diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-s3c2410.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-s3c2410.c | 263 |
1 files changed, 76 insertions, 187 deletions
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c index 2f2e28d60ef5..8138f5ef40f0 100644 --- a/drivers/i2c/busses/i2c-s3c2410.c +++ b/drivers/i2c/busses/i2c-s3c2410.c @@ -1,19 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* linux/drivers/i2c/busses/i2c-s3c2410.c * * Copyright (C) 2004,2005,2009 Simtec Electronics * Ben Dooks <ben@simtec.co.uk> * * S3C2410 I2C Controller - * - * 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; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. */ #include <linux/kernel.h> @@ -33,7 +24,7 @@ #include <linux/slab.h> #include <linux/io.h> #include <linux/of.h> -#include <linux/of_gpio.h> +#include <linux/gpio/consumer.h> #include <linux/pinctrl/consumer.h> #include <linux/mfd/syscon.h> #include <linux/regmap.h> @@ -85,6 +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 @@ -104,7 +96,6 @@ enum s3c24xx_i2c_state { struct s3c24xx_i2c { wait_queue_head_t wait; kernel_ulong_t quirks; - unsigned int suspended:1; struct i2c_msg *msg; unsigned int msg_num; @@ -123,11 +114,8 @@ struct s3c24xx_i2c { struct i2c_adapter adap; struct s3c2410_platform_i2c *pdata; - int gpios[2]; + 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; }; @@ -142,15 +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) }, @@ -166,12 +153,8 @@ MODULE_DEVICE_TABLE(of, s3c24xx_i2c_match); */ static inline kernel_ulong_t s3c24xx_get_device_quirks(struct platform_device *pdev) { - if (pdev->dev.of_node) { - const struct of_device_id *match; - - match = of_match_node(s3c24xx_i2c_match, pdev->dev.of_node); - return (kernel_ulong_t)match->data; - } + if (pdev->dev.of_node) + return (kernel_ulong_t)of_device_get_match_data(&pdev->dev); return platform_get_device_id(pdev)->driver_data; } @@ -191,7 +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); } @@ -233,8 +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; @@ -287,16 +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) @@ -394,11 +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) { @@ -445,7 +426,7 @@ static int i2c_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat) * fall through to the write state, as we will need to * send a byte as well */ - + fallthrough; case STATE_WRITE: /* * we are writing data to the device... check for the @@ -493,7 +474,10 @@ static int i2c_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat) * forces us to send a new START * when we change direction */ + dev_dbg(i2c->dev, + "missing START before write->read\n"); s3c24xx_i2c_stop(i2c, -EINVAL); + break; } goto retry_write; @@ -558,7 +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; } /* @@ -700,12 +684,9 @@ 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; - if (i2c->suspended) - return -EIO; - ret = s3c24xx_i2c_set_master(i2c); if (ret != 0) { dev_err(i2c->dev, "cannot get bus (error %d)\n", ret); @@ -722,24 +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); @@ -791,17 +775,33 @@ 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) { - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_NOSTART | + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL_ALL | I2C_FUNC_NOSTART | I2C_FUNC_PROTOCOL_MANGLING; } /* 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, }; /* @@ -847,11 +847,11 @@ static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got) int freq; i2c->clkrate = clkin; - clkin /= 1000; /* clkin now in KHz */ + clkin /= 1000; /* clkin now in KHz */ dev_dbg(i2c->dev, "pdata desired frequency %lu\n", pdata->frequency); - target_frequency = pdata->frequency ? pdata->frequency : 100000; + target_frequency = pdata->frequency ?: I2C_MAX_STANDARD_MODE_FREQ; target_frequency /= 1000; /* Target frequency now in KHz */ @@ -898,115 +898,30 @@ 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) { - int idx, gpio, ret; + int i; if (i2c->quirks & QUIRK_NO_GPIO) return 0; - for (idx = 0; idx < 2; idx++) { - gpio = of_get_gpio(i2c->dev->of_node, idx); - if (!gpio_is_valid(gpio)) { - dev_err(i2c->dev, "invalid gpio[%d]: %d\n", idx, gpio); - goto free_gpio; - } - i2c->gpios[idx] = gpio; - - ret = gpio_request(gpio, "i2c-bus"); - if (ret) { - dev_err(i2c->dev, "gpio [%d] request failed (%d)\n", - gpio, ret); - goto free_gpio; + for (i = 0; i < 2; i++) { + i2c->gpios[i] = devm_gpiod_get_index(i2c->dev, NULL, + i, GPIOD_ASIS); + if (IS_ERR(i2c->gpios[i])) { + dev_err(i2c->dev, "i2c gpio invalid at index %d\n", i); + return -EINVAL; } } return 0; - -free_gpio: - while (--idx >= 0) - gpio_free(i2c->gpios[idx]); - return -EINVAL; } -static void s3c24xx_i2c_dt_gpio_free(struct s3c24xx_i2c *i2c) -{ - unsigned int idx; - - if (i2c->quirks & QUIRK_NO_GPIO) - return; - - for (idx = 0; idx < 2; idx++) - gpio_free(i2c->gpios[idx]); -} #else static int s3c24xx_i2c_parse_dt_gpio(struct s3c24xx_i2c *i2c) { return 0; } - -static void s3c24xx_i2c_dt_gpio_free(struct s3c24xx_i2c *i2c) -{ -} #endif /* @@ -1115,7 +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; @@ -1135,9 +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); @@ -1176,8 +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; } @@ -1191,13 +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 @@ -1214,7 +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; } @@ -1223,7 +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); @@ -1231,22 +1135,14 @@ static int s3c24xx_i2c_remove(struct platform_device *pdev) pm_runtime_disable(&pdev->dev); - s3c24xx_i2c_deregister_cpufreq(i2c); - i2c_del_adapter(&i2c->adap); - - if (pdev->dev.of_node && IS_ERR(i2c->pctrl)) - s3c24xx_i2c_dt_gpio_free(i2c); - - return 0; } -#ifdef CONFIG_PM_SLEEP static int s3c24xx_i2c_suspend_noirq(struct device *dev) { struct s3c24xx_i2c *i2c = dev_get_drvdata(dev); - i2c->suspended = 1; + i2c_mark_adapter_suspended(&i2c->adap); if (!IS_ERR(i2c->sysreg)) regmap_read(i2c->sysreg, EXYNOS5_SYS_I2C_CFG, &i2c->sys_i2c_cfg); @@ -1267,30 +1163,23 @@ static int s3c24xx_i2c_resume_noirq(struct device *dev) return ret; s3c24xx_i2c_init(i2c); clk_disable(i2c->clk); - i2c->suspended = 0; + i2c_mark_adapter_resumed(&i2c->adap); 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), }, }; @@ -1308,5 +1197,5 @@ static void __exit i2c_adap_s3c_exit(void) module_exit(i2c_adap_s3c_exit); MODULE_DESCRIPTION("S3C24XX I2C Bus driver"); -MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>"); +MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); MODULE_LICENSE("GPL"); |