diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-common.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-common.c | 658 |
1 files changed, 658 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c new file mode 100644 index 000000000..35f762872 --- /dev/null +++ b/drivers/i2c/busses/i2c-designware-common.c @@ -0,0 +1,658 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Synopsys DesignWare I2C adapter driver. + * + * Based on the TI DAVINCI I2C adapter driver. + * + * Copyright (C) 2006 Texas Instruments. + * Copyright (C) 2007 MontaVista Software Inc. + * Copyright (C) 2009 Provigent Ltd. + */ +#include <linux/acpi.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/export.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/pm_runtime.h> +#include <linux/regmap.h> +#include <linux/swab.h> +#include <linux/types.h> +#include <linux/units.h> + +#include "i2c-designware-core.h" + +static char *abort_sources[] = { + [ABRT_7B_ADDR_NOACK] = + "slave address not acknowledged (7bit mode)", + [ABRT_10ADDR1_NOACK] = + "first address byte not acknowledged (10bit mode)", + [ABRT_10ADDR2_NOACK] = + "second address byte not acknowledged (10bit mode)", + [ABRT_TXDATA_NOACK] = + "data not acknowledged", + [ABRT_GCALL_NOACK] = + "no acknowledgement for a general call", + [ABRT_GCALL_READ] = + "read after general call", + [ABRT_SBYTE_ACKDET] = + "start byte acknowledged", + [ABRT_SBYTE_NORSTRT] = + "trying to send start byte when restart is disabled", + [ABRT_10B_RD_NORSTRT] = + "trying to read when restart is disabled (10bit mode)", + [ABRT_MASTER_DIS] = + "trying to use disabled adapter", + [ARB_LOST] = + "lost arbitration", + [ABRT_SLAVE_FLUSH_TXFIFO] = + "read command so flush old data in the TX FIFO", + [ABRT_SLAVE_ARBLOST] = + "slave lost the bus while transmitting data to a remote master", + [ABRT_SLAVE_RD_INTX] = + "incorrect slave-transmitter mode configuration", +}; + +static int dw_reg_read(void *context, unsigned int reg, unsigned int *val) +{ + struct dw_i2c_dev *dev = context; + + *val = readl(dev->base + reg); + + return 0; +} + +static int dw_reg_write(void *context, unsigned int reg, unsigned int val) +{ + struct dw_i2c_dev *dev = context; + + writel(val, dev->base + reg); + + return 0; +} + +static int dw_reg_read_swab(void *context, unsigned int reg, unsigned int *val) +{ + struct dw_i2c_dev *dev = context; + + *val = swab32(readl(dev->base + reg)); + + return 0; +} + +static int dw_reg_write_swab(void *context, unsigned int reg, unsigned int val) +{ + struct dw_i2c_dev *dev = context; + + writel(swab32(val), dev->base + reg); + + return 0; +} + +static int dw_reg_read_word(void *context, unsigned int reg, unsigned int *val) +{ + struct dw_i2c_dev *dev = context; + + *val = readw(dev->base + reg) | + (readw(dev->base + reg + 2) << 16); + + return 0; +} + +static int dw_reg_write_word(void *context, unsigned int reg, unsigned int val) +{ + struct dw_i2c_dev *dev = context; + + writew(val, dev->base + reg); + writew(val >> 16, dev->base + reg + 2); + + return 0; +} + +/** + * i2c_dw_init_regmap() - Initialize registers map + * @dev: device private data + * + * Autodetects needed register access mode and creates the regmap with + * corresponding read/write callbacks. This must be called before doing any + * other register access. + */ +int i2c_dw_init_regmap(struct dw_i2c_dev *dev) +{ + struct regmap_config map_cfg = { + .reg_bits = 32, + .val_bits = 32, + .reg_stride = 4, + .disable_locking = true, + .reg_read = dw_reg_read, + .reg_write = dw_reg_write, + .max_register = DW_IC_COMP_TYPE, + }; + u32 reg; + int ret; + + /* + * Skip detecting the registers map configuration if the regmap has + * already been provided by a higher code. + */ + if (dev->map) + return 0; + + ret = i2c_dw_acquire_lock(dev); + if (ret) + return ret; + + reg = readl(dev->base + DW_IC_COMP_TYPE); + i2c_dw_release_lock(dev); + + if ((dev->flags & MODEL_MASK) == MODEL_AMD_NAVI_GPU) + map_cfg.max_register = AMD_UCSI_INTR_REG; + + if (reg == swab32(DW_IC_COMP_TYPE_VALUE)) { + map_cfg.reg_read = dw_reg_read_swab; + map_cfg.reg_write = dw_reg_write_swab; + } else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) { + map_cfg.reg_read = dw_reg_read_word; + map_cfg.reg_write = dw_reg_write_word; + } else if (reg != DW_IC_COMP_TYPE_VALUE) { + dev_err(dev->dev, + "Unknown Synopsys component type: 0x%08x\n", reg); + return -ENODEV; + } + + /* + * 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 + * can fail. + */ + dev->map = devm_regmap_init(dev->dev, NULL, dev, &map_cfg); + if (IS_ERR(dev->map)) { + dev_err(dev->dev, "Failed to init the registers map\n"); + return PTR_ERR(dev->map); + } + + return 0; +} + +static const u32 supported_speeds[] = { + I2C_MAX_HIGH_SPEED_MODE_FREQ, + I2C_MAX_FAST_MODE_PLUS_FREQ, + I2C_MAX_FAST_MODE_FREQ, + I2C_MAX_STANDARD_MODE_FREQ, +}; + +int i2c_dw_validate_speed(struct dw_i2c_dev *dev) +{ + struct i2c_timings *t = &dev->timings; + unsigned int i; + + /* + * Only standard mode at 100kHz, fast mode at 400kHz, + * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported. + */ + for (i = 0; i < ARRAY_SIZE(supported_speeds); i++) { + if (t->bus_freq_hz == supported_speeds[i]) + return 0; + } + + dev_err(dev->dev, + "%d Hz is unsupported, only 100kHz, 400kHz, 1MHz and 3.4MHz are supported\n", + t->bus_freq_hz); + + return -EINVAL; +} +EXPORT_SYMBOL_GPL(i2c_dw_validate_speed); + +#ifdef CONFIG_ACPI + +#include <linux/dmi.h> + +/* + * The HCNT/LCNT information coming from ACPI should be the most accurate + * for given platform. However, some systems get it wrong. On such systems + * we get better results by calculating those based on the input clock. + */ +static const struct dmi_system_id i2c_dw_no_acpi_params[] = { + { + .ident = "Dell Inspiron 7348", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"), + }, + }, + {} +}; + +static void i2c_dw_acpi_params(struct device *device, char method[], + u16 *hcnt, u16 *lcnt, u32 *sda_hold) +{ + struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; + acpi_handle handle = ACPI_HANDLE(device); + union acpi_object *obj; + + if (dmi_check_system(i2c_dw_no_acpi_params)) + return; + + if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf))) + return; + + obj = (union acpi_object *)buf.pointer; + if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) { + const union acpi_object *objs = obj->package.elements; + + *hcnt = (u16)objs[0].integer.value; + *lcnt = (u16)objs[1].integer.value; + *sda_hold = (u32)objs[2].integer.value; + } + + kfree(buf.pointer); +} + +int i2c_dw_acpi_configure(struct device *device) +{ + struct dw_i2c_dev *dev = dev_get_drvdata(device); + struct i2c_timings *t = &dev->timings; + u32 ss_ht = 0, fp_ht = 0, hs_ht = 0, fs_ht = 0; + + /* + * Try to get SDA hold time and *CNT values from an ACPI method for + * selected speed modes. + */ + i2c_dw_acpi_params(device, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, &ss_ht); + i2c_dw_acpi_params(device, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, &fs_ht); + i2c_dw_acpi_params(device, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, &fp_ht); + i2c_dw_acpi_params(device, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, &hs_ht); + + switch (t->bus_freq_hz) { + case I2C_MAX_STANDARD_MODE_FREQ: + dev->sda_hold_time = ss_ht; + break; + case I2C_MAX_FAST_MODE_PLUS_FREQ: + dev->sda_hold_time = fp_ht; + break; + case I2C_MAX_HIGH_SPEED_MODE_FREQ: + dev->sda_hold_time = hs_ht; + break; + case I2C_MAX_FAST_MODE_FREQ: + default: + 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) +{ + u32 acpi_speed; + int i; + + acpi_speed = i2c_acpi_find_bus_speed(device); + /* + * Some DSTDs use a non standard speed, round down to the lowest + * standard speed. + */ + for (i = 0; i < ARRAY_SIZE(supported_speeds); i++) { + if (acpi_speed >= supported_speeds[i]) + return supported_speeds[i]; + } + + return 0; +} + +#else /* CONFIG_ACPI */ + +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) +{ + u32 acpi_speed = i2c_dw_acpi_round_bus_speed(dev->dev); + struct i2c_timings *t = &dev->timings; + + /* + * Find bus speed from the "clock-frequency" device property, ACPI + * or by using fast mode if neither is set. + */ + if (acpi_speed && t->bus_freq_hz) + t->bus_freq_hz = min(t->bus_freq_hz, acpi_speed); + else if (acpi_speed || t->bus_freq_hz) + t->bus_freq_hz = max(t->bus_freq_hz, acpi_speed); + 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) +{ + /* + * 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. + */ + 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; +} + +u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset) +{ + /* + * Conditional expression: + * + * IC_[FS]S_SCL_LCNT + 1 >= IC_CLK * (tLOW + tf) + * + * DW I2C core starts counting the SCL CNTs for the LOW period + * of the SCL clock (tLOW) as soon as it pulls the SCL line. + * In order to meet the tLOW timing spec, we need to take into + * 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; +} + +int i2c_dw_set_sda_hold(struct dw_i2c_dev *dev) +{ + unsigned int reg; + int ret; + + ret = i2c_dw_acquire_lock(dev); + if (ret) + return ret; + + /* Configure SDA Hold Time if required */ + ret = regmap_read(dev->map, DW_IC_COMP_VERSION, ®); + if (ret) + goto err_release_lock; + + if (reg >= DW_IC_SDA_HOLD_MIN_VERS) { + if (!dev->sda_hold_time) { + /* Keep previous hold time setting if no one set it */ + ret = regmap_read(dev->map, DW_IC_SDA_HOLD, + &dev->sda_hold_time); + if (ret) + goto err_release_lock; + } + + /* + * Workaround for avoiding TX arbitration lost in case I2C + * slave pulls SDA down "too quickly" after falling edge of + * SCL by enabling non-zero SDA RX hold. Specification says it + * extends incoming SDA low to high transition while SCL is + * high but it appears to help also above issue. + */ + if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK)) + dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT; + + dev_dbg(dev->dev, "SDA Hold Time TX:RX = %d:%d\n", + dev->sda_hold_time & ~(u32)DW_IC_SDA_HOLD_RX_MASK, + dev->sda_hold_time >> DW_IC_SDA_HOLD_RX_SHIFT); + } else if (dev->set_sda_hold_time) { + dev->set_sda_hold_time(dev); + } else if (dev->sda_hold_time) { + dev_warn(dev->dev, + "Hardware too old to adjust SDA hold time.\n"); + dev->sda_hold_time = 0; + } + +err_release_lock: + i2c_dw_release_lock(dev); + + return ret; +} + +void __i2c_dw_disable(struct dw_i2c_dev *dev) +{ + unsigned int raw_intr_stats; + unsigned int enable; + int timeout = 100; + bool abort_needed; + unsigned int status; + int ret; + + regmap_read(dev->map, DW_IC_RAW_INTR_STAT, &raw_intr_stats); + regmap_read(dev->map, DW_IC_ENABLE, &enable); + + abort_needed = raw_intr_stats & DW_IC_INTR_MST_ON_HOLD; + if (abort_needed) { + 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, + 100); + if (ret) + dev_err(dev->dev, "timeout while trying to abort current transfer\n"); + } + + do { + __i2c_dw_disable_nowait(dev); + /* + * The enable status register may be unimplemented, but + * in that case this test reads zero and exits the loop. + */ + regmap_read(dev->map, DW_IC_ENABLE_STATUS, &status); + if ((status & 1) == 0) + return; + + /* + * Wait 10 times the signaling period of the highest I2C + * transfer supported by the driver (for 400KHz this is + * 25us) as described in the DesignWare I2C databook. + */ + usleep_range(25, 250); + } while (timeout--); + + dev_warn(dev->dev, "timeout in disabling adapter\n"); +} + +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)) + return 0; + return dev->get_clk_rate_khz(dev); +} + +int i2c_dw_prepare_clk(struct dw_i2c_dev *dev, bool prepare) +{ + int ret; + + if (prepare) { + /* Optional interface clock */ + ret = clk_prepare_enable(dev->pclk); + if (ret) + return ret; + + ret = clk_prepare_enable(dev->clk); + if (ret) + clk_disable_unprepare(dev->pclk); + + return ret; + } + + clk_disable_unprepare(dev->clk); + clk_disable_unprepare(dev->pclk); + + return 0; +} +EXPORT_SYMBOL_GPL(i2c_dw_prepare_clk); + +int i2c_dw_acquire_lock(struct dw_i2c_dev *dev) +{ + int ret; + + if (!dev->acquire_lock) + return 0; + + ret = dev->acquire_lock(); + if (!ret) + return 0; + + dev_err(dev->dev, "couldn't acquire bus ownership\n"); + + return ret; +} + +void i2c_dw_release_lock(struct dw_i2c_dev *dev) +{ + if (dev->release_lock) + dev->release_lock(); +} + +/* + * Waiting for bus not busy + */ +int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev) +{ + unsigned int status; + int ret; + + ret = regmap_read_poll_timeout(dev->map, DW_IC_STATUS, status, + !(status & DW_IC_STATUS_ACTIVITY), + 1100, 20000); + if (ret) { + dev_warn(dev->dev, "timeout waiting for bus ready\n"); + + i2c_recover_bus(&dev->adapter); + + regmap_read(dev->map, DW_IC_STATUS, &status); + if (!(status & DW_IC_STATUS_ACTIVITY)) + ret = 0; + } + + return ret; +} + +int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev) +{ + unsigned long abort_source = dev->abort_source; + int i; + + if (abort_source & DW_IC_TX_ABRT_NOACK) { + for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources)) + dev_dbg(dev->dev, + "%s: %s\n", __func__, abort_sources[i]); + return -EREMOTEIO; + } + + for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources)) + dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]); + + if (abort_source & DW_IC_TX_ARB_LOST) + return -EAGAIN; + else if (abort_source & DW_IC_TX_ABRT_GCALL_READ) + return -EINVAL; /* wrong msgs[] data */ + else + return -EIO; +} + +int i2c_dw_set_fifo_size(struct dw_i2c_dev *dev) +{ + u32 tx_fifo_depth, rx_fifo_depth; + unsigned int param; + int ret; + + /* DW_IC_COMP_PARAM_1 not implement for IP issue */ + if ((dev->flags & MODEL_MASK) == MODEL_WANGXUN_SP) { + dev->tx_fifo_depth = TXGBE_TX_FIFO_DEPTH; + dev->rx_fifo_depth = TXGBE_RX_FIFO_DEPTH; + + return 0; + } + + /* + * Try to detect the FIFO depth if not set by interface driver, + * the depth could be from 2 to 256 from HW spec. + */ + ret = i2c_dw_acquire_lock(dev); + if (ret) + return ret; + + ret = regmap_read(dev->map, DW_IC_COMP_PARAM_1, ¶m); + i2c_dw_release_lock(dev); + if (ret) + return ret; + + tx_fifo_depth = ((param >> 16) & 0xff) + 1; + rx_fifo_depth = ((param >> 8) & 0xff) + 1; + if (!dev->tx_fifo_depth) { + dev->tx_fifo_depth = tx_fifo_depth; + dev->rx_fifo_depth = rx_fifo_depth; + } else if (tx_fifo_depth >= 2) { + dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth, + tx_fifo_depth); + dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth, + rx_fifo_depth); + } + + return 0; +} + +u32 i2c_dw_func(struct i2c_adapter *adap) +{ + struct dw_i2c_dev *dev = i2c_get_adapdata(adap); + + return dev->functionality; +} + +void i2c_dw_disable(struct dw_i2c_dev *dev) +{ + unsigned int dummy; + int ret; + + ret = i2c_dw_acquire_lock(dev); + if (ret) + return; + + /* Disable controller */ + __i2c_dw_disable(dev); + + /* Disable all interrupts */ + regmap_write(dev->map, DW_IC_INTR_MASK, 0); + regmap_read(dev->map, DW_IC_CLR_INTR, &dummy); + + i2c_dw_release_lock(dev); +} + +MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter core"); +MODULE_LICENSE("GPL"); |