[PATCH net-next v8 2/9] i2c: designware: Add driver support for Wangxun 10Gb NIC

Jiawen Wu
2023-05-15T06:34:27Z

Wangxun 10Gb ethernet chip is connected to Designware I2C, to communicate
with SFP.

Introduce the property "snps,i2c-platform" to match device data for Wangxun
in software node case. Since IO resource was mapped on the ethernet driver,
add a model quirk to get regmap from parent device.

The exists IP limitations are dealt as workarounds:
- IP does not support interrupt mode, it works on polling mode.
- Additionally set FIFO depth address the chip issue.

Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
Reviewed-by: Piotr Raczynski <piotr.raczynski@intel.com>
---
drivers/i2c/busses/i2c-designware-common.c | 8 ++
drivers/i2c/busses/i2c-designware-core.h | 4 +
drivers/i2c/busses/i2c-designware-master.c | 89 +++++++++++++++++++--
drivers/i2c/busses/i2c-designware-platdrv.c | 15 ++++
4 files changed, 111 insertions(+), 5 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c
index 0dc6b1ce663f..cdd8c67d9129 100644
--- a/drivers/i2c/busses/i2c-designware-common.c
+++ b/drivers/i2c/busses/i2c-designware-common.c
@@ -575,6 +575,14 @@ int i2c_dw_set_fifo_size(struct dw_i2c_dev *dev)
unsigned int param;
int ret;

+ /* DW_IC_COMP_PARAM_1 not implement for IP issue */
+ if ((dev->flags & MODEL_MASK) == MODEL_WANGXUN_SP) {
+ dev->tx_fifo_depth = TXGBE_TX_FIFO_DEPTH;
+ dev->rx_fifo_depth = TXGBE_RX_FIFO_DEPTH;
+
+ return 0;
+ }
+
/*
* Try to detect the FIFO depth if not set by interface driver,
* the depth could be from 2 to 256 from HW spec.
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index c5d87aae39c6..782532c20bd1 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -303,6 +303,7 @@ struct dw_i2c_dev {
#define MODEL_MSCC_OCELOT BIT(8)
#define MODEL_BAIKAL_BT1 BIT(9)
#define MODEL_AMD_NAVI_GPU BIT(10)
+#define MODEL_WANGXUN_SP BIT(11)
#define MODEL_MASK GENMASK(11, 8)

/*
@@ -312,6 +313,9 @@ struct dw_i2c_dev {
#define AMD_UCSI_INTR_REG 0x474
#define AMD_UCSI_INTR_EN 0xd

+#define TXGBE_TX_FIFO_DEPTH 4
+#define TXGBE_RX_FIFO_DEPTH 0
+
struct i2c_dw_semaphore_callbacks {
int (*probe)(struct dw_i2c_dev *dev);
void (*remove)(struct dw_i2c_dev *dev);
diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index 55ea91a63382..3bfd7a2232db 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -354,6 +354,68 @@ static int amd_i2c_dw_xfer_quirk(struct i2c_adapter *adap, struct i2c_msg *msgs,
return 0;
}

+static int i2c_dw_poll_tx_empty(struct dw_i2c_dev *dev)
+{
+ u32 val;
+
+ return regmap_read_poll_timeout(dev->map, DW_IC_RAW_INTR_STAT, val,
+ val & DW_IC_INTR_TX_EMPTY,
+ 100, 1000);
+}
+
+static int i2c_dw_poll_rx_full(struct dw_i2c_dev *dev)
+{
+ u32 val;
+
+ return regmap_read_poll_timeout(dev->map, DW_IC_RAW_INTR_STAT, val,
+ val & DW_IC_INTR_RX_FULL,
+ 100, 1000);
+}
+
+static int txgbe_i2c_dw_xfer_quirk(struct i2c_adapter *adap, struct i2c_msg *msgs,
+ int num_msgs)
+{
+ struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
+ int msg_idx, buf_len, data_idx, ret;
+ unsigned int val, stop = 0;
+ u8 *buf;
+
+ dev->msgs = msgs;
+ dev->msgs_num = num_msgs;
+ i2c_dw_xfer_init(dev);
+ regmap_write(dev->map, DW_IC_INTR_MASK, 0);
+
+ for (msg_idx = 0; msg_idx < num_msgs; msg_idx++) {
+ buf = msgs[msg_idx].buf;
+ buf_len = msgs[msg_idx].len;
+
+ for (data_idx = 0; data_idx < buf_len; data_idx++) {
+ if (msg_idx == num_msgs - 1 && data_idx == buf_len - 1)
+ stop |= BIT(9);
+
+ if (msgs[msg_idx].flags & I2C_M_RD) {
+ regmap_write(dev->map, DW_IC_DATA_CMD, 0x100 | stop);
+
+ ret = i2c_dw_poll_rx_full(dev);
+ if (ret)
+ return ret;
+
+ regmap_read(dev->map, DW_IC_DATA_CMD, &val);
+ buf[data_idx] = val;
+ } else {
+ ret = i2c_dw_poll_tx_empty(dev);
+ if (ret)
+ return ret;
+
+ regmap_write(dev->map, DW_IC_DATA_CMD,
+ buf[data_idx] | stop);
+ }
+ }
+ }
+
+ return num_msgs;
+}
+
/*
* Initiate (and continue) low level master read/write transaction.
* This function is only called from i2c_dw_isr, and pumping i2c_msg
@@ -559,13 +621,19 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
pm_runtime_get_sync(dev->dev);

/*
- * Initiate I2C message transfer when AMD NAVI GPU card is enabled,
+ * Initiate I2C message transfer when polling mode is enabled,
* As it is polling based transfer mechanism, which does not support
* interrupt based functionalities of existing DesignWare driver.
*/
- if ((dev->flags & MODEL_MASK) == MODEL_AMD_NAVI_GPU) {
+ switch (dev->flags & MODEL_MASK) {
+ case MODEL_AMD_NAVI_GPU:
ret = amd_i2c_dw_xfer_quirk(adap, msgs, num);
goto done_nolock;
+ case MODEL_WANGXUN_SP:
+ ret = txgbe_i2c_dw_xfer_quirk(adap, msgs, num);
+ goto done_nolock;
+ default:
+ break;
}

reinit_completion(&dev->cmd_complete);
@@ -848,7 +916,7 @@ static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev)
return 0;
}

-static int amd_i2c_adap_quirk(struct dw_i2c_dev *dev)
+static int i2c_dw_poll_adap_quirk(struct dw_i2c_dev *dev)
{
struct i2c_adapter *adap = &dev->adapter;
int ret;
@@ -862,6 +930,17 @@ static int amd_i2c_adap_quirk(struct dw_i2c_dev *dev)
return ret;
}

+static bool i2c_dw_is_model_poll(struct dw_i2c_dev *dev)
+{
+ switch (dev->flags & MODEL_MASK) {
+ case MODEL_AMD_NAVI_GPU:
+ case MODEL_WANGXUN_SP:
+ return true;
+ default:
+ return false;
+ }
+}
+
int i2c_dw_probe_master(struct dw_i2c_dev *dev)
{
struct i2c_adapter *adap = &dev->adapter;
@@ -917,8 +996,8 @@ int i2c_dw_probe_master(struct dw_i2c_dev *dev)
adap->dev.parent = dev->dev;
i2c_set_adapdata(adap, dev);

- if ((dev->flags & MODEL_MASK) == MODEL_AMD_NAVI_GPU)
- return amd_i2c_adap_quirk(dev);
+ if (i2c_dw_is_model_poll(dev))
+ return i2c_dw_poll_adap_quirk(dev);

if (dev->flags & ACCESS_NO_IRQ_SUSPEND) {
irq_flags = IRQF_NO_SUSPEND;
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 89ad88c54754..1bf50150386d 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -168,6 +168,15 @@ static inline int dw_i2c_of_configure(struct platform_device *pdev)
}
#endif

+static int txgbe_i2c_request_regs(struct dw_i2c_dev *dev)
+{
+ dev->map = dev_get_regmap(dev->dev->parent, NULL);
+ if (!dev->map)
+ return -ENODEV;
+
+ return 0;
+}
+
static void dw_i2c_plat_pm_cleanup(struct dw_i2c_dev *dev)
{
pm_runtime_disable(dev->dev);
@@ -185,6 +194,9 @@ static int dw_i2c_plat_request_regs(struct dw_i2c_dev *dev)
case MODEL_BAIKAL_BT1:
ret = bt1_i2c_request_regs(dev);
break;
+ case MODEL_WANGXUN_SP:
+ ret = txgbe_i2c_request_regs(dev);
+ break;
default:
dev->base = devm_platform_ioremap_resource(pdev, 0);
ret = PTR_ERR_OR_ZERO(dev->base);
@@ -277,6 +289,9 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
return -ENOMEM;

dev->flags = (uintptr_t)device_get_match_data(&pdev->dev);
+ if (device_property_present(&pdev->dev, "snps,i2c-platform"))
+ dev->flags |= MODEL_WANGXUN_SP;
+
dev->dev = &pdev->dev;
dev->irq = irq;
platform_set_drvdata(pdev, dev);
--
2.27.0