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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/i2c/busses/i2c-designware-common.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-common.c')
-rw-r--r--drivers/i2c/busses/i2c-designware-common.c637
1 files changed, 637 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..ad98c85ec
--- /dev/null
+++ b/drivers/i2c/busses/i2c-designware-common.c
@@ -0,0 +1,637 @@
+// 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)
+{
+ u32 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, &reg);
+ 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)
+{
+ int timeout = 100;
+ u32 status;
+
+ 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)
+{
+ u32 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 param, tx_fifo_depth, rx_fifo_depth;
+ int ret;
+
+ /*
+ * 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, &param);
+ 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)
+{
+ u32 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);
+}
+
+void i2c_dw_disable_int(struct dw_i2c_dev *dev)
+{
+ regmap_write(dev->map, DW_IC_INTR_MASK, 0);
+}
+
+MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter core");
+MODULE_LICENSE("GPL");