summaryrefslogtreecommitdiffstats
path: root/drivers/i2c
diff options
context:
space:
mode:
authorTin Huynh <tnhuynh@apm.com>2016-11-10 09:56:33 +0700
committerWolfram Sang <wsa@the-dreams.de>2016-11-18 02:06:41 +0100
commitc3ae106050b949d6c776c5434046c888a5a6298a (patch)
tree840a28fc29aa05b1711e11c79acee3ad8be366cc /drivers/i2c
parent379883cc67d890e0412d6e6c952d7eb0614b915a (diff)
downloadop-kernel-dev-c3ae106050b949d6c776c5434046c888a5a6298a.zip
op-kernel-dev-c3ae106050b949d6c776c5434046c888a5a6298a.tar.gz
i2c: designware: Implement support for SMBus block read and write
Free and Open IPMI use SMBUS BLOCK Read/Write to support SSIF protocol. However, I2C Designware Core Driver doesn't handle the case at the moment. The below patch supports this feature. Signed-off-by: Tin Huynh <tnhuynh@apm.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-designware-core.c46
-rw-r--r--drivers/i2c/busses/i2c-designware-pcidrv.c1
-rw-r--r--drivers/i2c/busses/i2c-designware-platdrv.c1
3 files changed, 45 insertions, 3 deletions
diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index 11e866d..4f56328 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -554,6 +554,8 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
intr_mask = DW_IC_INTR_DEFAULT_MASK;
for (; dev->msg_write_idx < dev->msgs_num; dev->msg_write_idx++) {
+ u32 flags = msgs[dev->msg_write_idx].flags;
+
/*
* if target address has changed, we need to
* reprogram the target address in the i2c
@@ -599,8 +601,15 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
* detected from the registers so we set it always
* when writing/reading the last byte.
*/
+
+ /*
+ * i2c-core.c always sets the buffer length of
+ * I2C_FUNC_SMBUS_BLOCK_DATA to 1. The length will
+ * be adjusted when receiving the first byte.
+ * Thus we can't stop the transaction here.
+ */
if (dev->msg_write_idx == dev->msgs_num - 1 &&
- buf_len == 1)
+ buf_len == 1 && !(flags & I2C_M_RECV_LEN))
cmd |= BIT(9);
if (need_restart) {
@@ -625,7 +634,12 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
dev->tx_buf = buf;
dev->tx_buf_len = buf_len;
- if (buf_len > 0) {
+ /*
+ * Because we don't know the buffer length in the
+ * I2C_FUNC_SMBUS_BLOCK_DATA case, we can't stop
+ * the transaction here.
+ */
+ if (buf_len > 0 || flags & I2C_M_RECV_LEN) {
/* more bytes to be written */
dev->status |= STATUS_WRITE_IN_PROGRESS;
break;
@@ -646,6 +660,24 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
dw_writel(dev, intr_mask, DW_IC_INTR_MASK);
}
+static u8
+i2c_dw_recv_len(struct dw_i2c_dev *dev, u8 len)
+{
+ struct i2c_msg *msgs = dev->msgs;
+ u32 flags = msgs[dev->msg_read_idx].flags;
+
+ /*
+ * Adjust the buffer length and mask the flag
+ * after receiving the first byte.
+ */
+ len += (flags & I2C_CLIENT_PEC) ? 2 : 1;
+ dev->tx_buf_len = len - min_t(u8, len, dev->rx_outstanding);
+ msgs[dev->msg_read_idx].len = len;
+ msgs[dev->msg_read_idx].flags &= ~I2C_M_RECV_LEN;
+
+ return len;
+}
+
static void
i2c_dw_read(struct dw_i2c_dev *dev)
{
@@ -670,7 +702,15 @@ i2c_dw_read(struct dw_i2c_dev *dev)
rx_valid = dw_readl(dev, DW_IC_RXFLR);
for (; len > 0 && rx_valid > 0; len--, rx_valid--) {
- *buf++ = dw_readl(dev, DW_IC_DATA_CMD);
+ u32 flags = msgs[dev->msg_read_idx].flags;
+
+ *buf = dw_readl(dev, DW_IC_DATA_CMD);
+ /* Ensure length byte is a valid value */
+ if (flags & I2C_M_RECV_LEN &&
+ *buf <= I2C_SMBUS_BLOCK_MAX && *buf > 0) {
+ len = i2c_dw_recv_len(dev, *buf);
+ }
+ buf++;
dev->rx_outstanding--;
}
diff --git a/drivers/i2c/busses/i2c-designware-pcidrv.c b/drivers/i2c/busses/i2c-designware-pcidrv.c
index 96f8230..8ffe2da 100644
--- a/drivers/i2c/busses/i2c-designware-pcidrv.c
+++ b/drivers/i2c/busses/i2c-designware-pcidrv.c
@@ -75,6 +75,7 @@ struct dw_pci_controller {
I2C_FUNC_SMBUS_BYTE | \
I2C_FUNC_SMBUS_BYTE_DATA | \
I2C_FUNC_SMBUS_WORD_DATA | \
+ I2C_FUNC_SMBUS_BLOCK_DATA | \
I2C_FUNC_SMBUS_I2C_BLOCK)
/* Merrifield HCNT/LCNT/SDA hold time */
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 0b42a12..886fb62 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -220,6 +220,7 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
I2C_FUNC_SMBUS_BYTE |
I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_WORD_DATA |
+ I2C_FUNC_SMBUS_BLOCK_DATA |
I2C_FUNC_SMBUS_I2C_BLOCK;
dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
OpenPOWER on IntegriCloud