[PATCH v4 1/3] net: allwinner: reset control support

Evgeny Boger
2022-01-11T16:07:54Z

R40 (aka V40/A40i/T3) and A10/A20 share the same EMAC IP.
However, on R40 the EMAC reset needs to be deasserted.

Signed-off-by: Evgeny Boger <boger@wirenboard.com>
---
drivers/net/ethernet/allwinner/sun4i-emac.c | 64 +++++++++++++++++++--
1 file changed, 59 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/allwinner/sun4i-emac.c b/drivers/net/ethernet/allwinner/sun4i-emac.c
index 800ee022388f..368597f0ff76 100644
--- a/drivers/net/ethernet/allwinner/sun4i-emac.c
+++ b/drivers/net/ethernet/allwinner/sun4i-emac.c
@@ -28,6 +28,7 @@
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/phy.h>
+#include <linux/reset.h>
#include <linux/soc/sunxi/sunxi_sram.h>

#include "sun4i-emac.h"
@@ -68,6 +69,15 @@ MODULE_PARM_DESC(watchdog, "transmit timeout in milliseconds");
* devices, EMACA and EMACB.
*/

+/**
+ * struct emac_quirks - Differences between SoC variants.
+ *
+ * @has_reset: SoC needs reset deasserted.
+ */
+struct emac_quirks {
+ bool has_reset;
+};
+
struct emac_board_info {
struct clk *clk;
struct device *dev;
@@ -85,6 +95,7 @@ struct emac_board_info {
unsigned int link;
unsigned int speed;
unsigned int duplex;
+ struct reset_control *reset;

phy_interface_t phy_interface;
};
@@ -790,6 +801,7 @@ static int emac_probe(struct platform_device *pdev)
struct emac_board_info *db;
struct net_device *ndev;
int ret = 0;
+ const struct emac_quirks *quirks;

ndev = alloc_etherdev(sizeof(struct emac_board_info));
if (!ndev) {
@@ -808,6 +820,13 @@ static int emac_probe(struct platform_device *pdev)

spin_lock_init(&db->lock);

+ quirks = of_device_get_match_data(&pdev->dev);
+ if (!quirks) {
+ dev_err(&pdev->dev, "Failed to determine the quirks to use\n");
+ ret = -ENODEV;
+ goto out;
+ }
+
db->membase = of_iomap(np, 0);
if (!db->membase) {
dev_err(&pdev->dev, "failed to remap registers\n");
@@ -824,16 +843,31 @@ static int emac_probe(struct platform_device *pdev)
goto out_iounmap;
}

+ if (quirks->has_reset) {
+ db->reset = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+ if (IS_ERR(db->reset)) {
+ dev_err(&pdev->dev, "unable to request reset\n");
+ ret = PTR_ERR(db->reset);
+ goto out_dispose_mapping;
+ }
+
+ ret = reset_control_deassert(db->reset);
+ if (ret) {
+ dev_err(&pdev->dev, "could not deassert EMAC reset\n");
+ goto out_dispose_mapping;
+ }
+ }
+
db->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(db->clk)) {
ret = PTR_ERR(db->clk);
- goto out_dispose_mapping;
+ goto out_assert_reset;
}

ret = clk_prepare_enable(db->clk);
if (ret) {
dev_err(&pdev->dev, "Error couldn't enable clock (%d)\n", ret);
- goto out_dispose_mapping;
+ goto out_assert_reset;
}

ret = sunxi_sram_claim(&pdev->dev);
@@ -889,6 +923,8 @@ static int emac_probe(struct platform_device *pdev)
sunxi_sram_release(&pdev->dev);
out_clk_disable_unprepare:
clk_disable_unprepare(db->clk);
+out_assert_reset:
+ reset_control_assert(db->reset);
out_dispose_mapping:
irq_dispose_mapping(ndev->irq);
out_iounmap:
@@ -909,6 +945,7 @@ static int emac_remove(struct platform_device *pdev)
unregister_netdev(ndev);
sunxi_sram_release(&pdev->dev);
clk_disable_unprepare(db->clk);
+ reset_control_assert(db->reset);
irq_dispose_mapping(ndev->irq);
iounmap(db->membase);
free_netdev(ndev);
@@ -940,11 +977,28 @@ static int emac_resume(struct platform_device *dev)
return 0;
}

-static const struct of_device_id emac_of_match[] = {
- {.compatible = "allwinner,sun4i-a10-emac",},
+static const struct emac_quirks sun4i_a10_emac_quirks = {
+ .has_reset = false,
+};
+
+static const struct emac_quirks sun8i_r40_emac_quirks = {
+ .has_reset = true,
+};

+static const struct of_device_id emac_of_match[] = {
+ {
+ .compatible = "allwinner,sun4i-a10-emac",
+ .data = &sun4i_a10_emac_quirks
+ },
+ {
+ .compatible = "allwinner,sun8i-r40-emac",
+ .data = &sun8i_r40_emac_quirks
+ },
/* Deprecated */
- {.compatible = "allwinner,sun4i-emac",},
+ {
+ .compatible = "allwinner,sun4i-emac",
+ .data = &sun4i_a10_emac_quirks
+ },
{},