Read and Write callbacks for PCI1XXXX I2C adapter is added.
Signed-off-by: LakshmiPraveen Kopparthi <LakshmiPraveen.Kopparthi@xxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-mchp-pci1xxxx.c | 485 +++++++++++++++++++++++++
1 file changed, 485 insertions(+)
diff --git a/drivers/i2c/busses/i2c-mchp-pci1xxxx.c b/drivers/i2c/busses/i2c-mchp-pci1xxxx.c
index 5b51f20fe98e..0ac05a65a3e4 100644
--- a/drivers/i2c/busses/i2c-mchp-pci1xxxx.c
+++ b/drivers/i2c/busses/i2c-mchp-pci1xxxx.c
@@ -232,6 +232,147 @@ struct pci1xxxx_i2c {
u32 flags;
};
+static void pci1xxxx_i2c_send_start(struct pci1xxxx_i2c *i2c)
+{
+ u8 regval;
+
+ regval = readb(i2c->i2c_base + SMB_CORE_CMD_REG_OFF1);
+ regval |= SMB_CORE_CMD_START;
+ writeb(regval, (i2c->i2c_base + SMB_CORE_CMD_REG_OFF1));
+}
+
+static void pci1xxxx_i2c_send_stop(struct pci1xxxx_i2c *i2c)
+{
+ u8 regval;
+
+ regval = readb(i2c->i2c_base + SMB_CORE_CMD_REG_OFF1);
+ regval |= SMB_CORE_CMD_STOP;
+ writeb(regval, (i2c->i2c_base + SMB_CORE_CMD_REG_OFF1));
+}
+
+/*
+ * when accessing the core control reg, we should not do a read modified write
+ * as there are write '1' to clear bits. Hence do a write with the specific
+ * bits that needs to be set
+ */
+static void pci1xxxx_i2c_set_clear_FW_ACK(struct pci1xxxx_i2c *i2c, bool set)
+{
+ u8 regval;
+
+ if (set)
+ regval = SMB_CORE_CTRL_FW_ACK | SMB_CORE_CTRL_ESO;
+ else
+ regval = SMB_CORE_CTRL_ESO;
+
+ writeb(regval, (i2c->i2c_base + SMB_CORE_CTRL_REG_OFF));
+}
+
+static void pci1xxxx_i2c_buffer_write(struct pci1xxxx_i2c *i2c, u8 slaveaddr,
+ u8 transferlen, unsigned char *buf)
+{
+ if (slaveaddr) {
+ writeb(slaveaddr, i2c->i2c_base + SMBUS_MST_BUF);
+ if (buf)
+ memcpy_toio((i2c->i2c_base + SMBUS_MST_BUF + 1), buf, transferlen);
+ } else {
+ if (buf)
+ memcpy_toio((i2c->i2c_base + SMBUS_MST_BUF), buf, transferlen);
+ }
+}
+
+/*
+ * when accessing the core control reg, we should not do a read modified write
+ * as there are write '1' to clear bits. Hence do a write with the
+ * specific bits that needs to be set
+ */
+static void pci1xxxx_i2c_enable_ESO(struct pci1xxxx_i2c *i2c)
+{
+ writeb(SMB_CORE_CTRL_ESO, (i2c->i2c_base + SMB_CORE_CTRL_REG_OFF));
+}
+
+static void pci1xxxx_i2c_reset_counters(struct pci1xxxx_i2c *i2c)
+{
+ u8 regval;
+
+ regval = readb(i2c->i2c_base + SMBUS_CONTROL_REG_OFF);
+ regval |= CTL_RESET_COUNTERS;
+ writeb(regval, (i2c->i2c_base + SMBUS_CONTROL_REG_OFF));
+}
+
+static void pci1xxxx_i2c_set_transfer_dir(struct pci1xxxx_i2c *i2c, u8 direction)
+{
+ u8 regval;
+
+ regval = readb(i2c->i2c_base + SMBUS_CONTROL_REG_OFF);
+ if (direction == I2C_DIR_WRITE)
+ regval &= ~CTL_TRANSFER_DIR;
+ else
+ regval |= CTL_TRANSFER_DIR;
+
+ writeb(regval, (i2c->i2c_base + SMBUS_CONTROL_REG_OFF));
+}
+
+static void pci1xxxx_i2c_set_mcu_count(struct pci1xxxx_i2c *i2c, u8 count)
+{
+ writeb(count, (i2c->i2c_base + SMBUS_MCU_COUNTER_REG_OFF));
+}
+
+static void pci1xxxx_i2c_set_read_count(struct pci1xxxx_i2c *i2c, u8 readcount)
+{
+ writeb(readcount, (i2c->i2c_base + SMB_CORE_CMD_REG_OFF3));
+}
+
+static void pci1xxxx_i2c_set_write_count(struct pci1xxxx_i2c *i2c, u8 writecount)
+{
+ writeb(writecount, (i2c->i2c_base + SMB_CORE_CMD_REG_OFF2));
+}
+
+static void pci1xxxx_i2c_set_proceed(struct pci1xxxx_i2c *i2c)
+{
+ u8 regval;
+
+ regval = readb(i2c->i2c_base + SMB_CORE_CMD_REG_OFF0);
+ regval |= SMB_CORE_CMD_M_PROCEED;
+ writeb(regval, (i2c->i2c_base + SMB_CORE_CMD_REG_OFF0));
+}
+
+static void pci1xxxx_i2c_set_DMA_run(struct pci1xxxx_i2c *i2c)
+{
+ u8 regval;
+
+ regval = readb(i2c->i2c_base + SMBUS_CONTROL_REG_OFF);
+ regval |= CTL_RUN;
+ writeb(regval, (i2c->i2c_base + SMBUS_CONTROL_REG_OFF));
+}
+
+static void pci1xxxx_i2c_set_mrun(struct pci1xxxx_i2c *i2c)
+{
+ u8 regval;
+
+ regval = readb(i2c->i2c_base + SMB_CORE_CMD_REG_OFF0);
+ regval |= SMB_CORE_CMD_M_RUN;
+ writeb(regval, (i2c->i2c_base + SMB_CORE_CMD_REG_OFF0));
+}
+
+static void pci1xxxx_i2c_start_DMA(struct pci1xxxx_i2c *i2c)
+{
+ pci1xxxx_i2c_set_DMA_run(i2c);
+ pci1xxxx_i2c_set_mrun(i2c);
+ pci1xxxx_i2c_set_proceed(i2c);
+}
+
+static void pci1xxxx_i2c_config_asr(struct pci1xxxx_i2c *i2c, bool enable)
+{
+ u8 regval;
+
+ regval = readb(i2c->i2c_base + SMB_CORE_CONFIG_REG1);
+ if (enable)
+ regval |= SMB_CONFIG1_ASR;
+ else
+ regval &= ~SMB_CONFIG1_ASR;
+ writeb(regval, i2c->i2c_base + SMB_CORE_CONFIG_REG1);
+}
+
static irqreturn_t pci1xxxx_i2c_isr(int irq, void *dev)
{
struct pci1xxxx_i2c *i2c = dev;
@@ -284,6 +425,47 @@ static irqreturn_t pci1xxxx_i2c_isr(int irq, void *dev)
return IRQ_NONE;
}
+static void pci1xxxx_i2c_set_count(struct pci1xxxx_i2c *i2c, u8 mcucount,
+ u8 writecount, u8 readcount)
+{
+ pci1xxxx_i2c_set_mcu_count(i2c, mcucount);
+ pci1xxxx_i2c_set_write_count(i2c, writecount);
+ pci1xxxx_i2c_set_read_count(i2c, readcount);
+}
+
+static void pci1xxxx_i2c_set_readm(struct pci1xxxx_i2c *i2c, bool enable)
+{
+ u8 regval;
+
+ regval = readb(i2c->i2c_base + SMB_CORE_CMD_REG_OFF1);
+ if (enable)
+ regval |= SMB_CORE_CMD_READM;
+ else
+ regval &= ~SMB_CORE_CMD_READM;
+
+ writeb(regval, (i2c->i2c_base + SMB_CORE_CMD_REG_OFF1));
+}
+
+static void pci1xxxx_ack_nw_layer_intr(struct pci1xxxx_i2c *i2c,
+ u8 ack_intr_msk)
+{
+ writeb(ack_intr_msk, (i2c->i2c_base + SMBUS_INTR_STAT_REG_OFF));
+}
+
+static void pci1xxxx_config_nw_layer_intr(struct pci1xxxx_i2c *i2c,
+ u8 intr_msk, bool enable)
+{
+ u8 regval;
+
+ regval = readb(i2c->i2c_base + SMBUS_INTR_MSK_REG_OFF);
+ if (enable)
+ regval &= ~(intr_msk);
+ else
+ regval |= intr_msk;
+
+ writeb(regval, (i2c->i2c_base + SMBUS_INTR_MSK_REG_OFF));
+}
+
static void pci1xxxx_i2c_config_padctrl(struct pci1xxxx_i2c *i2c, bool enable)
{
u8 regval;
@@ -428,6 +610,308 @@ static void pci1xxxx_i2c_init(struct pci1xxxx_i2c *i2c)
pci1xxxx_i2c_configure_core_reg(i2c, true);
}
+static void pci1xxxx_i2c_clear_flags(struct pci1xxxx_i2c *i2c)
+{
+ u8 regval;
+ /* Reset the internal buffer counters */
+ pci1xxxx_i2c_reset_counters(i2c);
+
+ /* Clear low level interrupts */
+ regval = (COMPLETION_MNAKX | COMPLETION_IDLE | COMPLETION_MDONE);
+ writeb(regval, i2c->i2c_base + SMB_CORE_COMPLETION_REG_OFF3);
+
+ reinit_completion(&i2c->i2c_xfer_done);
+ pci1xxxx_ack_nw_layer_intr(i2c, ALL_NW_LAYER_INTERRUPTS);
+
+ pci1xxxx_ack_high_level_intr(i2c, ALL_HIGH_LAYER_INTR);
+}
+
+static int pci1xxxx_i2c_read(struct pci1xxxx_i2c *i2c, u8 slaveaddr,
+ unsigned char *buf, u16 total_len)
+{
+ unsigned long time_left;
+ u16 remainingbytes;
+ u8 transferlen;
+ int retval = 0;
+ u8 read_count;
+ u32 regval;
+ u16 count;
+
+ /* Enable I2C master by setting the ESO bit in the CONTROL REG */
+ pci1xxxx_i2c_enable_ESO(i2c);
+
+ pci1xxxx_i2c_clear_flags(i2c);
+
+ pci1xxxx_config_nw_layer_intr(i2c, INTR_MSK_DMA_TERM, true);
+
+ pci1xxxx_i2c_config_high_level_intr(i2c, (I2C_BUF_MSTR_INTR_MASK),
+ true);
+
+ /*
+ * The i2c transfer could be for more thatn 128 bytes. Our Core is
+ * capable of only sending 128 at a time.
+ * As for as the I2C read is concerned, initailly send the
+ * read slave address along with the number of bytes to read in
+ * ReadCount. After sending the salve address the interrupt
+ * is generated. On seeing the ACK for the slave address, reverse the
+ * buffer direction and run the DMA to initiate Read from slave
+ */
+ for (count = 0; count < total_len; count += transferlen) {
+ /*
+ * before start of any transaction clear the existing
+ * START/STOP conditions
+ */
+ writeb(0x00, (i2c->i2c_base + SMB_CORE_CMD_REG_OFF1));
+
+ remainingbytes = total_len - count;
+
+ transferlen = min(remainingbytes, (u16)(SMBUS_MAST_BUF_MAX_SIZE));
+
+ /*
+ * See if this is last chunk in the transaction. IN that case
+ * send a STOP at the end.
+ * Also in case of reads > BUF_SIZE, for the first read,
+ * we should not send NACK for the last byte.
+ * Hence a bit FW_ACK is set for those.
+ * For the last chunk NACK should be sent.
+ * Hence FW_ACK is cleared for that.
+ * Send STOP only when I2C_FLAGS_STOP bit is set in the flags
+ * and only for the last transaction.
+ */
+
+ if (transferlen < SMBUS_MAST_BUF_MAX_SIZE) {
+ if (i2c->flags & I2C_FLAGS_STOP) {
+ pci1xxxx_i2c_set_clear_FW_ACK(i2c, false);
+ pci1xxxx_i2c_send_stop(i2c);
+ } else {
+ pci1xxxx_i2c_set_clear_FW_ACK(i2c, true);
+ }
+ }
+
+ /* if it is the starting of the transaction send START */
+ if (count == 0) {
+ pci1xxxx_i2c_set_transfer_dir(i2c, I2C_DIR_WRITE);
+
+ pci1xxxx_i2c_send_start(i2c);
+
+ /* write I2c buffer with just the slave addr */
+ pci1xxxx_i2c_buffer_write(i2c, slaveaddr, 0, NULL);
+
+ /* Set the count. Readcount is the transfer bytes */
+ pci1xxxx_i2c_set_count(i2c, 1, 1, transferlen);
+
+ /*
+ * Set the Auto_start_read bit so that the HW itself
+ * will take care of the read phase.
+ */
+
+ pci1xxxx_i2c_config_asr(i2c, true);
+
+ if (i2c->flags & I2C_FLAGS_SMB_BLK_READ)
+ pci1xxxx_i2c_set_readm(i2c, true);
+
+ } else {
+ /* Set the count */
+ pci1xxxx_i2c_set_count(i2c, 0, 0, transferlen);
+
+ pci1xxxx_i2c_config_asr(i2c, false);
+
+ pci1xxxx_i2c_clear_flags(i2c);
+
+ pci1xxxx_i2c_set_transfer_dir(i2c, I2C_DIR_READ);
+ }
+
+ /* Start the DMA */
+ pci1xxxx_i2c_start_DMA(i2c);
+
+ /* wait for the DMA_TERM interrupt */
+ time_left = wait_for_completion_timeout
+ (&i2c->i2c_xfer_done,
+ PCI1XXXX_I2C_TIMEOUT);
+ if (time_left == 0) {
+ /* Reset the I2C core to release the bus lock */
+ pci1xxxx_i2c_init(i2c);
+ retval = -ETIMEDOUT;
+ goto cleanup;
+ }
+
+ /* Read the completion reg to know the reason for DMA_TERM */
+ regval = readb(i2c->i2c_base + SMB_CORE_COMPLETION_REG_OFF3);
+ /* Slave did not respond */
+ if (regval & COMPLETION_MNAKX) {
+ writeb(COMPLETION_MNAKX, (i2c->i2c_base +
+ SMB_CORE_COMPLETION_REG_OFF3));
+ retval = -ETIMEDOUT;
+ goto cleanup;
+ }
+
+ if (i2c->flags & I2C_FLAGS_SMB_BLK_READ) {
+ buf[0] = readb(i2c->i2c_base +
+ SMBUS_MST_BUF);
+ read_count = buf[0];
+ memcpy_fromio(&buf[1], (i2c->i2c_base +
+ SMBUS_MST_BUF + 1),
+ read_count);
+ } else {
+ memcpy_fromio(&buf[count], (i2c->i2c_base +
+ SMBUS_MST_BUF), transferlen);
+ }
+ }
+
+cleanup:
+ /* Disable all the interrupts */
+ pci1xxxx_config_nw_layer_intr(i2c, INTR_MSK_DMA_TERM, false);
+ pci1xxxx_i2c_config_high_level_intr(i2c, (I2C_BUF_MSTR_INTR_MASK),
+ false);
+ pci1xxxx_i2c_config_asr(i2c, false);
+ return retval;
+}
+
+static int pci1xxxx_i2c_write(struct pci1xxxx_i2c *i2c, u8 slaveaddr,
+ unsigned char *buf, u16 total_len)
+{
+ unsigned long time_left;
+ u16 remainingbytes;
+ u8 actualwritelen;
+ u8 transferlen;
+ int retval = 0;
+ u32 regval;
+ u16 count;
+
+ /* Enable I2C master by setting the ESO bit in the CONTROL REG */
+ pci1xxxx_i2c_enable_ESO(i2c);
+
+ /* Set the Buffer direction */
+ pci1xxxx_i2c_set_transfer_dir(i2c, I2C_DIR_WRITE);
+
+ pci1xxxx_config_nw_layer_intr(i2c, INTR_MSK_DMA_TERM, true);
+
+ pci1xxxx_i2c_config_high_level_intr(i2c, (I2C_BUF_MSTR_INTR_MASK),
+ true);
+
+ /*
+ * The i2c transfer could be for more thatn 128 bytes. Our Core is
+ * capable of only sending 128 at a time.
+ */
+ for (count = 0; count < total_len; count += transferlen) {
+ /*
+ * before start of any transaction clear the existing
+ * START/STOP conditions
+ */
+ writeb(0x00, (i2c->i2c_base + SMB_CORE_CMD_REG_OFF1));
+
+ pci1xxxx_i2c_clear_flags(i2c);
+
+ remainingbytes = total_len - count;
+ /* if it is the starting of the transaction send START */
+ if (count == 0) {
+ pci1xxxx_i2c_send_start(i2c);
+
+ /* -1 for the slave address */
+ transferlen = min((u16)(SMBUS_MAST_BUF_MAX_SIZE - 1),
+ remainingbytes);
+ pci1xxxx_i2c_buffer_write(i2c, slaveaddr,
+ transferlen, &buf[count]);
+
+ /*
+ * the actual number of bytes written on the I2C bus
+ * is including the slave address
+ */
+ actualwritelen = transferlen + 1;
+
+ } else {
+ transferlen = min((u16)(SMBUS_MAST_BUF_MAX_SIZE),
+ remainingbytes);
+ pci1xxxx_i2c_buffer_write(i2c, 0x00, transferlen,
+ &buf[count]);
+ actualwritelen = transferlen;
+ }
+
+ pci1xxxx_i2c_set_count(i2c, actualwritelen,
+ actualwritelen, 0x00);
+
+ /*
+ * Send STOP only when I2C_FLAGS_STOP bit is set in the flags and
+ * only for the last transaction.
+ */
+
+ if (remainingbytes <= transferlen && (i2c->flags &
+ I2C_FLAGS_STOP))
+ pci1xxxx_i2c_send_stop(i2c);
+
+ pci1xxxx_i2c_start_DMA(i2c);
+
+ /*
+ * wait for the DMA_TERM interrupt and if the timer expires, it means
+ * the transaction has failed due to some bus lock as we dint get
+ * the interrupt
+ */
+ time_left = wait_for_completion_timeout
+ (&i2c->i2c_xfer_done, PCI1XXXX_I2C_TIMEOUT);
+
+ if (time_left == 0) {
+ /* Reset the I2C core to release the bus lock */
+ pci1xxxx_i2c_init(i2c);
+ retval = -ETIMEDOUT;
+ goto cleanup;
+ }
+
+ regval = readb(i2c->i2c_base + SMB_CORE_COMPLETION_REG_OFF3);
+ if (regval & COMPLETION_MNAKX) {
+ writeb(COMPLETION_MNAKX, (i2c->i2c_base +
+ SMB_CORE_COMPLETION_REG_OFF3));
+ retval = -ETIMEDOUT;
+ goto cleanup;
+ }
+ }
+cleanup:
+ /* Disable all the interrupts */
+ pci1xxxx_config_nw_layer_intr(i2c, INTR_MSK_DMA_TERM, false);
+ pci1xxxx_i2c_config_high_level_intr(i2c, (I2C_BUF_MSTR_INTR_MASK),
+ false);
+
+ return retval;
+}
+
+static int pci1xxxx_i2c_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ struct pci1xxxx_i2c *i2c = i2c_get_adapdata(adap);
+ u8 slaveaddr;
+ int retval;
+ u32 i;
+
+ for (i = 0; i < num; i++) {
+ slaveaddr = i2c_8bit_addr_from_msg(&msgs[i]);
+
+ /*
+ * Send STOP if it is the Last of the transfer or
+ * if the I2C_M_STOP flag is set
+ */
+ if ((i == (num - 1)) || (msgs[i].flags & I2C_M_STOP))
+ i2c->flags |= I2C_FLAGS_STOP;
+ else
+ i2c->flags &= ~I2C_FLAGS_STOP;
+
+ /* When the command is a block read command */
+ if (msgs[i].flags & I2C_M_RECV_LEN)
+ i2c->flags |= I2C_FLAGS_SMB_BLK_READ;
+ else
+ i2c->flags &= ~I2C_FLAGS_SMB_BLK_READ;
+
+ if (msgs[i].flags & I2C_M_RD)
+ retval = pci1xxxx_i2c_read(i2c, slaveaddr,
+ msgs[i].buf, msgs[i].len);
+ else
+ retval = pci1xxxx_i2c_write(i2c, slaveaddr,
+ msgs[i].buf, msgs[i].len);
+
+ if (retval < 0)
+ return retval;
+ }
+ return num;
+}
+
/*
* We could have used I2C_FUNC_SMBUS_EMUL but that includes
* SMBUS_QUICK as well.We dnt support SMBUS_QUICK hence the
@@ -448,6 +932,7 @@ static u32 pci1xxxx_i2c_get_funcs(struct i2c_adapter *adap)
}
static const struct i2c_algorithm pci1xxxx_i2c_algo = {
+ .master_xfer = pci1xxxx_i2c_xfer,
.functionality = pci1xxxx_i2c_get_funcs,
};
--
2.25.1
