ar71xx: rb91x-nand: rewrite to use GPIO API
[openwrt/staging/stintel.git] / target / linux / ar71xx / files / drivers / mtd / nand / rb91x_nand.c
index 99828cb34c36f3bc504f11078a0cbbbf5a8ead4c..f0aa3c3e79f440905393146c16f492a9a6bd4ff2 100644 (file)
@@ -1,7 +1,7 @@
 /*
  *  NAND flash driver for the MikroTik RouterBOARD 91x series
  *
- *  Copyright (C) 2013 Gabor Juhos <juhosg@openwrt.org>
+ *  Copyright (C) 2013-2014 Gabor Juhos <juhosg@openwrt.org>
  *
  *  This program is free software; you can redistribute it and/or modify it
  *  under the terms of the GNU General Public License version 2 as published
 #include <linux/platform_device.h>
 #include <linux/io.h>
 #include <linux/slab.h>
+#include <linux/gpio.h>
+#include <linux/platform_data/rb91x_nand.h>
 
 #include <asm/mach-ath79/ar71xx_regs.h>
 #include <asm/mach-ath79/ath79.h>
 
-#define DRV_NAME       "rb91x-nand"
 #define DRV_DESC       "NAND flash driver for the RouterBOARD 91x series"
 
-#define RB91X_NAND_NRE_ENABLE  BIT(3)
-#define RB91X_NAND_RDY         BIT(4)
-#define RB91X_LATCH_ENABLE     BIT(11)
 #define RB91X_NAND_NRWE                BIT(12)
-#define RB91X_NAND_NCE         BIT(13)
-#define RB91X_NAND_CLE         BIT(14)
-#define RB91X_NAND_ALE         BIT(15)
 
 #define RB91X_NAND_DATA_BITS   (BIT(0) | BIT(1) | BIT(2) | BIT(3) | BIT(4) |\
                                 BIT(13) | BIT(14) | BIT(15))
 
 #define RB91X_NAND_INPUT_BITS  (RB91X_NAND_DATA_BITS | RB91X_NAND_RDY)
-#define RB91X_NAND_OUTPUT_BITS \
-       (RB91X_NAND_DATA_BITS | RB91X_NAND_NRWE)
+#define RB91X_NAND_OUTPUT_BITS (RB91X_NAND_DATA_BITS | RB91X_NAND_NRWE)
 
 #define RB91X_NAND_LOW_DATA_MASK       0x1f
 #define RB91X_NAND_HIGH_DATA_MASK      0xe0
 #define RB91X_NAND_HIGH_DATA_SHIFT     8
 
 struct rb91x_nand_info {
-       struct nand_chip        chip;
-       struct mtd_info         mtd;
+       struct nand_chip chip;
+       struct mtd_info mtd;
+       struct device *dev;
+
+       int gpio_nce;
+       int gpio_ale;
+       int gpio_cle;
+       int gpio_rdy;
+       int gpio_read;
+       int gpio_nrw;
+       int gpio_nle;
 };
 
 static inline struct rb91x_nand_info *mtd_to_rbinfo(struct mtd_info *mtd)
@@ -81,53 +84,9 @@ static struct mtd_partition rb91x_nand_partitions[] = {
        },
 };
 
-static void rb91x_change_gpo(u32 clear, u32 set)
-{
-       void __iomem *base = ath79_gpio_base;
-       static unsigned on = 0xE002800;
-       static unsigned off = 0x0000C008;
-       static unsigned oe = 0;
-       static DEFINE_SPINLOCK(lock);
-       unsigned long flags;
-
-       spin_lock_irqsave(&lock, flags);
-
-       on = (on | set) & ~clear;
-       off = (off | clear) & ~set;
-
-       if (!oe)
-               oe = __raw_readl(base + AR71XX_GPIO_REG_OE);
-
-       if (on & RB91X_LATCH_ENABLE) {
-               u32 t;
-
-               t = oe & __raw_readl(base + AR71XX_GPIO_REG_OE);
-               t &= ~(on | off);
-               __raw_writel(t, base + AR71XX_GPIO_REG_OE);
-               __raw_writel(off, base + AR71XX_GPIO_REG_CLEAR);
-               __raw_writel(on, base + AR71XX_GPIO_REG_SET);
-       } else if (clear & RB91X_LATCH_ENABLE) {
-               oe = __raw_readl(base + AR71XX_GPIO_REG_OE);
-               __raw_writel(RB91X_LATCH_ENABLE,
-                            base + AR71XX_GPIO_REG_CLEAR);
-               /* flush write */
-               __raw_readl(base + AR71XX_GPIO_REG_CLEAR);
-       }
-
-       spin_unlock_irqrestore(&lock, flags);
-}
-
-static inline void rb91x_latch_enable(void)
-{
-       rb91x_change_gpo(RB91X_LATCH_ENABLE, 0);
-}
-
-static inline void rb91x_latch_disable(void)
-{
-       rb91x_change_gpo(0, RB91X_LATCH_ENABLE);
-}
-
-static void rb91x_nand_write(const u8 *buf, unsigned len)
+static void rb91x_nand_write(struct rb91x_nand_info *rbni,
+                            const u8 *buf,
+                            unsigned len)
 {
        void __iomem *base = ath79_gpio_base;
        u32 oe_reg;
@@ -135,7 +94,8 @@ static void rb91x_nand_write(const u8 *buf, unsigned len)
        u32 out;
        unsigned i;
 
-       rb91x_latch_enable();
+       /* enable the latch */
+       gpio_set_value_cansleep(rbni->gpio_nle, 0);
 
        oe_reg = __raw_readl(base + AR71XX_GPIO_REG_OE);
        out_reg = __raw_readl(base + AR71XX_GPIO_REG_OUT);
@@ -162,30 +122,32 @@ static void rb91x_nand_write(const u8 *buf, unsigned len)
        }
 
        /* restore  registers */
-       __raw_writel(oe_reg, base + AR71XX_GPIO_REG_OE);
        __raw_writel(out_reg, base + AR71XX_GPIO_REG_OUT);
+       __raw_writel(oe_reg, base + AR71XX_GPIO_REG_OE);
        /* flush write */
        __raw_readl(base + AR71XX_GPIO_REG_OUT);
 
-       rb91x_latch_disable();
+       /* disable the latch */
+       gpio_set_value_cansleep(rbni->gpio_nle, 1);
 }
 
-static void rb91x_nand_read(u8 *read_buf, unsigned len)
+static void rb91x_nand_read(struct rb91x_nand_info *rbni,
+                           u8 *read_buf,
+                           unsigned len)
 {
        void __iomem *base = ath79_gpio_base;
        u32 oe_reg;
        u32 out_reg;
        unsigned i;
 
-       /* save registers */
-       oe_reg = __raw_readl(base + AR71XX_GPIO_REG_OE);
-
-       /* select nRE mode */
-       rb91x_change_gpo(0, RB91X_NAND_NRE_ENABLE);
+       /* enable read mode */
+       gpio_set_value_cansleep(rbni->gpio_read, 1);
 
        /* enable latch */
-       rb91x_latch_enable();
+       gpio_set_value_cansleep(rbni->gpio_nle, 0);
 
+       /* save registers */
+       oe_reg = __raw_readl(base + AR71XX_GPIO_REG_OE);
        out_reg = __raw_readl(base + AR71XX_GPIO_REG_OUT);
 
        /* set data lines to input mode */
@@ -215,109 +177,169 @@ static void rb91x_nand_read(u8 *read_buf, unsigned len)
        }
 
        /* restore  registers */
-       __raw_writel(oe_reg, base + AR71XX_GPIO_REG_OE);
        __raw_writel(out_reg, base + AR71XX_GPIO_REG_OUT);
+       __raw_writel(oe_reg, base + AR71XX_GPIO_REG_OE);
        /* flush write */
        __raw_readl(base + AR71XX_GPIO_REG_OUT);
 
        /* disable latch */
-       rb91x_latch_disable();
+       gpio_set_value_cansleep(rbni->gpio_nle, 1);
 
-       /* deselect nRE mode */
-       rb91x_change_gpo(RB91X_NAND_NRE_ENABLE, 0);
+       /* disable read mode */
+       gpio_set_value_cansleep(rbni->gpio_read, 0);
 }
 
 static int rb91x_nand_dev_ready(struct mtd_info *mtd)
 {
-       void __iomem *base = ath79_gpio_base;
+       struct rb91x_nand_info *rbni = mtd_to_rbinfo(mtd);
 
-       return !!(__raw_readl(base + AR71XX_GPIO_REG_IN) & RB91X_NAND_RDY);
+       return gpio_get_value_cansleep(rbni->gpio_rdy);
 }
 
 static void rb91x_nand_cmd_ctrl(struct mtd_info *mtd, int cmd,
                                unsigned int ctrl)
 {
-       if (ctrl & NAND_CTRL_CHANGE) {
-               u32 on = 0;
-               u32 off;
-
-               if (!(ctrl & NAND_NCE))
-                       on |= RB91X_NAND_NCE;
-
-               if (ctrl & NAND_CLE)
-                       on |= RB91X_NAND_CLE;
-
-               if (ctrl & NAND_ALE)
-                       on |= RB91X_NAND_ALE;
+       struct rb91x_nand_info *rbni = mtd_to_rbinfo(mtd);
 
-               off = on ^ (RB91X_NAND_ALE | RB91X_NAND_NCE | RB91X_NAND_CLE);
-               rb91x_change_gpo(off, on);
+       if (ctrl & NAND_CTRL_CHANGE) {
+               gpio_set_value_cansleep(rbni->gpio_cle,
+                                       (ctrl & NAND_CLE) ? 1 : 0);
+               gpio_set_value_cansleep(rbni->gpio_ale,
+                                       (ctrl & NAND_ALE) ? 1 : 0);
+               gpio_set_value_cansleep(rbni->gpio_nce,
+                                       (ctrl & NAND_NCE) ? 0 : 1);
        }
 
        if (cmd != NAND_CMD_NONE) {
                u8 t = cmd;
 
-               rb91x_nand_write(&t, 1);
+               rb91x_nand_write(rbni, &t, 1);
        }
 }
 
 static u8 rb91x_nand_read_byte(struct mtd_info *mtd)
 {
+       struct rb91x_nand_info *rbni = mtd_to_rbinfo(mtd);
        u8 data = 0xff;
 
-       rb91x_nand_read(&data, 1);
+       rb91x_nand_read(rbni, &data, 1);
 
        return data;
 }
 
 static void rb91x_nand_read_buf(struct mtd_info *mtd, u8 *buf, int len)
 {
-       rb91x_nand_read(buf, len);
+       struct rb91x_nand_info *rbni = mtd_to_rbinfo(mtd);
+
+       rb91x_nand_read(rbni, buf, len);
 }
 
 static void rb91x_nand_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
 {
-       rb91x_nand_write(buf, len);
+       struct rb91x_nand_info *rbni = mtd_to_rbinfo(mtd);
+
+       rb91x_nand_write(rbni, buf, len);
+}
+
+static int rb91x_nand_gpio_init(struct rb91x_nand_info *info)
+{
+       int ret;
+
+       /*
+        * Ensure that the LATCH is disabled before initializing
+        * control lines.
+        */
+       ret = devm_gpio_request_one(info->dev, info->gpio_nle,
+                                   GPIOF_OUT_INIT_HIGH, "LATCH enable");
+       if (ret)
+               return ret;
+
+       ret = devm_gpio_request_one(info->dev, info->gpio_nce,
+                                   GPIOF_OUT_INIT_HIGH, "NAND nCE");
+       if (ret)
+               return ret;
+
+       ret = devm_gpio_request_one(info->dev, info->gpio_nrw,
+                                   GPIOF_OUT_INIT_HIGH, "NAND nRW");
+       if (ret)
+               return ret;
+
+       ret = devm_gpio_request_one(info->dev, info->gpio_cle,
+                                   GPIOF_OUT_INIT_LOW, "NAND CLE");
+       if (ret)
+               return ret;
+
+       ret = devm_gpio_request_one(info->dev, info->gpio_ale,
+                                   GPIOF_OUT_INIT_LOW, "NAND ALE");
+       if (ret)
+               return ret;
+
+       ret = devm_gpio_request_one(info->dev, info->gpio_read,
+                                   GPIOF_OUT_INIT_LOW, "NAND READ");
+       if (ret)
+               return ret;
+
+       ret = devm_gpio_request_one(info->dev, info->gpio_rdy,
+                                   GPIOF_IN, "NAND RDY");
+       return ret;
 }
 
 static int rb91x_nand_probe(struct platform_device *pdev)
 {
-       struct rb91x_nand_info  *info;
+       struct rb91x_nand_info  *rbni;
+       struct rb91x_nand_platform_data *pdata;
        int ret;
 
        pr_info(DRV_DESC "\n");
 
-       info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
-       if (!info)
+       pdata = dev_get_platdata(&pdev->dev);
+       if (!pdata)
+               return -EINVAL;
+
+       rbni = devm_kzalloc(&pdev->dev, sizeof(*rbni), GFP_KERNEL);
+       if (!rbni)
                return -ENOMEM;
 
-       info->chip.priv = &info;
-       info->mtd.priv  = &info->chip;
-       info->mtd.owner = THIS_MODULE;
+       rbni->dev = &pdev->dev;
+       rbni->gpio_nce = pdata->gpio_nce;
+       rbni->gpio_ale = pdata->gpio_ale;
+       rbni->gpio_cle = pdata->gpio_cle;
+       rbni->gpio_read = pdata->gpio_read;
+       rbni->gpio_nrw = pdata->gpio_nrw;
+       rbni->gpio_rdy = pdata->gpio_rdy;
+       rbni->gpio_nle = pdata->gpio_nle;
 
-       info->chip.cmd_ctrl     = rb91x_nand_cmd_ctrl;
-       info->chip.dev_ready    = rb91x_nand_dev_ready;
-       info->chip.read_byte    = rb91x_nand_read_byte;
-       info->chip.write_buf    = rb91x_nand_write_buf;
-       info->chip.read_buf     = rb91x_nand_read_buf;
+       rbni->chip.priv = &rbni;
+       rbni->mtd.priv  = &rbni->chip;
+       rbni->mtd.owner = THIS_MODULE;
 
-       info->chip.chip_delay   = 25;
-       info->chip.ecc.mode     = NAND_ECC_SOFT;
+       rbni->chip.cmd_ctrl     = rb91x_nand_cmd_ctrl;
+       rbni->chip.dev_ready    = rb91x_nand_dev_ready;
+       rbni->chip.read_byte    = rb91x_nand_read_byte;
+       rbni->chip.write_buf    = rb91x_nand_write_buf;
+       rbni->chip.read_buf     = rb91x_nand_read_buf;
 
-       platform_set_drvdata(pdev, info);
+       rbni->chip.chip_delay   = 25;
+       rbni->chip.ecc.mode     = NAND_ECC_SOFT;
 
-       ret = nand_scan_ident(&info->mtd, 1, NULL);
+       platform_set_drvdata(pdev, rbni);
+
+       ret = rb91x_nand_gpio_init(rbni);
        if (ret)
                return ret;
 
-       if (info->mtd.writesize == 512)
-               info->chip.ecc.layout = &rb91x_nand_ecclayout;
+       ret = nand_scan_ident(&rbni->mtd, 1, NULL);
+       if (ret)
+               return ret;
+
+       if (rbni->mtd.writesize == 512)
+               rbni->chip.ecc.layout = &rb91x_nand_ecclayout;
 
-       ret = nand_scan_tail(&info->mtd);
+       ret = nand_scan_tail(&rbni->mtd);
        if (ret)
                return ret;
 
-       ret = mtd_device_register(&info->mtd, rb91x_nand_partitions,
+       ret = mtd_device_register(&rbni->mtd, rb91x_nand_partitions,
                                 ARRAY_SIZE(rb91x_nand_partitions));
        if (ret)
                goto err_release_nand;
@@ -325,7 +347,7 @@ static int rb91x_nand_probe(struct platform_device *pdev)
        return 0;
 
 err_release_nand:
-       nand_release(&info->mtd);
+       nand_release(&rbni->mtd);
        return ret;
 }
 
@@ -342,7 +364,7 @@ static struct platform_driver rb91x_nand_driver = {
        .probe  = rb91x_nand_probe,
        .remove = rb91x_nand_remove,
        .driver = {
-               .name   = DRV_NAME,
+               .name   = RB91X_NAND_DRIVER_NAME,
                .owner  = THIS_MODULE,
        },
 };