doing an i2cdetect + */ + + if (timeout == 0) + dev_dbg(i2c->dev, "timeout\n"); + else if (ret != num) + dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret); + + /* ensure the stop has been through the bus */ + + dev_dbg(i2c->dev, "waiting for bus idle\n"); + + /* first, try busy waiting briefly */ + do { + iicstat = readl(i2c->regs + CSR); + } while ((iicstat & I2CBUSY) && --spins); + + /* if that timed out sleep */ + if (!spins) { + msleep(1); + iicstat = readl(i2c->regs + CSR); + } + + if (iicstat & I2CBUSY) + dev_warn(i2c->dev, "timeout waiting for bus idle\n"); + + out: + return ret; +} + +/* nuc900_i2c_xfer + * + * first port of call from the i2c bus code when an message needs + * transferring across the i2c bus. +*/ + +static int nuc900_i2c_xfer(struct i2c_adapter *adap, + struct i2c_msg *msgs, int num) +{ + struct nuc900_i2c *i2c = (struct nuc900_i2c *)adap->algo_data; + int retry; + int ret; + + nuc900_i2c_enable_irq(i2c); + + for (retry = 0; retry < adap->retries; retry++) { + + ret = nuc900_i2c_doxfer(i2c, msgs, num); + + if (ret != -EAGAIN) + return ret; + + dev_dbg(i2c->dev, "Retrying transmission (%d)\n", retry); + + udelay(100); + } + + return -EREMOTEIO; +} + +/* declare our i2c functionality */ +static u32 nuc900_i2c_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING; +} + +/* i2c bus registration info */ + +static const struct i2c_algorithm nuc900_i2c_algorithm = { + .master_xfer = nuc900_i2c_xfer, + .functionality = nuc900_i2c_func, +}; + +/* nuc900_i2c_probe + * + * called by the bus driver when a suitable device is found +*/ + +static int __devinit nuc900_i2c_probe(struct platform_device *pdev) +{ + struct nuc900_i2c *i2c; + struct nuc900_platform_i2c *pdata; + struct resource *res; + int ret; + + pdata = pdev->dev.platform_data; + if (!pdata) { + dev_err(&pdev->dev, "no platform data\n"); + return -EINVAL; + } + + i2c = kzalloc(sizeof(struct nuc900_i2c), GFP_KERNEL); + if (!i2c) { + dev_err(&pdev->dev, "no memory for state\n"); + return -ENOMEM; + } + + strlcpy(i2c->adap.name, "nuc900-i2c0", sizeof(i2c->adap.name)); + i2c->adap.owner = THIS_MODULE; + i2c->adap.algo = &nuc900_i2c_algorithm; + i2c->adap.retries = 2; + i2c->adap.class = I2C_CLASS_HWMON | I2C_CLASS_SPD; + + spin_lock_init(&i2c->lock); + init_waitqueue_head(&i2c->wait); + + /* find the clock and enable it */ + + i2c->dev = &pdev->dev; + i2c->clk = clk_get(&pdev->dev, NULL); + if (IS_ERR(i2c->clk)) { + dev_err(&pdev->dev, "cannot get clock\n"); + ret = -ENOENT; + goto err_noclk; + } + + dev_dbg(&pdev->dev, "clock source %p\n", i2c->clk); + + clk_enable(i2c->clk); + + /* map the registers */ + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (res == NULL) { + dev_err(&pdev->dev, "cannot find IO resource\n"); + ret = -ENOENT; + goto err_clk; + } + + i2c->ioarea = request_mem_region(res->start, resource_size(res), + pdev->name); + + if (i2c->ioarea == NULL) { + dev_err(&pdev->dev, "cannot request IO\n"); + ret = -ENXIO; + goto err_clk; + } + + i2c->regs = ioremap(res->start, resource_size(res)); + + if (i2c->regs == NULL) { + dev_err(&pdev->dev, "cannot map IO\n"); + ret = -ENXIO; + goto err_ioarea; + } + + dev_dbg(&pdev->dev, "registers %p (%p, %p)\n", + i2c->regs, i2c->ioarea, res); + + /* setup info block for the i2c core */ + + i2c->adap.algo_data = i2c; + i2c->adap.dev.parent = &pdev->dev; + + mfp_set_groupg(&pdev->dev); + + clk_get_rate(i2c->clk); + + ret = (i2c->clk.apbfreq)/(pdata->bus_freq * 5) - 1; + writel(ret & 0xffff, i2c->regs + DIVIDER); + + /* find the IRQ for this unit (note, this relies on the init call to + * ensure no current IRQs pending + */ + + i2c->irq = ret = platform_get_irq(pdev, 0); + if (ret <= 0) { + dev_err(&pdev->dev, "cannot find IRQ\n"); + goto err_iomap; + } + + ret = request_irq(i2c->irq, nuc900_i2c_irq, IRQF_DISABLED | IRQF_SHARED, + dev_name(&pdev->dev), i2c); + + if (ret != 0) { + dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq); + goto err_iomap; + } + + /* Note, previous versions of the driver used i2c_add_adapter() + * to add the bus at any number. We now pass the bus number via + * the platform data, so if unset it will now default to always + * being bus 0. + */ + + i2c->adap.nr = pdata->bus_num; + + ret = i2c_add_numbered_adapter(&i2c->adap); + if (ret < 0) { + dev_err(&pdev->dev, "failed to add bus to i2c core\n"); + goto err_irq; + } + + platform_set_drvdata(pdev, i2c); + + dev_info(&pdev->dev, "%s: NUC900 I2C adapter\n", + dev_name(&i2c->adap.dev)); + return 0; + + err_irq: + free_irq(i2c->irq, i2c); + + err_iomap: + iounmap(i2c->regs); + + err_ioarea: + release_resource(i2c->ioarea); + kfree(i2c->ioarea); + + err_clk: + clk_disable(i2c->clk); + clk_put(i2c->clk); + + err_noclk: + kfree(i2c); + return ret; +} + +/* nuc900_i2c_remove + * + * called when device is removed from the bus +*/ + +static int __devexit nuc900_i2c_remove(struct platform_device *pdev) +{ + struct nuc900_i2c *i2c = platform_get_drvdata(pdev); + + i2c_del_adapter(&i2c->adap); + free_irq(i2c->irq, i2c); + + clk_disable(i2c->clk); + clk_put(i2c->clk); + + iounmap(i2c->regs); + + release_resource(i2c->ioarea); + kfree(i2c->ioarea); + kfree(i2c); + + return 0; +} + +static struct platform_driver nuc900_i2c_driver = { + .probe = nuc900_i2c_probe, + .remove = __devexit_p(nuc900_i2c_remove), + .driver = { + .owner = THIS_MODULE, + .name = "nuc900-i2c0", + }, +}; + +static int __init i2c_adap_nuc900_init(void) +{ + return platform_driver_register(&nuc900_i2c_driver); +} + +static void __exit i2c_adap_nuc900_exit(void) +{ + platform_driver_unregister(&nuc900_i2c_driver); +} +subsys_initcall(i2c_adap_nuc900_init); +module_exit(i2c_adap_nuc900_exit); + +MODULE_DESCRIPTION("NUC900 I2C Bus driver"); +MODULE_AUTHOR("Wan ZongShun, "); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:nuc900-i2c0");