diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-common.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-common.c | 276 |
1 files changed, 220 insertions, 56 deletions
diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c index e8a688d04aee..5b1e8f74c4ac 100644 --- a/drivers/i2c/busses/i2c-designware-common.c +++ b/drivers/i2c/busses/i2c-designware-common.c @@ -8,6 +8,9 @@ * Copyright (C) 2007 MontaVista Software Inc. * Copyright (C) 2009 Provigent Ltd. */ + +#define DEFAULT_SYMBOL_NAMESPACE "I2C_DW_COMMON" + #include <linux/acpi.h> #include <linux/clk.h> #include <linux/delay.h> @@ -20,7 +23,10 @@ #include <linux/io.h> #include <linux/kernel.h> #include <linux/module.h> +#include <linux/of.h> +#include <linux/pm.h> #include <linux/pm_runtime.h> +#include <linux/property.h> #include <linux/regmap.h> #include <linux/swab.h> #include <linux/types.h> @@ -28,7 +34,7 @@ #include "i2c-designware-core.h" -static char *abort_sources[] = { +static const char *const abort_sources[] = { [ABRT_7B_ADDR_NOACK] = "slave address not acknowledged (7bit mode)", [ABRT_10ADDR1_NOACK] = @@ -122,6 +128,8 @@ static int dw_reg_write_word(void *context, unsigned int reg, unsigned int val) * Autodetects needed register access mode and creates the regmap with * corresponding read/write callbacks. This must be called before doing any * other register access. + * + * Return: 0 on success, or negative errno otherwise. */ int i2c_dw_init_regmap(struct dw_i2c_dev *dev) { @@ -169,7 +177,7 @@ int i2c_dw_init_regmap(struct dw_i2c_dev *dev) /* * Note we'll check the return value of the regmap IO accessors only * at the probe stage. The rest of the code won't do this because - * basically we have MMIO-based regmap so non of the read/write methods + * basically we have MMIO-based regmap, so none of the read/write methods * can fail. */ dev->map = devm_regmap_init(dev->dev, NULL, dev, &map_cfg); @@ -188,7 +196,7 @@ static const u32 supported_speeds[] = { I2C_MAX_STANDARD_MODE_FREQ, }; -int i2c_dw_validate_speed(struct dw_i2c_dev *dev) +static int i2c_dw_validate_speed(struct dw_i2c_dev *dev) { struct i2c_timings *t = &dev->timings; unsigned int i; @@ -208,7 +216,44 @@ int i2c_dw_validate_speed(struct dw_i2c_dev *dev) return -EINVAL; } -EXPORT_SYMBOL_GPL(i2c_dw_validate_speed); + +#ifdef CONFIG_OF + +#include <linux/platform_device.h> + +#define MSCC_ICPU_CFG_TWI_DELAY 0x0 +#define MSCC_ICPU_CFG_TWI_DELAY_ENABLE BIT(0) +#define MSCC_ICPU_CFG_TWI_SPIKE_FILTER 0x4 + +static int mscc_twi_set_sda_hold_time(struct dw_i2c_dev *dev) +{ + writel((dev->sda_hold_time << 1) | MSCC_ICPU_CFG_TWI_DELAY_ENABLE, + dev->ext + MSCC_ICPU_CFG_TWI_DELAY); + + return 0; +} + +static void i2c_dw_of_configure(struct device *device) +{ + struct platform_device *pdev = to_platform_device(device); + struct dw_i2c_dev *dev = dev_get_drvdata(device); + + switch (dev->flags & MODEL_MASK) { + case MODEL_MSCC_OCELOT: + dev->ext = devm_platform_ioremap_resource(pdev, 1); + if (!IS_ERR(dev->ext)) + dev->set_sda_hold_time = mscc_twi_set_sda_hold_time; + break; + default: + break; + } +} + +#else /* CONFIG_OF */ + +static inline void i2c_dw_of_configure(struct device *device) { } + +#endif /* CONFIG_OF */ #ifdef CONFIG_ACPI @@ -255,7 +300,7 @@ static void i2c_dw_acpi_params(struct device *device, char method[], kfree(buf.pointer); } -int i2c_dw_acpi_configure(struct device *device) +static void i2c_dw_acpi_configure(struct device *device) { struct dw_i2c_dev *dev = dev_get_drvdata(device); struct i2c_timings *t = &dev->timings; @@ -285,10 +330,7 @@ int i2c_dw_acpi_configure(struct device *device) dev->sda_hold_time = fs_ht; break; } - - return 0; } -EXPORT_SYMBOL_GPL(i2c_dw_acpi_configure); static u32 i2c_dw_acpi_round_bus_speed(struct device *device) { @@ -297,7 +339,7 @@ static u32 i2c_dw_acpi_round_bus_speed(struct device *device) acpi_speed = i2c_acpi_find_bus_speed(device); /* - * Some DSTDs use a non standard speed, round down to the lowest + * Some DSDTs use a non standard speed, round down to the lowest * standard speed. */ for (i = 0; i < ARRAY_SIZE(supported_speeds); i++) { @@ -310,11 +352,13 @@ static u32 i2c_dw_acpi_round_bus_speed(struct device *device) #else /* CONFIG_ACPI */ +static inline void i2c_dw_acpi_configure(struct device *device) { } + static inline u32 i2c_dw_acpi_round_bus_speed(struct device *device) { return 0; } #endif /* CONFIG_ACPI */ -void i2c_dw_adjust_bus_speed(struct dw_i2c_dev *dev) +static void i2c_dw_adjust_bus_speed(struct dw_i2c_dev *dev) { u32 acpi_speed = i2c_dw_acpi_round_bus_speed(dev->dev); struct i2c_timings *t = &dev->timings; @@ -330,50 +374,75 @@ void i2c_dw_adjust_bus_speed(struct dw_i2c_dev *dev) else t->bus_freq_hz = I2C_MAX_FAST_MODE_FREQ; } -EXPORT_SYMBOL_GPL(i2c_dw_adjust_bus_speed); -u32 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset) +int i2c_dw_fw_parse_and_configure(struct dw_i2c_dev *dev) +{ + struct i2c_timings *t = &dev->timings; + struct device *device = dev->dev; + struct fwnode_handle *fwnode = dev_fwnode(device); + + i2c_parse_fw_timings(device, t, false); + + if (device_property_read_u32(device, "snps,bus-capacitance-pf", &dev->bus_capacitance_pF)) + dev->bus_capacitance_pF = 100; + + dev->clk_freq_optimized = device_property_read_bool(device, "snps,clk-freq-optimized"); + + i2c_dw_adjust_bus_speed(dev); + + if (is_of_node(fwnode)) + i2c_dw_of_configure(device); + else if (is_acpi_node(fwnode)) + i2c_dw_acpi_configure(device); + + return i2c_dw_validate_speed(dev); +} +EXPORT_SYMBOL_GPL(i2c_dw_fw_parse_and_configure); + +static u32 i2c_dw_read_scl_reg(struct dw_i2c_dev *dev, u32 reg) { + u32 val; + int ret; + + ret = i2c_dw_acquire_lock(dev); + if (ret) + return 0; + + ret = regmap_read(dev->map, reg, &val); + i2c_dw_release_lock(dev); + + return ret ? 0 : val; +} + +u32 i2c_dw_scl_hcnt(struct dw_i2c_dev *dev, unsigned int reg, u32 ic_clk, + u32 tSYMBOL, u32 tf, int offset) +{ + if (!ic_clk) + return i2c_dw_read_scl_reg(dev, reg); + /* - * DesignWare I2C core doesn't seem to have solid strategy to meet - * the tHD;STA timing spec. Configuring _HCNT based on tHIGH spec - * will result in violation of the tHD;STA spec. + * Conditional expression: + * + * IC_[FS]S_SCL_HCNT + 3 >= IC_CLK * (tHD;STA + tf) + * + * This is just experimental rule; the tHD;STA period turned + * out to be proportinal to (_HCNT + 3). With this setting, + * we could meet both tHIGH and tHD;STA timing specs. + * + * If unsure, you'd better to take this alternative. + * + * The reason why we need to take into account "tf" here, + * is the same as described in i2c_dw_scl_lcnt(). */ - if (cond) - /* - * Conditional expression: - * - * IC_[FS]S_SCL_HCNT + (1+4+3) >= IC_CLK * tHIGH - * - * This is based on the DW manuals, and represents an ideal - * configuration. The resulting I2C bus speed will be - * faster than any of the others. - * - * If your hardware is free from tHD;STA issue, try this one. - */ - return DIV_ROUND_CLOSEST_ULL((u64)ic_clk * tSYMBOL, MICRO) - - 8 + offset; - else - /* - * Conditional expression: - * - * IC_[FS]S_SCL_HCNT + 3 >= IC_CLK * (tHD;STA + tf) - * - * This is just experimental rule; the tHD;STA period turned - * out to be proportinal to (_HCNT + 3). With this setting, - * we could meet both tHIGH and tHD;STA timing specs. - * - * If unsure, you'd better to take this alternative. - * - * The reason why we need to take into account "tf" here, - * is the same as described in i2c_dw_scl_lcnt(). - */ - return DIV_ROUND_CLOSEST_ULL((u64)ic_clk * (tSYMBOL + tf), MICRO) - - 3 + offset; + return DIV_ROUND_CLOSEST_ULL((u64)ic_clk * (tSYMBOL + tf), MICRO) - 3 + offset; } -u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset) +u32 i2c_dw_scl_lcnt(struct dw_i2c_dev *dev, unsigned int reg, u32 ic_clk, + u32 tLOW, u32 tf, int offset) { + if (!ic_clk) + return i2c_dw_read_scl_reg(dev, reg); + /* * Conditional expression: * @@ -385,8 +454,7 @@ u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset) * account the fall time of SCL signal (tf). Default tf value * should be 0.3 us, for safety. */ - return DIV_ROUND_CLOSEST_ULL((u64)ic_clk * (tLOW + tf), MICRO) - - 1 + offset; + return DIV_ROUND_CLOSEST_ULL((u64)ic_clk * (tLOW + tf), MICRO) - 1 + offset; } int i2c_dw_set_sda_hold(struct dw_i2c_dev *dev) @@ -441,7 +509,8 @@ err_release_lock: void __i2c_dw_disable(struct dw_i2c_dev *dev) { - unsigned int raw_intr_stats; + struct i2c_timings *t = &dev->timings; + unsigned int raw_intr_stats, ic_stats; unsigned int enable; int timeout = 100; bool abort_needed; @@ -449,10 +518,25 @@ void __i2c_dw_disable(struct dw_i2c_dev *dev) int ret; regmap_read(dev->map, DW_IC_RAW_INTR_STAT, &raw_intr_stats); + regmap_read(dev->map, DW_IC_STATUS, &ic_stats); regmap_read(dev->map, DW_IC_ENABLE, &enable); - abort_needed = raw_intr_stats & DW_IC_INTR_MST_ON_HOLD; + abort_needed = (raw_intr_stats & DW_IC_INTR_MST_ON_HOLD) || + (ic_stats & DW_IC_STATUS_MASTER_HOLD_TX_FIFO_EMPTY); if (abort_needed) { + if (!(enable & DW_IC_ENABLE_ENABLE)) { + regmap_write(dev->map, DW_IC_ENABLE, DW_IC_ENABLE_ENABLE); + /* + * Wait 10 times the signaling period of the highest I2C + * transfer supported by the driver (for 400KHz this is + * 25us) to ensure the I2C ENABLE bit is already set + * as described in the DesignWare I2C databook. + */ + fsleep(DIV_ROUND_CLOSEST_ULL(10 * MICRO, t->bus_freq_hz)); + /* Set ENABLE bit before setting ABORT */ + enable |= DW_IC_ENABLE_ENABLE; + } + regmap_write(dev->map, DW_IC_ENABLE, enable | DW_IC_ENABLE_ABORT); ret = regmap_read_poll_timeout(dev->map, DW_IC_ENABLE, enable, !(enable & DW_IC_ENABLE_ABORT), 10, @@ -473,7 +557,7 @@ void __i2c_dw_disable(struct dw_i2c_dev *dev) /* * Wait 10 times the signaling period of the highest I2C - * transfer supported by the driver (for 400KHz this is + * transfer supported by the driver (for 400kHz this is * 25us) as described in the DesignWare I2C databook. */ usleep_range(25, 250); @@ -488,8 +572,10 @@ u32 i2c_dw_clk_rate(struct dw_i2c_dev *dev) * Clock is not necessary if we got LCNT/HCNT values directly from * the platform code. */ - if (WARN_ON_ONCE(!dev->get_clk_rate_khz)) + if (!dev->get_clk_rate_khz) { + dev_dbg_once(dev->dev, "Callback get_clk_rate_khz() is not defined\n"); return 0; + } return dev->get_clk_rate_khz(dev); } @@ -580,10 +666,10 @@ int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev) if (abort_source & DW_IC_TX_ARB_LOST) return -EAGAIN; - else if (abort_source & DW_IC_TX_ABRT_GCALL_READ) + if (abort_source & DW_IC_TX_ABRT_GCALL_READ) return -EINVAL; /* wrong msgs[] data */ - else - return -EIO; + + return -EIO; } int i2c_dw_set_fifo_size(struct dw_i2c_dev *dev) @@ -653,6 +739,84 @@ void i2c_dw_disable(struct dw_i2c_dev *dev) i2c_dw_release_lock(dev); } +EXPORT_SYMBOL_GPL(i2c_dw_disable); + +int i2c_dw_probe(struct dw_i2c_dev *dev) +{ + device_set_node(&dev->adapter.dev, dev_fwnode(dev->dev)); + + switch (dev->mode) { + case DW_IC_SLAVE: + return i2c_dw_probe_slave(dev); + case DW_IC_MASTER: + return i2c_dw_probe_master(dev); + default: + dev_err(dev->dev, "Wrong operation mode: %d\n", dev->mode); + return -EINVAL; + } +} +EXPORT_SYMBOL_GPL(i2c_dw_probe); + +static int i2c_dw_prepare(struct device *device) +{ + /* + * If the ACPI companion device object is present for this device, + * it may be accessed during suspend and resume of other devices via + * I2C operation regions, so tell the PM core and middle layers to + * avoid skipping system suspend/resume callbacks for it in that case. + */ + return !has_acpi_companion(device); +} + +static int i2c_dw_runtime_suspend(struct device *device) +{ + struct dw_i2c_dev *dev = dev_get_drvdata(device); + + if (dev->shared_with_punit) + return 0; + + i2c_dw_disable(dev); + i2c_dw_prepare_clk(dev, false); + + return 0; +} + +static int i2c_dw_suspend(struct device *device) +{ + struct dw_i2c_dev *dev = dev_get_drvdata(device); + + i2c_mark_adapter_suspended(&dev->adapter); + + return i2c_dw_runtime_suspend(device); +} + +static int i2c_dw_runtime_resume(struct device *device) +{ + struct dw_i2c_dev *dev = dev_get_drvdata(device); + + if (!dev->shared_with_punit) + i2c_dw_prepare_clk(dev, true); + + dev->init(dev); + + return 0; +} + +static int i2c_dw_resume(struct device *device) +{ + struct dw_i2c_dev *dev = dev_get_drvdata(device); + + i2c_dw_runtime_resume(device); + i2c_mark_adapter_resumed(&dev->adapter); + + return 0; +} + +EXPORT_GPL_DEV_PM_OPS(i2c_dw_dev_pm_ops) = { + .prepare = pm_sleep_ptr(i2c_dw_prepare), + LATE_SYSTEM_SLEEP_PM_OPS(i2c_dw_suspend, i2c_dw_resume) + RUNTIME_PM_OPS(i2c_dw_runtime_suspend, i2c_dw_runtime_resume, NULL) +}; MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter core"); MODULE_LICENSE("GPL"); |