[PATCH net-next v4 04/12] net: ethernet: oa_tc6: implement software reset

Parthiban Veerasooran
2024-04-18T12:57:40Z

Reset complete bit is set when the MAC-PHY reset completes and ready for
configuration. Additionally reset complete bit in the STS0 register has
to be written by one upon reset complete to clear the interrupt.

Signed-off-by: Parthiban Veerasooran <Parthiban.Veerasooran@microchip.com>
---
drivers/net/ethernet/oa_tc6.c | 53 +++++++++++++++++++++++++++++++++++
1 file changed, 53 insertions(+)

diff --git a/drivers/net/ethernet/oa_tc6.c b/drivers/net/ethernet/oa_tc6.c
index f563329912e2..4b0f63c02c35 100644
--- a/drivers/net/ethernet/oa_tc6.c
+++ b/drivers/net/ethernet/oa_tc6.c
@@ -6,8 +6,18 @@
*/

#include <linux/bitfield.h>
+#include <linux/iopoll.h>
#include <linux/oa_tc6.h>

+/* OPEN Alliance TC6 registers */
+/* Reset Control and Status Register */
+#define OA_TC6_REG_RESET 0x0003
+#define RESET_SWRESET BIT(0) /* Software Reset */
+
+/* Status Register #0 */
+#define OA_TC6_REG_STATUS0 0x0008
+#define STATUS0_RESETC BIT(6) /* Reset Complete */
+
/* Control command header */
#define OA_TC6_CTRL_HEADER_DATA_NOT_CTRL BIT(31)
#define OA_TC6_CTRL_HEADER_WRITE_NOT_READ BIT(29)
@@ -24,6 +34,8 @@
(OA_TC6_CTRL_MAX_REGISTERS *\
OA_TC6_CTRL_REG_VALUE_SIZE) +\
OA_TC6_CTRL_IGNORED_SIZE)
+#define STATUS0_RESETC_POLL_DELAY 1000
+#define STATUS0_RESETC_POLL_TIMEOUT 1000000

/* Internal structure for MAC-PHY drivers */
struct oa_tc6 {
@@ -279,6 +291,39 @@ int oa_tc6_write_register(struct oa_tc6 *tc6, u32 address, u32 value)
}
EXPORT_SYMBOL_GPL(oa_tc6_write_register);

+static int oa_tc6_read_status0(struct oa_tc6 *tc6)
+{
+ u32 regval;
+ int ret;
+
+ ret = oa_tc6_read_register(tc6, OA_TC6_REG_STATUS0, &regval);
+ if (ret)
+ return 0;
+
+ return regval;
+}
+
+static int oa_tc6_sw_reset_macphy(struct oa_tc6 *tc6)
+{
+ u32 regval = RESET_SWRESET;
+ int ret;
+
+ ret = oa_tc6_write_register(tc6, OA_TC6_REG_RESET, regval);
+ if (ret)
+ return ret;
+
+ /* Poll for soft reset complete for every 1ms until 1s timeout */
+ ret = readx_poll_timeout(oa_tc6_read_status0, tc6, regval,
+ regval & STATUS0_RESETC,
+ STATUS0_RESETC_POLL_DELAY,
+ STATUS0_RESETC_POLL_TIMEOUT);
+ if (ret)
+ return -ENODEV;
+
+ /* Clear the reset complete status */
+ return oa_tc6_write_register(tc6, OA_TC6_REG_STATUS0, regval);
+}
+
/**
* oa_tc6_init - allocates and initializes oa_tc6 structure.
* @spi: device with which data will be exchanged.
@@ -289,6 +334,7 @@ EXPORT_SYMBOL_GPL(oa_tc6_write_register);
struct oa_tc6 *oa_tc6_init(struct spi_device *spi)
{
struct oa_tc6 *tc6;
+ int ret;

tc6 = devm_kzalloc(&spi->dev, sizeof(*tc6), GFP_KERNEL);
if (!tc6)
@@ -311,6 +357,13 @@ struct oa_tc6 *oa_tc6_init(struct spi_device *spi)
if (!tc6->spi_ctrl_rx_buf)
return NULL;

+ ret = oa_tc6_sw_reset_macphy(tc6);
+ if (ret) {
+ dev_err(&tc6->spi->dev,
+ "MAC-PHY software reset failed: %d\n", ret);
+ return NULL;
+ }
+
return tc6;
}
EXPORT_SYMBOL_GPL(oa_tc6_init);
--
2.34.1