diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-s3c2410.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-s3c2410.c | 177 |
1 files changed, 54 insertions, 123 deletions
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c index 4d82761e1585..8138f5ef40f0 100644 --- a/drivers/i2c/busses/i2c-s3c2410.c +++ b/drivers/i2c/busses/i2c-s3c2410.c @@ -24,7 +24,6 @@ #include <linux/slab.h> #include <linux/io.h> #include <linux/of.h> -#include <linux/of_device.h> #include <linux/gpio/consumer.h> #include <linux/pinctrl/consumer.h> #include <linux/mfd/syscon.h> @@ -77,6 +76,7 @@ #define QUIRK_HDMIPHY (1 << 1) #define QUIRK_NO_GPIO (1 << 2) #define QUIRK_POLL (1 << 3) +#define QUIRK_ATOMIC (1 << 4) /* Max time to wait for bus to become idle after a xfer (in us) */ #define S3C2410_IDLE_TIMEOUT 5000 @@ -116,9 +116,6 @@ struct s3c24xx_i2c { struct s3c2410_platform_i2c *pdata; struct gpio_desc *gpios[2]; struct pinctrl *pctrl; -#if defined(CONFIG_ARM_S3C24XX_CPUFREQ) - struct notifier_block freq_transition; -#endif struct regmap *sysreg; unsigned int sys_i2c_cfg; }; @@ -133,15 +130,14 @@ static const struct platform_device_id s3c24xx_driver_ids[] = { }, { .name = "s3c2440-hdmiphy-i2c", .driver_data = QUIRK_S3C2440 | QUIRK_HDMIPHY | QUIRK_NO_GPIO, - }, { }, + }, { } }; MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids); -static int i2c_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat); +static void i2c_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat); #ifdef CONFIG_OF static const struct of_device_id s3c24xx_i2c_match[] = { - { .compatible = "samsung,s3c2410-i2c", .data = (void *)0 }, { .compatible = "samsung,s3c2440-i2c", .data = (void *)QUIRK_S3C2440 }, { .compatible = "samsung,s3c2440-hdmiphy-i2c", .data = (void *)(QUIRK_S3C2440 | QUIRK_HDMIPHY | QUIRK_NO_GPIO) }, @@ -178,7 +174,7 @@ static inline void s3c24xx_i2c_master_complete(struct s3c24xx_i2c *i2c, int ret) if (ret) i2c->msg_idx = ret; - if (!(i2c->quirks & QUIRK_POLL)) + if (!(i2c->quirks & (QUIRK_POLL | QUIRK_ATOMIC))) wake_up(&i2c->wait); } @@ -220,8 +216,17 @@ static bool is_ack(struct s3c24xx_i2c *i2c) int tries; for (tries = 50; tries; --tries) { - if (readl(i2c->regs + S3C2410_IICCON) - & S3C2410_IICCON_IRQPEND) { + unsigned long tmp = readl(i2c->regs + S3C2410_IICCON); + + if (!(tmp & S3C2410_IICCON_ACKEN)) { + /* + * Wait a bit for the bus to stabilize, + * delay estimated experimentally. + */ + usleep_range(100, 200); + return true; + } + if (tmp & S3C2410_IICCON_IRQPEND) { if (!(readl(i2c->regs + S3C2410_IICSTAT) & S3C2410_IICSTAT_LASTBIT)) return true; @@ -274,16 +279,6 @@ static void s3c24xx_i2c_message_start(struct s3c24xx_i2c *i2c, stat |= S3C2410_IICSTAT_START; writel(stat, i2c->regs + S3C2410_IICSTAT); - - if (i2c->quirks & QUIRK_POLL) { - while ((i2c->msg_num != 0) && is_ack(i2c)) { - i2c_s3c_irq_nextbyte(i2c, stat); - stat = readl(i2c->regs + S3C2410_IICSTAT); - - if (stat & S3C2410_IICSTAT_ARBITR) - dev_err(i2c->dev, "deal with arbitration loss\n"); - } - } } static inline void s3c24xx_i2c_stop(struct s3c24xx_i2c *i2c, int ret) @@ -381,11 +376,10 @@ static inline int is_msgend(struct s3c24xx_i2c *i2c) /* * process an interrupt and work out what to do */ -static int i2c_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat) +static void i2c_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat) { unsigned long tmp; unsigned char byte; - int ret = 0; switch (i2c->state) { @@ -548,7 +542,7 @@ static int i2c_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat) tmp &= ~S3C2410_IICCON_IRQPEND; writel(tmp, i2c->regs + S3C2410_IICCON); out: - return ret; + return; } /* @@ -690,7 +684,7 @@ static void s3c24xx_i2c_wait_idle(struct s3c24xx_i2c *i2c) static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c, struct i2c_msg *msgs, int num) { - unsigned long timeout; + long time_left = 0; int ret; ret = s3c24xx_i2c_set_master(i2c); @@ -709,24 +703,27 @@ static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c, s3c24xx_i2c_enable_irq(i2c); s3c24xx_i2c_message_start(i2c, msgs); - if (i2c->quirks & QUIRK_POLL) { - ret = i2c->msg_idx; + if (i2c->quirks & (QUIRK_POLL | QUIRK_ATOMIC)) { + while ((i2c->msg_num != 0) && is_ack(i2c)) { + unsigned long stat = readl(i2c->regs + S3C2410_IICSTAT); - if (ret != num) - dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret); + i2c_s3c_irq_nextbyte(i2c, stat); - goto out; + stat = readl(i2c->regs + S3C2410_IICSTAT); + if (stat & S3C2410_IICSTAT_ARBITR) + dev_err(i2c->dev, "deal with arbitration loss\n"); + } + } else { + time_left = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5); } - 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) + if (time_left == 0) dev_dbg(i2c->dev, "timeout\n"); else if (ret != num) dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret); @@ -778,6 +775,21 @@ static int s3c24xx_i2c_xfer(struct i2c_adapter *adap, return -EREMOTEIO; } +static int s3c24xx_i2c_xfer_atomic(struct i2c_adapter *adap, + struct i2c_msg *msgs, int num) +{ + struct s3c24xx_i2c *i2c = (struct s3c24xx_i2c *)adap->algo_data; + int ret; + + disable_irq(i2c->irq); + i2c->quirks |= QUIRK_ATOMIC; + ret = s3c24xx_i2c_xfer(adap, msgs, num); + i2c->quirks &= ~QUIRK_ATOMIC; + enable_irq(i2c->irq); + + return ret; +} + /* declare our i2c functionality */ static u32 s3c24xx_i2c_func(struct i2c_adapter *adap) { @@ -787,8 +799,9 @@ static u32 s3c24xx_i2c_func(struct i2c_adapter *adap) /* i2c bus registration info */ static const struct i2c_algorithm s3c24xx_i2c_algorithm = { - .master_xfer = s3c24xx_i2c_xfer, - .functionality = s3c24xx_i2c_func, + .xfer = s3c24xx_i2c_xfer, + .xfer_atomic = s3c24xx_i2c_xfer_atomic, + .functionality = s3c24xx_i2c_func, }; /* @@ -885,65 +898,6 @@ static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got) return 0; } -#if defined(CONFIG_ARM_S3C24XX_CPUFREQ) - -#define freq_to_i2c(_n) container_of(_n, struct s3c24xx_i2c, freq_transition) - -static int s3c24xx_i2c_cpufreq_transition(struct notifier_block *nb, - unsigned long val, void *data) -{ - struct s3c24xx_i2c *i2c = freq_to_i2c(nb); - unsigned int got; - int delta_f; - int ret; - - delta_f = clk_get_rate(i2c->clk) - i2c->clkrate; - - /* if we're post-change and the input clock has slowed down - * or at pre-change and the clock is about to speed up, then - * adjust our clock rate. <0 is slow, >0 speedup. - */ - - if ((val == CPUFREQ_POSTCHANGE && delta_f < 0) || - (val == CPUFREQ_PRECHANGE && delta_f > 0)) { - i2c_lock_bus(&i2c->adap, I2C_LOCK_ROOT_ADAPTER); - ret = s3c24xx_i2c_clockrate(i2c, &got); - i2c_unlock_bus(&i2c->adap, I2C_LOCK_ROOT_ADAPTER); - - if (ret < 0) - dev_err(i2c->dev, "cannot find frequency (%d)\n", ret); - else - dev_info(i2c->dev, "setting freq %d\n", got); - } - - return 0; -} - -static inline int s3c24xx_i2c_register_cpufreq(struct s3c24xx_i2c *i2c) -{ - i2c->freq_transition.notifier_call = s3c24xx_i2c_cpufreq_transition; - - return cpufreq_register_notifier(&i2c->freq_transition, - CPUFREQ_TRANSITION_NOTIFIER); -} - -static inline void s3c24xx_i2c_deregister_cpufreq(struct s3c24xx_i2c *i2c) -{ - cpufreq_unregister_notifier(&i2c->freq_transition, - CPUFREQ_TRANSITION_NOTIFIER); -} - -#else -static inline int s3c24xx_i2c_register_cpufreq(struct s3c24xx_i2c *i2c) -{ - return 0; -} - -static inline void s3c24xx_i2c_deregister_cpufreq(struct s3c24xx_i2c *i2c) -{ -} -#endif - #ifdef CONFIG_OF static int s3c24xx_i2c_parse_dt_gpio(struct s3c24xx_i2c *i2c) { @@ -1076,7 +1030,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev) else s3c24xx_i2c_parse_dt(pdev->dev.of_node, i2c); - strlcpy(i2c->adap.name, "s3c2410-i2c", sizeof(i2c->adap.name)); + strscpy(i2c->adap.name, "s3c2410-i2c", sizeof(i2c->adap.name)); i2c->adap.owner = THIS_MODULE; i2c->adap.algo = &s3c24xx_i2c_algorithm; i2c->adap.retries = 2; @@ -1096,9 +1050,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev) dev_dbg(&pdev->dev, "clock source %p\n", i2c->clk); /* map the registers */ - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - i2c->regs = devm_ioremap_resource(&pdev->dev, res); - + i2c->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res); if (IS_ERR(i2c->regs)) return PTR_ERR(i2c->regs); @@ -1137,8 +1089,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev) */ if (!(i2c->quirks & QUIRK_POLL)) { i2c->irq = ret = platform_get_irq(pdev, 0); - if (ret <= 0) { - dev_err(&pdev->dev, "cannot find IRQ\n"); + if (ret < 0) { clk_unprepare(i2c->clk); return ret; } @@ -1152,13 +1103,6 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev) } } - ret = s3c24xx_i2c_register_cpufreq(i2c); - if (ret < 0) { - dev_err(&pdev->dev, "failed to register cpufreq notifier\n"); - clk_unprepare(i2c->clk); - return ret; - } - /* * Note, previous versions of the driver used i2c_add_adapter() * to add the bus at any number. We now pass the bus number via @@ -1175,7 +1119,6 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev) ret = i2c_add_numbered_adapter(&i2c->adap); if (ret < 0) { pm_runtime_disable(&pdev->dev); - s3c24xx_i2c_deregister_cpufreq(i2c); clk_unprepare(i2c->clk); return ret; } @@ -1184,7 +1127,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev) return 0; } -static int s3c24xx_i2c_remove(struct platform_device *pdev) +static void s3c24xx_i2c_remove(struct platform_device *pdev) { struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev); @@ -1192,14 +1135,9 @@ static int s3c24xx_i2c_remove(struct platform_device *pdev) pm_runtime_disable(&pdev->dev); - s3c24xx_i2c_deregister_cpufreq(i2c); - i2c_del_adapter(&i2c->adap); - - return 0; } -#ifdef CONFIG_PM_SLEEP static int s3c24xx_i2c_suspend_noirq(struct device *dev) { struct s3c24xx_i2c *i2c = dev_get_drvdata(dev); @@ -1229,26 +1167,19 @@ static int s3c24xx_i2c_resume_noirq(struct device *dev) return 0; } -#endif -#ifdef CONFIG_PM static const struct dev_pm_ops s3c24xx_i2c_dev_pm_ops = { - SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(s3c24xx_i2c_suspend_noirq, - s3c24xx_i2c_resume_noirq) + NOIRQ_SYSTEM_SLEEP_PM_OPS(s3c24xx_i2c_suspend_noirq, + s3c24xx_i2c_resume_noirq) }; -#define S3C24XX_DEV_PM_OPS (&s3c24xx_i2c_dev_pm_ops) -#else -#define S3C24XX_DEV_PM_OPS NULL -#endif - static struct platform_driver s3c24xx_i2c_driver = { .probe = s3c24xx_i2c_probe, .remove = s3c24xx_i2c_remove, .id_table = s3c24xx_driver_ids, .driver = { .name = "s3c-i2c", - .pm = S3C24XX_DEV_PM_OPS, + .pm = pm_sleep_ptr(&s3c24xx_i2c_dev_pm_ops), .of_match_table = of_match_ptr(s3c24xx_i2c_match), }, }; |