diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-14 18:57:54 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-14 18:57:54 (GMT) |
commit | d0a0c28cf178943afaf22f87957b73c47497cb4b (patch) | |
tree | c07ee70a42bdf046d0ce8540b4e86d2c16f05b6c /drivers/i2c/busses | |
parent | ce00f7feb0a497b4280e1efe16e03728ed292687 (diff) | |
parent | f6e1901c4c596238abe6735bb20593f2734f757e (diff) | |
download | linux-d0a0c28cf178943afaf22f87957b73c47497cb4b.tar.xz |
Merge branch 'for-linus/i2c-2636' of git://git.fluff.org/bjdooks/linux
* 'for-linus/i2c-2636' of git://git.fluff.org/bjdooks/linux:
i2c/nuc900: add i2c driver support for nuc900
i2c: Enable NXP LPC support in Kconfig
i2c-pxa: fix compiler warning, due to missing const
i2c: davinci: bus recovery procedure to clear the bus
i2c: davinci: Add cpufreq support
i2c: davinci: Add suspend/resume support
i2c: davinci: Add helper functions for power management
i2c: davinci: misc. cleanups: remove MOD_REG_BIT and IO_ADDRESS usage
i2c: davinci: Fix smbus Oops with AIC33 usage
Diffstat (limited to 'drivers/i2c/busses')
-rw-r--r-- | drivers/i2c/busses/Kconfig | 11 | ||||
-rw-r--r-- | drivers/i2c/busses/Makefile | 1 | ||||
-rw-r--r-- | drivers/i2c/busses/i2c-davinci.c | 314 | ||||
-rw-r--r-- | drivers/i2c/busses/i2c-nuc900.c | 709 | ||||
-rw-r--r-- | drivers/i2c/busses/i2c-pxa.c | 2 |
5 files changed, 971 insertions, 66 deletions
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 15a9702..6539ac2 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 @@ -496,8 +503,8 @@ 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 diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 936880b..c3ef492 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-davinci.c b/drivers/i2c/busses/i2c-davinci.c index 4523364..2222c87 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -36,14 +36,16 @@ #include <linux/platform_device.h> #include <linux/io.h> #include <linux/slab.h> +#include <linux/cpufreq.h> +#include <linux/gpio.h> #include <mach/hardware.h> - #include <mach/i2c.h> /* ----- 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 | \ @@ -72,37 +74,29 @@ #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_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_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_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 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 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; @@ -113,8 +107,13 @@ struct davinci_i2c_dev { u8 *buf; size_t buf_len; int irq; + 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 */ @@ -134,12 +133,59 @@ 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. +/* 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 int i2c_davinci_init(struct davinci_i2c_dev *dev) +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) +{ + 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; @@ -148,15 +194,6 @@ 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); - MOD_REG_BIT(w, DAVINCI_I2C_MDR_IRS, 0); - 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 @@ -188,12 +225,32 @@ 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", @@ -204,9 +261,7 @@ 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); - MOD_REG_BIT(w, DAVINCI_I2C_MDR_IRS, 1); - 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); @@ -221,14 +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); @@ -250,9 +313,6 @@ 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 +324,7 @@ 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); @@ -281,23 +342,40 @@ 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); 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; + /* 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) { dev_err(dev->dev, "controller timed out\n"); + i2c_recover_bus(dev); i2c_davinci_init(dev); dev->buf_len = 0; return -ETIMEDOUT; @@ -334,7 +412,7 @@ 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; @@ -367,12 +445,17 @@ 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; } 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 +514,14 @@ 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; @@ -462,7 +553,7 @@ 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); @@ -491,6 +582,48 @@ 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, @@ -530,6 +663,9 @@ 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); @@ -541,7 +677,12 @@ 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); @@ -550,6 +691,12 @@ 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; @@ -571,6 +718,8 @@ 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; @@ -589,6 +738,8 @@ 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); @@ -599,6 +750,7 @@ 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); @@ -606,6 +758,41 @@ 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"); @@ -615,6 +802,7 @@ static struct platform_driver davinci_i2c_driver = { .driver = { .name = "i2c_davinci", .owner = THIS_MODULE, + .pm = davinci_i2c_pm_ops, }, }; diff --git a/drivers/i2c/busses/i2c-nuc900.c b/drivers/i2c/busses/i2c-nuc900.c new file mode 100644 index 0000000..92d770d --- /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 <ben-Y5A6D6n0/KfQXOPxS62xeg@public.gmane.org>. + * Written by Wan ZongShun <mcuos.com-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> + * + * 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 <linux/kernel.h> +#include <linux/module.h> + +#include <linux/i2c.h> +#include <linux/i2c-id.h> +#include <linux/init.h> +#include <linux/time.h> +#include <linux/interrupt.h> +#include <linux/delay.h> +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/platform_device.h> +#include <linux/clk.h> +#include <linux/cpufreq.h> +#include <linux/slab.h> +#include <linux/io.h> + +#include <mach/mfp.h> +#include <mach/i2c.h> + +/* 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, <mcuos.com-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:nuc900-i2c0"); diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c index 020ff23..c94e51b 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; |