* [PATCH v11 1/2] i2c: octeon: refactor common i2c operations
2025-01-20 2:33 [PATCH v11 0/2] i2c: octeon: Add block-mode r/w Aryan Srivastava
@ 2025-01-20 2:33 ` Aryan Srivastava
2025-01-20 2:33 ` [PATCH v11 2/2] i2c: octeon: Add block-mode " Aryan Srivastava
` (2 subsequent siblings)
3 siblings, 0 replies; 7+ messages in thread
From: Aryan Srivastava @ 2025-01-20 2:33 UTC (permalink / raw)
To: Andi Shyti, Markus Elfring
Cc: linux-i2c, linux-kernel, Aryan Srivastava, Robert Richter
Refactor the current implementation of the high-level composite read and
write operations in preparation of the addition of block-mode read/write
operations.
The sending of the i2c command is generic and will apply for both the
block-mode and non-block-mode ops. Extract this from the current hlc
ops, and place into a generic function, octeon_i2c_hlc_cmd_send.
The considerations made for extended addresses in the command
construction are almost common for all cases, extract these into
octeon_i2c_hlc_ext. There is one difference between the extended read
and write cases. When performing extended read or writes the SW_TWSI_EXT
must be written with an extended internal address, but the data field is
only filled in the write case (read back in read case). This results in
the original code block for the read case immediately writing this
register, while the write case fills in any data and then writes the
register. To create a common block of code for both processes remove the
SW_TWSI_EXT write from within the code block and instead in it's place a
variable is set, set_ext, which is returned and used as a condition to
do the register write, in the read command case.
There are parts of the commands construction which are common (only in
the read case), extract this and place into generic function
octeon_i2c_hlc_read_cmd. This function also reads the return from
octeon_i2c_hlc_ext and completes the write to SW_TWSI_EXT if required.
The write commands cannot be made entirely into common code as there are
distinct differences in the block mode and non-block-mode process.
Particularly the writing of data into the buffer.
Signed-off-by: Aryan Srivastava <aryan.srivastava@alliedtelesis.co.nz>
---
drivers/i2c/busses/i2c-octeon-core.c | 86 ++++++++++++++++------------
1 file changed, 49 insertions(+), 37 deletions(-)
diff --git a/drivers/i2c/busses/i2c-octeon-core.c b/drivers/i2c/busses/i2c-octeon-core.c
index 16cc34a0526e..3fbc828508ab 100644
--- a/drivers/i2c/busses/i2c-octeon-core.c
+++ b/drivers/i2c/busses/i2c-octeon-core.c
@@ -498,6 +498,50 @@ static int octeon_i2c_hlc_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
return ret;
}
+/* Process hlc transaction */
+static int octeon_i2c_hlc_cmd_send(struct octeon_i2c *i2c, u64 cmd)
+{
+ octeon_i2c_hlc_int_clear(i2c);
+ octeon_i2c_writeq_flush(cmd, i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
+
+ return octeon_i2c_hlc_wait(i2c);
+}
+
+/* Generic consideration for extended internal addresses in i2c hlc r/w ops */
+static bool octeon_i2c_hlc_ext(struct octeon_i2c *i2c, struct i2c_msg msg, u64 *cmd_in, u64 *ext)
+{
+ bool set_ext = false;
+ u64 cmd = 0;
+
+ if (msg.flags & I2C_M_TEN)
+ cmd |= SW_TWSI_OP_10_IA;
+ else
+ cmd |= SW_TWSI_OP_7_IA;
+
+ if (msg.len == 2) {
+ cmd |= SW_TWSI_EIA;
+ *ext = (u64)msg.buf[0] << SW_TWSI_IA_SHIFT;
+ cmd |= (u64)msg.buf[1] << SW_TWSI_IA_SHIFT;
+ set_ext = true;
+ } else {
+ cmd |= (u64)msg.buf[0] << SW_TWSI_IA_SHIFT;
+ }
+
+ *cmd_in |= cmd;
+ return set_ext;
+}
+
+/* Construct and send i2c transaction core cmd for read ops */
+static int octeon_i2c_hlc_read_cmd(struct octeon_i2c *i2c, struct i2c_msg msg, u64 cmd)
+{
+ u64 ext = 0;
+
+ if (octeon_i2c_hlc_ext(i2c, msg, &cmd, &ext))
+ octeon_i2c_writeq_flush(ext, i2c->twsi_base + OCTEON_REG_SW_TWSI_EXT(i2c));
+
+ return octeon_i2c_hlc_cmd_send(i2c, cmd);
+}
+
/* high-level-controller composite write+read, msg0=addr, msg1=data */
static int octeon_i2c_hlc_comp_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
{
@@ -512,26 +556,8 @@ static int octeon_i2c_hlc_comp_read(struct octeon_i2c *i2c, struct i2c_msg *msgs
/* A */
cmd |= (u64)(msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
- if (msgs[0].flags & I2C_M_TEN)
- cmd |= SW_TWSI_OP_10_IA;
- else
- cmd |= SW_TWSI_OP_7_IA;
-
- if (msgs[0].len == 2) {
- u64 ext = 0;
-
- cmd |= SW_TWSI_EIA;
- ext = (u64)msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
- cmd |= (u64)msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
- octeon_i2c_writeq_flush(ext, i2c->twsi_base + OCTEON_REG_SW_TWSI_EXT(i2c));
- } else {
- cmd |= (u64)msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
- }
-
- octeon_i2c_hlc_int_clear(i2c);
- octeon_i2c_writeq_flush(cmd, i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
-
- ret = octeon_i2c_hlc_wait(i2c);
+ /* Send core command */
+ ret = octeon_i2c_hlc_read_cmd(i2c, msgs[0], cmd);
if (ret)
goto err;
@@ -567,19 +593,8 @@ static int octeon_i2c_hlc_comp_write(struct octeon_i2c *i2c, struct i2c_msg *msg
/* A */
cmd |= (u64)(msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
- if (msgs[0].flags & I2C_M_TEN)
- cmd |= SW_TWSI_OP_10_IA;
- else
- cmd |= SW_TWSI_OP_7_IA;
-
- if (msgs[0].len == 2) {
- cmd |= SW_TWSI_EIA;
- ext |= (u64)msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
- set_ext = true;
- cmd |= (u64)msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
- } else {
- cmd |= (u64)msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
- }
+ /* Set parameters for extended message (if required) */
+ set_ext = octeon_i2c_hlc_ext(i2c, msgs[0], &cmd, &ext);
for (i = 0, j = msgs[1].len - 1; i < msgs[1].len && i < 4; i++, j--)
cmd |= (u64)msgs[1].buf[j] << (8 * i);
@@ -592,10 +607,7 @@ static int octeon_i2c_hlc_comp_write(struct octeon_i2c *i2c, struct i2c_msg *msg
if (set_ext)
octeon_i2c_writeq_flush(ext, i2c->twsi_base + OCTEON_REG_SW_TWSI_EXT(i2c));
- octeon_i2c_hlc_int_clear(i2c);
- octeon_i2c_writeq_flush(cmd, i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
-
- ret = octeon_i2c_hlc_wait(i2c);
+ ret = octeon_i2c_hlc_cmd_send(i2c, cmd);
if (ret)
goto err;
--
2.47.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v11 2/2] i2c: octeon: Add block-mode i2c operations
2025-01-20 2:33 [PATCH v11 0/2] i2c: octeon: Add block-mode r/w Aryan Srivastava
2025-01-20 2:33 ` [PATCH v11 1/2] i2c: octeon: refactor common i2c operations Aryan Srivastava
@ 2025-01-20 2:33 ` Aryan Srivastava
2025-02-13 22:19 ` [PATCH v11 0/2] i2c: octeon: Add block-mode r/w Andi Shyti
2025-02-18 22:04 ` Andi Shyti
3 siblings, 0 replies; 7+ messages in thread
From: Aryan Srivastava @ 2025-01-20 2:33 UTC (permalink / raw)
To: Andi Shyti, Markus Elfring
Cc: linux-i2c, linux-kernel, Aryan Srivastava, Robert Richter
Add functions to perform block read and write operations. This applies
for cases where the requested operation is for >8 bytes of data.
When not using the block mode transfer, the driver will attempt a series
of 8 byte i2c operations until it reaches the desired total. For
example, for a 40 byte request the driver will complete 5 separate
transactions. This results in large transactions taking a significant
amount of time to process.
Add block mode such that the driver can request larger transactions, up
to 1024 bytes per transfer.
Many aspects of the block mode transfer is common with the regular 8
byte operations. Use generic functions for parts of the message
construction and sending the message. The key difference for the block
mode is the usage of separate FIFO buffer to store data.
Write to this buffer in the case of a write (before command send).
Read from this buffer in the case of a read (after command send).
Data is written into this buffer by placing data into the MSB onwards.
This means the bottom 8 bits of the data will match the top 8 bits, and
so on and so forth.
Set specific bits in message for block mode, enable block mode transfers
from global i2c management registers, construct message, send message,
read or write from FIFO buffer as required.
The block-mode transactions result in a significant speed increase in
large i2c requests.
Signed-off-by: Aryan Srivastava <aryan.srivastava@alliedtelesis.co.nz>
---
drivers/i2c/busses/i2c-octeon-core.c | 155 ++++++++++++++++++++++-
drivers/i2c/busses/i2c-octeon-core.h | 13 +-
drivers/i2c/busses/i2c-thunderx-pcidrv.c | 3 +
3 files changed, 164 insertions(+), 7 deletions(-)
diff --git a/drivers/i2c/busses/i2c-octeon-core.c b/drivers/i2c/busses/i2c-octeon-core.c
index 3fbc828508ab..be98f919c6d9 100644
--- a/drivers/i2c/busses/i2c-octeon-core.c
+++ b/drivers/i2c/busses/i2c-octeon-core.c
@@ -135,6 +135,32 @@ static void octeon_i2c_hlc_disable(struct octeon_i2c *i2c)
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);
}
+static void octeon_i2c_block_enable(struct octeon_i2c *i2c)
+{
+ u64 mode;
+
+ if (i2c->block_enabled || !OCTEON_REG_BLOCK_CTL(i2c))
+ return;
+
+ i2c->block_enabled = true;
+ mode = __raw_readq(i2c->twsi_base + OCTEON_REG_MODE(i2c));
+ mode |= TWSX_MODE_BLOCK_MODE;
+ octeon_i2c_writeq_flush(mode, i2c->twsi_base + OCTEON_REG_MODE(i2c));
+}
+
+static void octeon_i2c_block_disable(struct octeon_i2c *i2c)
+{
+ u64 mode;
+
+ if (!i2c->block_enabled || !OCTEON_REG_BLOCK_CTL(i2c))
+ return;
+
+ i2c->block_enabled = false;
+ mode = __raw_readq(i2c->twsi_base + OCTEON_REG_MODE(i2c));
+ mode &= ~TWSX_MODE_BLOCK_MODE;
+ octeon_i2c_writeq_flush(mode, i2c->twsi_base + OCTEON_REG_MODE(i2c));
+}
+
/**
* octeon_i2c_hlc_wait - wait for an HLC operation to complete
* @i2c: The struct octeon_i2c
@@ -281,6 +307,7 @@ static int octeon_i2c_start(struct octeon_i2c *i2c)
u8 stat;
octeon_i2c_hlc_disable(i2c);
+ octeon_i2c_block_disable(i2c);
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB | TWSI_CTL_STA);
ret = octeon_i2c_wait(i2c);
@@ -619,6 +646,114 @@ static int octeon_i2c_hlc_comp_write(struct octeon_i2c *i2c, struct i2c_msg *msg
return ret;
}
+/**
+ * octeon_i2c_hlc_block_comp_read - high-level-controller composite block read
+ * @i2c: The struct octeon_i2c
+ * @msgs: msg[0] contains address, place read data into msg[1]
+ *
+ * i2c core command is constructed and written into the SW_TWSI register.
+ * The execution of the command will result in requested data being
+ * placed into a FIFO buffer, ready to be read.
+ * Used in the case where the i2c xfer is for greater than 8 bytes of read data.
+ *
+ * Returns 0 on success, otherwise a negative errno.
+ */
+static int octeon_i2c_hlc_block_comp_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+ int len, ret = 0;
+ u64 cmd = 0;
+
+ octeon_i2c_hlc_enable(i2c);
+ octeon_i2c_block_enable(i2c);
+
+ /* Write (size - 1) into block control register */
+ len = msgs[1].len - 1;
+ octeon_i2c_writeq_flush((u64)(len), i2c->twsi_base + OCTEON_REG_BLOCK_CTL(i2c));
+
+ /* Prepare core command */
+ cmd = SW_TWSI_V | SW_TWSI_R | SW_TWSI_SOVR;
+ cmd |= (u64)(msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
+
+ /* Send core command */
+ ret = octeon_i2c_hlc_read_cmd(i2c, msgs[0], cmd);
+ if (ret)
+ return ret;
+
+ cmd = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
+ if ((cmd & SW_TWSI_R) == 0)
+ return octeon_i2c_check_status(i2c, false);
+
+ /* read data in FIFO */
+ octeon_i2c_writeq_flush(TWSX_BLOCK_STS_RESET_PTR,
+ i2c->twsi_base + OCTEON_REG_BLOCK_STS(i2c));
+ for (int i = 0; i < len; i += 8) {
+ u64 rd = __raw_readq(i2c->twsi_base + OCTEON_REG_BLOCK_FIFO(i2c));
+ /* Place data into msg buf from FIFO, MSB onwards */
+ for (int j = 7; j >= 0; j--)
+ msgs[1].buf[i + (7 - j)] = (rd >> (8 * j)) & 0xff;
+ }
+
+ octeon_i2c_block_disable(i2c);
+ return ret;
+}
+
+/**
+ * octeon_i2c_hlc_block_comp_write - high-level-controller composite block write
+ * @i2c: The struct octeon_i2c
+ * @msgs: msg[0] contains address, msg[1] contains data to be written
+ *
+ * i2c core command is constructed and write data is written into the FIFO buffer.
+ * The execution of the command will result in HW write, using the data in FIFO.
+ * Used in the case where the i2c xfer is for greater than 8 bytes of write data.
+ *
+ * Returns 0 on success, otherwise a negative errno.
+ */
+static int octeon_i2c_hlc_block_comp_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
+{
+ bool set_ext = false;
+ int len, ret = 0;
+ u64 cmd, ext = 0;
+
+ octeon_i2c_hlc_enable(i2c);
+ octeon_i2c_block_enable(i2c);
+
+ /* Write (size - 1) into block control register */
+ len = msgs[1].len - 1;
+ octeon_i2c_writeq_flush((u64)(len), i2c->twsi_base + OCTEON_REG_BLOCK_CTL(i2c));
+
+ /* Prepare core command */
+ cmd = SW_TWSI_V | SW_TWSI_SOVR;
+ cmd |= (u64)(msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
+
+ /* Set parameters for extended message (if required) */
+ set_ext = octeon_i2c_hlc_ext(i2c, msgs[0], &cmd, &ext);
+
+ /* Write msg into FIFO buffer */
+ octeon_i2c_writeq_flush(TWSX_BLOCK_STS_RESET_PTR,
+ i2c->twsi_base + OCTEON_REG_BLOCK_STS(i2c));
+ for (int i = 0; i < len; i += 8) {
+ u64 buf = 0;
+ /* Place data from msg buf into FIFO, MSB onwards */
+ for (int j = 7; j >= 0; j--)
+ buf |= (msgs[1].buf[i + (7 - j)] << (8 * j));
+ octeon_i2c_writeq_flush(buf, i2c->twsi_base + OCTEON_REG_BLOCK_FIFO(i2c));
+ }
+ if (set_ext)
+ octeon_i2c_writeq_flush(ext, i2c->twsi_base + OCTEON_REG_SW_TWSI_EXT(i2c));
+
+ /* Send command to core (send data in FIFO) */
+ ret = octeon_i2c_hlc_cmd_send(i2c, cmd);
+ if (ret)
+ return ret;
+
+ cmd = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
+ if ((cmd & SW_TWSI_R) == 0)
+ return octeon_i2c_check_status(i2c, false);
+
+ octeon_i2c_block_disable(i2c);
+ return ret;
+}
+
/**
* octeon_i2c_xfer - The driver's xfer function
* @adap: Pointer to the i2c_adapter structure
@@ -645,13 +780,21 @@ int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
if ((msgs[0].flags & I2C_M_RD) == 0 &&
(msgs[1].flags & I2C_M_RECV_LEN) == 0 &&
msgs[0].len > 0 && msgs[0].len <= 2 &&
- msgs[1].len > 0 && msgs[1].len <= 8 &&
+ msgs[1].len > 0 &&
msgs[0].addr == msgs[1].addr) {
- if (msgs[1].flags & I2C_M_RD)
- ret = octeon_i2c_hlc_comp_read(i2c, msgs);
- else
- ret = octeon_i2c_hlc_comp_write(i2c, msgs);
- goto out;
+ if (msgs[1].len <= 8) {
+ if (msgs[1].flags & I2C_M_RD)
+ ret = octeon_i2c_hlc_comp_read(i2c, msgs);
+ else
+ ret = octeon_i2c_hlc_comp_write(i2c, msgs);
+ goto out;
+ } else if (msgs[1].len <= 1024 && OCTEON_REG_BLOCK_CTL(i2c)) {
+ if (msgs[1].flags & I2C_M_RD)
+ ret = octeon_i2c_hlc_block_comp_read(i2c, msgs);
+ else
+ ret = octeon_i2c_hlc_block_comp_write(i2c, msgs);
+ goto out;
+ }
}
}
}
diff --git a/drivers/i2c/busses/i2c-octeon-core.h b/drivers/i2c/busses/i2c-octeon-core.h
index b265e21189a1..fecaf7388182 100644
--- a/drivers/i2c/busses/i2c-octeon-core.h
+++ b/drivers/i2c/busses/i2c-octeon-core.h
@@ -96,18 +96,28 @@ struct octeon_i2c_reg_offset {
unsigned int twsi_int;
unsigned int sw_twsi_ext;
unsigned int mode;
+ unsigned int block_ctl;
+ unsigned int block_sts;
+ unsigned int block_fifo;
};
#define OCTEON_REG_SW_TWSI(x) ((x)->roff.sw_twsi)
#define OCTEON_REG_TWSI_INT(x) ((x)->roff.twsi_int)
#define OCTEON_REG_SW_TWSI_EXT(x) ((x)->roff.sw_twsi_ext)
#define OCTEON_REG_MODE(x) ((x)->roff.mode)
+#define OCTEON_REG_BLOCK_CTL(x) (x->roff.block_ctl)
+#define OCTEON_REG_BLOCK_STS(x) (x->roff.block_sts)
+#define OCTEON_REG_BLOCK_FIFO(x) (x->roff.block_fifo)
-/* Set REFCLK_SRC and HS_MODE in TWSX_MODE register */
+/* TWSX_MODE register */
#define TWSX_MODE_REFCLK_SRC BIT(4)
+#define TWSX_MODE_BLOCK_MODE BIT(2)
#define TWSX_MODE_HS_MODE BIT(0)
#define TWSX_MODE_HS_MASK (TWSX_MODE_REFCLK_SRC | TWSX_MODE_HS_MODE)
+/* TWSX_BLOCK_STS register */
+#define TWSX_BLOCK_STS_RESET_PTR BIT(0)
+
/* Set BUS_MON_RST to reset bus monitor */
#define BUS_MON_RST_MASK BIT(3)
@@ -123,6 +133,7 @@ struct octeon_i2c {
void __iomem *twsi_base;
struct device *dev;
bool hlc_enabled;
+ bool block_enabled;
bool broken_irq_mode;
bool broken_irq_check;
void (*int_enable)(struct octeon_i2c *);
diff --git a/drivers/i2c/busses/i2c-thunderx-pcidrv.c b/drivers/i2c/busses/i2c-thunderx-pcidrv.c
index 143d012fa43e..0dc08cd97e8a 100644
--- a/drivers/i2c/busses/i2c-thunderx-pcidrv.c
+++ b/drivers/i2c/busses/i2c-thunderx-pcidrv.c
@@ -168,6 +168,9 @@ static int thunder_i2c_probe_pci(struct pci_dev *pdev,
i2c->roff.twsi_int = 0x1010;
i2c->roff.sw_twsi_ext = 0x1018;
i2c->roff.mode = 0x1038;
+ i2c->roff.block_ctl = 0x1048;
+ i2c->roff.block_sts = 0x1050;
+ i2c->roff.block_fifo = 0x1058;
i2c->dev = dev;
pci_set_drvdata(pdev, i2c);
--
2.47.1
^ permalink raw reply related [flat|nested] 7+ messages in thread