[PATCH v3 06/12] i2c: Add support for ADI SC5XX-family I2C peripheral
Greg Malysa
malysagreg at gmail.com
Wed Feb 26 18:30:28 CET 2025
From: Nathan Barrett-Morrison <nathan.morrison at timesys.com>
Co-developed-by: Greg Malysa <malysagreg at gmail.com>
Signed-off-by: Greg Malysa <malysagreg at gmail.com>
Co-developed-by: Ian Roberts <ian.roberts at timesys.com>
Signed-off-by: Ian Roberts <ian.roberts at timesys.com>
Co-developed-by: Angelo Dureghello <angelo.dureghello at timesys.com>
Signed-off-by: Angelo Dureghello <angelo.dureghello at timesys.com>
Signed-off-by: Vasileios Bimpikas <vasileios.bimpikas at analog.com>
Signed-off-by: Utsav Agarwal <utsav.agarwal at analog.com>
Signed-off-by: Arturs Artamonovs <arturs.artamonovs at analog.com>
Signed-off-by: Oliver Gaskell <Oliver.Gaskell at analog.com>
Signed-off-by: Nathan Barrett-Morrison <nathan.morrison at timesys.com>
---
Changes in v3:
- replace readw/writew with ioread16 and iowrite16 and friends
MAINTAINERS | 1 +
drivers/i2c/Kconfig | 7 +
drivers/i2c/Makefile | 1 +
drivers/i2c/adi_i2c.c | 386 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 395 insertions(+)
create mode 100644 drivers/i2c/adi_i2c.c
diff --git a/MAINTAINERS b/MAINTAINERS
index b57e2119679..f2638becc32 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -634,6 +634,7 @@ F: doc/device-tree-bindings/timer/adi,sc5xx-gptimer.yaml
F: drivers/clk/adi/
F: drivers/gpio/adp5588_gpio.c
F: drivers/gpio/gpio-adi-adsp.c
+F: drivers/i2c/adi_i2c.c
F: drivers/pinctrl/pinctrl-adi-adsp.c
F: drivers/serial/serial_adi_uart4.c
F: drivers/timer/adi_sc5xx_timer.c
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
index cdae6825736..46e76385961 100644
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -154,6 +154,13 @@ config SPL_DM_I2C_GPIO
bindings are supported.
Binding info: doc/device-tree-bindings/i2c/i2c-gpio.txt
+config SYS_I2C_ADI
+ bool "ADI I2C driver"
+ depends on DM_I2C && ARCH_SC5XX
+ help
+ Add support for the ADI (Analog Devices) I2C driver as used
+ in SC57X, SC58X, SC59X, SC59X_64.
+
config SYS_I2C_AT91
bool "Atmel I2C driver"
depends on DM_I2C && ARCH_AT91
diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index bebd728e7da..2713289f7db 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_$(XPL_)I2C_CROS_EC_TUNNEL) += cros_ec_tunnel.o
obj-$(CONFIG_$(XPL_)I2C_CROS_EC_LDO) += cros_ec_ldo.o
obj-$(CONFIG_$(XPL_)SYS_I2C_LEGACY) += i2c_core.o
+obj-$(CONFIG_SYS_I2C_ADI) += adi_i2c.o
obj-$(CONFIG_SYS_I2C_ASPEED) += ast_i2c.o
obj-$(CONFIG_SYS_I2C_AST2600) += ast2600_i2c.o
obj-$(CONFIG_SYS_I2C_AT91) += at91_i2c.o
diff --git a/drivers/i2c/adi_i2c.c b/drivers/i2c/adi_i2c.c
new file mode 100644
index 00000000000..4cddcfa6b7f
--- /dev/null
+++ b/drivers/i2c/adi_i2c.c
@@ -0,0 +1,386 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * (C) Copyright 2022 - Analog Devices, Inc.
+ *
+ * Written and/or maintained by Timesys Corporation
+ *
+ * Converted to driver model by Nathan Barrett-Morrison
+ *
+ * Contact: Nathan Barrett-Morrison <nathan.morrison at timesys.com>
+ * Contact: Greg Malysa <greg.malysa at timesys.com>
+ */
+
+#include <clk.h>
+#include <dm.h>
+#include <i2c.h>
+#include <mapmem.h>
+#include <linux/io.h>
+
+#define CLKLOW(x) ((x) & 0xFF) // Periods Clock Is Held Low
+#define CLKHI(y) (((y) & 0xFF) << 0x8) // Periods Clock Is High
+
+#define PRESCALE 0x007F // SCLKs Per Internal Time Reference (10MHz)
+#define TWI_ENA 0x0080 // TWI Enable
+#define SCCB 0x0200 // SCCB Compatibility Enable
+
+#define SEN 0x0001 // Slave Enable
+#define SADD_LEN 0x0002 // Slave Address Length
+#define STDVAL 0x0004 // Slave Transmit Data Valid
+#define TSC_NAK 0x0008 // NAK Generated At Conclusion Of Transfer
+#define GEN 0x0010 // General Call Adrress Matching Enabled
+
+#define SDIR 0x0001 // Slave Transfer Direction
+#define GCALL 0x0002 // General Call Indicator
+
+#define MEN 0x0001 // Master Mode Enable
+#define MADD_LEN 0x0002 // Master Address Length
+#define MDIR 0x0004 // Master Transmit Direction (RX/TX*)
+#define FAST 0x0008 // Use Fast Mode Timing Specs
+#define STOP 0x0010 // Issue Stop Condition
+#define RSTART 0x0020 // Repeat Start or Stop* At End Of Transfer
+#define DCNT 0x3FC0 // Data Bytes To Transfer
+#define SDAOVR 0x4000 // Serial Data Override
+#define SCLOVR 0x8000 // Serial Clock Override
+
+#define MPROG 0x0001 // Master Transfer In Progress
+#define LOSTARB 0x0002 // Lost Arbitration Indicator (Xfer Aborted)
+#define ANAK 0x0004 // Address Not Acknowledged
+#define DNAK 0x0008 // Data Not Acknowledged
+#define BUFRDERR 0x0010 // Buffer Read Error
+#define BUFWRERR 0x0020 // Buffer Write Error
+#define SDASEN 0x0040 // Serial Data Sense
+#define SCLSEN 0x0080 // Serial Clock Sense
+#define BUSBUSY 0x0100 // Bus Busy Indicator
+
+#define SINIT 0x0001 // Slave Transfer Initiated
+#define SCOMP 0x0002 // Slave Transfer Complete
+#define SERR 0x0004 // Slave Transfer Error
+#define SOVF 0x0008 // Slave Overflow
+#define MCOMP 0x0010 // Master Transfer Complete
+#define MERR 0x0020 // Master Transfer Error
+#define XMTSERV 0x0040 // Transmit FIFO Service
+#define RCVSERV 0x0080 // Receive FIFO Service
+
+#define XMTFLUSH 0x0001 // Transmit Buffer Flush
+#define RCVFLUSH 0x0002 // Receive Buffer Flush
+#define XMTINTLEN 0x0004 // Transmit Buffer Interrupt Length
+#define RCVINTLEN 0x0008 // Receive Buffer Interrupt Length
+
+#define XMTSTAT 0x0003 // Transmit FIFO Status
+#define XMT_EMPTY 0x0000 // Transmit FIFO Empty
+#define XMT_HALF 0x0001 // Transmit FIFO Has 1 Byte To Write
+#define XMT_FULL 0x0003 // Transmit FIFO Full (2 Bytes To Write)
+
+#define RCVSTAT 0x000C // Receive FIFO Status
+#define RCV_EMPTY 0x0000 // Receive FIFO Empty
+#define RCV_HALF 0x0004 // Receive FIFO Has 1 Byte To Read
+#define RCV_FULL 0x000C // Receive FIFO Full (2 Bytes To Read)
+
+/* Every register is 32bit aligned, but only 16bits in size */
+#define ureg(name) u16 name; u16 __pad_##name
+
+struct twi_regs {
+ ureg(clkdiv);
+ ureg(control);
+ ureg(slave_ctl);
+ ureg(slave_stat);
+ ureg(slave_addr);
+ ureg(master_ctl);
+ ureg(master_stat);
+ ureg(master_addr);
+ ureg(int_stat);
+ ureg(int_mask);
+ ureg(fifo_ctl);
+ ureg(fifo_stat);
+ u8 __pad[0x50];
+
+ ureg(xmt_data8);
+ ureg(xmt_data16);
+ ureg(rcv_data8);
+ ureg(rcv_data16);
+};
+
+#undef ureg
+
+/*
+ * The way speed is changed into duty often results in integer truncation
+ * with 50% duty, so we'll force rounding up to the next duty by adding 1
+ * to the max. In practice this will get us a speed of something like
+ * 385 KHz. The other limit is easy to handle as it is only 8 bits.
+ */
+#define I2C_SPEED_MAX 400000
+#define I2C_SPEED_TO_DUTY(speed) (5000000 / (speed))
+#define I2C_DUTY_MAX (I2C_SPEED_TO_DUTY(I2C_SPEED_MAX) + 1)
+#define I2C_DUTY_MIN 0xff /* 8 bit limited */
+
+#define I2C_M_COMBO 0x4
+#define I2C_M_STOP 0x2
+#define I2C_M_READ 0x1
+
+/*
+ * All transfers are described by this data structure
+ */
+struct adi_i2c_msg {
+ u8 flags;
+ u32 len; /* msg length */
+ u8 *buf; /* pointer to msg data */
+ u32 olen; /* addr length */
+ u8 *obuf; /* addr buffer */
+};
+
+struct adi_i2c_dev {
+ struct twi_regs __iomem *base;
+ u32 i2c_clk;
+ uint speed;
+};
+
+/* Allow msec timeout per ~byte transfer */
+#define I2C_TIMEOUT 10
+
+/**
+ * wait_for_completion - manage the actual i2c transfer
+ * @msg: the i2c msg
+ */
+static int wait_for_completion(struct twi_regs *twi, struct adi_i2c_msg *msg)
+{
+ u16 int_stat;
+ ulong timebase = get_timer(0);
+
+ do {
+ int_stat = ioread16(&twi->int_stat);
+
+ if (int_stat & XMTSERV) {
+ iowrite16(XMTSERV, &twi->int_stat);
+ if (msg->olen) {
+ iowrite16(*(msg->obuf++), &twi->xmt_data8);
+ --msg->olen;
+ } else if (!(msg->flags & I2C_M_COMBO) && msg->len) {
+ iowrite16(*(msg->buf++), &twi->xmt_data8);
+ --msg->len;
+ } else {
+ if (msg->flags & I2C_M_COMBO)
+ setbits_16(&twi->master_ctl, RSTART | MDIR);
+ else
+ setbits_16(&twi->master_ctl, STOP);
+ }
+ }
+ if (int_stat & RCVSERV) {
+ iowrite16(RCVSERV, &twi->int_stat);
+ if (msg->len) {
+ *(msg->buf++) = ioread16(&twi->rcv_data8);
+ --msg->len;
+ } else if (msg->flags & I2C_M_STOP) {
+ setbits_16(&twi->master_ctl, STOP);
+ }
+ }
+ if (int_stat & MERR) {
+ pr_err("%s: master transmit terror: %d\n", __func__,
+ ioread16(&twi->master_stat));
+ iowrite16(MERR, &twi->int_stat);
+ return -EIO;
+ }
+ if (int_stat & MCOMP) {
+ iowrite16(MCOMP, &twi->int_stat);
+ if (msg->flags & I2C_M_COMBO && msg->len) {
+ u16 mlen = min(msg->len, 0xffu) << 6;
+ clrsetbits_16(&twi->master_ctl, RSTART, mlen | MEN | MDIR);
+ } else {
+ break;
+ }
+ }
+
+ /* If we were able to do something, reset timeout */
+ if (int_stat)
+ timebase = get_timer(0);
+
+ } while (get_timer(timebase) < I2C_TIMEOUT);
+
+ return 0;
+}
+
+static int i2c_transfer(struct twi_regs *twi, u8 chip, u8 *offset,
+ int olen, u8 *buffer, int len, u8 flags)
+{
+ int ret;
+ u16 ctl;
+
+ struct adi_i2c_msg msg = {
+ .flags = flags | (len >= 0xff ? I2C_M_STOP : 0),
+ .buf = buffer,
+ .len = len,
+ .obuf = offset,
+ .olen = olen,
+ };
+
+ /* wait for things to settle */
+ while (ioread16(&twi->master_stat) & BUSBUSY)
+ if (!IS_ENABLED(CONFIG_SPL_BUILD) && ctrlc())
+ return -EINTR;
+
+ /* Set Transmit device address */
+ iowrite16(chip, &twi->master_addr);
+
+ /* Clear the FIFO before starting things */
+ iowrite16(XMTFLUSH | RCVFLUSH, &twi->fifo_ctl);
+ iowrite16(0, &twi->fifo_ctl);
+
+ /* Prime the pump */
+ if (msg.olen) {
+ len = (msg.flags & I2C_M_COMBO) ? msg.olen : msg.olen + len;
+ iowrite16(*(msg.obuf++), &twi->xmt_data8);
+ --msg.olen;
+ } else if (!(msg.flags & I2C_M_READ) && msg.len) {
+ iowrite16(*(msg.buf++), &twi->xmt_data8);
+ --msg.len;
+ }
+
+ /* clear int stat */
+ iowrite16(-1, &twi->master_stat);
+ iowrite16(-1, &twi->int_stat);
+ iowrite16(0, &twi->int_mask);
+
+ /* Master enable */
+ ctl = ioread16(&twi->master_ctl);
+ ctl = (ctl & FAST) | (min(len, 0xff) << 6) | MEN |
+ ((msg.flags & I2C_M_READ) ? MDIR : 0);
+ iowrite16(ctl, &twi->master_ctl);
+
+ /* Process the rest */
+ ret = wait_for_completion(twi, &msg);
+
+ clrbits_16(&twi->master_ctl, MEN);
+ clrbits_16(&twi->control, TWI_ENA);
+ setbits_16(&twi->control, TWI_ENA);
+ return ret;
+}
+
+static int adi_i2c_read(struct twi_regs *twi, u8 chip,
+ u8 *offset, int olen, u8 *buffer, int len)
+{
+ return i2c_transfer(twi, chip, offset, olen, buffer,
+ len, olen ? I2C_M_COMBO : I2C_M_READ);
+}
+
+static int adi_i2c_write(struct twi_regs *twi, u8 chip,
+ u8 *offset, int olen, u8 *buffer, int len)
+{
+ return i2c_transfer(twi, chip, offset, olen, buffer, len, 0);
+}
+
+static int adi_i2c_set_bus_speed(struct udevice *bus, uint speed)
+{
+ struct adi_i2c_dev *dev = dev_get_priv(bus);
+ struct twi_regs *twi = dev->base;
+ u16 clkdiv = I2C_SPEED_TO_DUTY(speed);
+
+ /* Set TWI interface clock */
+ if (clkdiv < I2C_DUTY_MAX || clkdiv > I2C_DUTY_MIN)
+ return -1;
+ clkdiv = (clkdiv << 8) | (clkdiv & 0xff);
+ iowrite16(clkdiv, &twi->clkdiv);
+
+ /* Don't turn it on */
+ iowrite16(speed > 100000 ? FAST : 0, &twi->master_ctl);
+
+ return 0;
+}
+
+static int adi_i2c_of_to_plat(struct udevice *bus)
+{
+ struct adi_i2c_dev *dev = dev_get_priv(bus);
+ struct clk clock;
+ u32 ret;
+
+ dev->base = map_sysmem(dev_read_addr(bus), sizeof(struct twi_regs));
+
+ if (!dev->base)
+ return -ENOMEM;
+
+ dev->speed = dev_read_u32_default(bus, "clock-frequency",
+ I2C_SPEED_FAST_RATE);
+
+ ret = clk_get_by_name(bus, "i2c", &clock);
+ if (ret < 0)
+ printf("%s: Can't get I2C clk: %d\n", __func__, ret);
+ else
+ dev->i2c_clk = clk_get_rate(&clock);
+
+ return 0;
+}
+
+static int adi_i2c_probe_chip(struct udevice *bus, u32 chip_addr,
+ u32 chip_flags)
+{
+ struct adi_i2c_dev *dev = dev_get_priv(bus);
+ u8 byte;
+
+ return adi_i2c_read(dev->base, chip_addr, NULL, 0, &byte, 1);
+}
+
+static int adi_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
+{
+ struct adi_i2c_dev *dev = dev_get_priv(bus);
+ struct i2c_msg *dmsg, *omsg, dummy;
+
+ memset(&dummy, 0, sizeof(struct i2c_msg));
+
+ /*
+ * We expect either two messages (one with an offset and one with the
+ * actual data) or one message (just data)
+ */
+ if (nmsgs > 2 || nmsgs == 0) {
+ debug("%s: Only one or two messages are supported.", __func__);
+ return -EINVAL;
+ }
+
+ omsg = nmsgs == 1 ? &dummy : msg;
+ dmsg = nmsgs == 1 ? msg : msg + 1;
+
+ if (dmsg->flags & I2C_M_RD)
+ return adi_i2c_read(dev->base, dmsg->addr, omsg->buf, omsg->len,
+ dmsg->buf, dmsg->len);
+ else
+ return adi_i2c_write(dev->base, dmsg->addr, omsg->buf, omsg->len,
+ dmsg->buf, dmsg->len);
+}
+
+int adi_i2c_probe(struct udevice *bus)
+{
+ struct adi_i2c_dev *dev = dev_get_priv(bus);
+ struct twi_regs *twi = dev->base;
+
+ u16 prescale = ((dev->i2c_clk / 1000 / 1000 + 5) / 10) & 0x7F;
+
+ /* Set TWI internal clock as 10MHz */
+ iowrite16(prescale, &twi->control);
+
+ /* Set TWI interface clock as specified */
+ adi_i2c_set_bus_speed(bus, dev->speed);
+
+ /* Enable it */
+ iowrite16(TWI_ENA | prescale, &twi->control);
+
+ return 0;
+}
+
+static const struct dm_i2c_ops adi_i2c_ops = {
+ .xfer = adi_i2c_xfer,
+ .probe_chip = adi_i2c_probe_chip,
+ .set_bus_speed = adi_i2c_set_bus_speed,
+};
+
+static const struct udevice_id adi_i2c_ids[] = {
+ { .compatible = "adi-i2c", },
+ { /* sentinel */ }
+};
+
+U_BOOT_DRIVER(i2c_adi) = {
+ .name = "i2c_adi",
+ .id = UCLASS_I2C,
+ .of_match = adi_i2c_ids,
+ .probe = adi_i2c_probe,
+ .of_to_plat = adi_i2c_of_to_plat,
+ .priv_auto = sizeof(struct adi_i2c_dev),
+ .ops = &adi_i2c_ops,
+ .flags = DM_FLAG_PRE_RELOC,
+};
--
2.45.2
More information about the U-Boot
mailing list