[PATCH 1/2] net: allwinner: reset control support

[Evgeny Boger]

R40 (aka V40/A40i/T3) and A10/A20 share the same EMAC IP.
However, on R40 the EMAC is gated by default.

Signed-off-by: Evgeny Boger <bo...@wirenboard.com>
---
 drivers/net/ethernet/allwinner/sun4i-emac.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/allwinner/sun4i-emac.c 
b/drivers/net/ethernet/allwinner/sun4i-emac.c
index 5ed80d9a6b9f..c0ae06dd922c 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"
@@ -85,6 +86,7 @@ struct emac_board_info {
        unsigned int            link;
        unsigned int            speed;
        unsigned int            duplex;
+       struct reset_control *reset;
 
        phy_interface_t         phy_interface;
 };
@@ -791,6 +793,7 @@ static int emac_probe(struct platform_device *pdev)
        struct net_device *ndev;
        int ret = 0;
        const char *mac_addr;
+       struct reset_control *reset;
 
        ndev = alloc_etherdev(sizeof(struct emac_board_info));
        if (!ndev) {
@@ -852,6 +855,19 @@ static int emac_probe(struct platform_device *pdev)
                goto out_release_sram;
        }
 
+       reset = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
+       if (IS_ERR(reset)) {
+               dev_err(&pdev->dev, "unable to request reset\n");
+               ret = -ENODEV;
+               goto out_release_sram;
+       }
+       db->reset = reset;
+       ret = reset_control_deassert(db->reset);
+       if (ret) {
+               dev_err(&pdev->dev, "could not deassert EMAC reset\n");
+               goto out_release_sram;
+       }
+
        /* Read MAC-address from DT */
        mac_addr = of_get_mac_address(np);
        if (!IS_ERR(mac_addr))
@@ -881,7 +897,7 @@ static int emac_probe(struct platform_device *pdev)
        if (ret) {
                dev_err(&pdev->dev, "Registering netdev failed!\n");
                ret = -ENODEV;
-               goto out_release_sram;
+               goto out_assert_reset;
        }
 
        dev_info(&pdev->dev, "%s: at %p, IRQ %d MAC: %pM\n",
@@ -889,6 +905,8 @@ static int emac_probe(struct platform_device *pdev)
 
        return 0;
 
+out_assert_reset:
+       reset_control_assert(db->reset);
 out_release_sram:
        sunxi_sram_release(&pdev->dev);
 out_clk_disable_unprepare:
@@ -913,6 +931,7 @@ 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);
-- 
2.17.1