mtd: nand: sunxi: add reset line support

The NAND controller on some sun8i chips needs its reset line to be
deasserted before they can enter working state.

Signed-off-by: Icenowy Zheng <icenowy@aosc.xyz>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

1 files changed, 23 insertions, 2 deletions

diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
index f582fe41d61d..d2b7457d447f 100644
--- a/drivers/mtd/nand/sunxi_nand.c
+++ b/drivers/mtd/nand/sunxi_nand.c
@@ -39,6 +39,7 @@
 #include <linux/gpio.h>
 #include <linux/interrupt.h>
 #include <linux/iopoll.h>
+#include <linux/reset.h>
 
 #define NFC_REG_CTL             0x0000
 #define NFC_REG_ST              0x0004
@@ -270,6 +271,7 @@ struct sunxi_nfc {
         void __iomem *regs;
         struct clk *ahb_clk;
         struct clk *mod_clk;
+        struct reset_control *reset;
         unsigned long assigned_cs;
         unsigned long clk_rate;
         struct list_head chips;
@@ -2209,15 +2211,27 @@ static int sunxi_nfc_probe(struct platform_device *pdev)
         if (ret)
                 goto out_ahb_clk_unprepare;
 
+        nfc->reset = devm_reset_control_get_optional(dev, "ahb");
+        if (!IS_ERR(nfc->reset)) {
+                ret = reset_control_deassert(nfc->reset);
+                if (ret) {
+                        dev_err(dev, "reset err %d\n", ret);
+                        goto out_mod_clk_unprepare;
+                }
+        } else if (PTR_ERR(nfc->reset) != -ENOENT) {
+                ret = PTR_ERR(nfc->reset);
+                goto out_mod_clk_unprepare;
+        }
+
         ret = sunxi_nfc_rst(nfc);
         if (ret)
-                goto out_mod_clk_unprepare;
+                goto out_ahb_reset_reassert;
 
         writel(0, nfc->regs + NFC_REG_INT);
         ret = devm_request_irq(dev, irq, sunxi_nfc_interrupt,
                                0, "sunxi-nand", nfc);
         if (ret)
-                goto out_mod_clk_unprepare;
+                goto out_ahb_reset_reassert;
 
         nfc->dmac = dma_request_slave_channel(dev, "rxtx");
         if (nfc->dmac) {
@@ -2247,6 +2261,9 @@ static int sunxi_nfc_probe(struct platform_device *pdev)
 out_release_dmac:
         if (nfc->dmac)
                 dma_release_channel(nfc->dmac);
+out_ahb_reset_reassert:
+        if (!IS_ERR(nfc->reset))
+                reset_control_assert(nfc->reset);
 out_mod_clk_unprepare:
         clk_disable_unprepare(nfc->mod_clk);
 out_ahb_clk_unprepare:
@@ -2260,6 +2277,10 @@ static int sunxi_nfc_remove(struct platform_device *pdev)
         struct sunxi_nfc *nfc = platform_get_drvdata(pdev);
 
         sunxi_nand_chips_cleanup(nfc);
+
+        if (!IS_ERR(nfc->reset))
+                reset_control_assert(nfc->reset);
+
         if (nfc->dmac)
                 dma_release_channel(nfc->dmac);
         clk_disable_unprepare(nfc->mod_clk);