memory: omap-gpmc: Prevent GPMC_STATUS from being accessed via gpmc_regs
[cascardo/linux.git] / drivers / memory / omap-gpmc.c
index 21825dd..33d69b1 100644 (file)
@@ -21,7 +21,9 @@
 #include <linux/spinlock.h>
 #include <linux/io.h>
 #include <linux/module.h>
+#include <linux/gpio/driver.h>
 #include <linux/interrupt.h>
+#include <linux/irqdomain.h>
 #include <linux/platform_device.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
@@ -29,7 +31,6 @@
 #include <linux/of_device.h>
 #include <linux/of_platform.h>
 #include <linux/omap-gpmc.h>
-#include <linux/mtd/nand.h>
 #include <linux/pm_runtime.h>
 
 #include <linux/platform_data/mtd-nand-omap2.h>
@@ -81,6 +82,8 @@
 
 #define GPMC_CONFIG_LIMITEDADDRESS             BIT(1)
 
+#define GPMC_STATUS_EMPTYWRITEBUFFERSTATUS     BIT(0)
+
 #define        GPMC_CONFIG2_CSEXTRADELAY               BIT(7)
 #define        GPMC_CONFIG3_ADVEXTRADELAY              BIT(7)
 #define        GPMC_CONFIG4_OEEXTRADELAY               BIT(7)
 #define GPMC_CS_SIZE           0x30
 #define        GPMC_BCH_SIZE           0x10
 
+/*
+ * The first 1MB of GPMC address space is typically mapped to
+ * the internal ROM. Never allocate the first page, to
+ * facilitate bug detection; even if we didn't boot from ROM.
+ * As GPMC minimum partition size is 16MB we can only start from
+ * there.
+ */
+#define GPMC_MEM_START         0x1000000
 #define GPMC_MEM_END           0x3FFFFFFF
 
 #define GPMC_CHUNK_SHIFT       24              /* 16 MB */
 #define GPMC_CONFIG_RDY_BSY    0x00000001
 #define GPMC_CONFIG_DEV_SIZE   0x00000002
 #define GPMC_CONFIG_DEV_TYPE   0x00000003
-#define GPMC_SET_IRQ_STATUS    0x00000004
 
 #define GPMC_CONFIG1_WRAPBURST_SUPP     (1 << 31)
 #define GPMC_CONFIG1_READMULTIPLE_SUPP  (1 << 30)
 #define GPMC_CONFIG_WRITEPROTECT       0x00000010
 #define WR_RD_PIN_MONITORING           0x00600000
 
-#define GPMC_ENABLE_IRQ                0x0000000d
-
 /* ECC commands */
 #define GPMC_ECC_READ          0 /* Reset Hardware ECC for read */
 #define GPMC_ECC_WRITE         1 /* Reset Hardware ECC for write */
 #define GPMC_ECC_READSYN       2 /* Reset before syndrom is read back */
 
-/* XXX: Only NAND irq has been considered,currently these are the only ones used
- */
-#define        GPMC_NR_IRQ             2
+#define        GPMC_NR_NAND_IRQS       2 /* number of NAND specific IRQs */
 
 enum gpmc_clk_domain {
        GPMC_CD_FCLK,
@@ -199,11 +205,6 @@ struct gpmc_cs_data {
        struct resource mem;
 };
 
-struct gpmc_client_irq {
-       unsigned                irq;
-       u32                     bitmask;
-};
-
 /* Structure to save gpmc cs context */
 struct gpmc_cs_config {
        u32 config1;
@@ -231,9 +232,15 @@ struct omap3_gpmc_regs {
        struct gpmc_cs_config cs_context[GPMC_CS_NUM];
 };
 
-static struct gpmc_client_irq gpmc_client_irq[GPMC_NR_IRQ];
-static struct irq_chip gpmc_irq_chip;
-static int gpmc_irq_start;
+struct gpmc_device {
+       struct device *dev;
+       int irq;
+       struct irq_chip irq_chip;
+       struct gpio_chip gpio_chip;
+       int nirqs;
+};
+
+static struct irq_domain *gpmc_irq_domain;
 
 static struct resource gpmc_mem_root;
 static struct gpmc_cs_data gpmc_cs[GPMC_CS_NUM];
@@ -241,8 +248,6 @@ static DEFINE_SPINLOCK(gpmc_mem_lock);
 /* Define chip-selects as reserved by default until probe completes */
 static unsigned int gpmc_cs_num = GPMC_CS_NUM;
 static unsigned int gpmc_nr_waitpins;
-static struct device *gpmc_dev;
-static int gpmc_irq;
 static resource_size_t phys_base, mem_size;
 static unsigned gpmc_capability;
 static void __iomem *gpmc_base;
@@ -1054,14 +1059,6 @@ int gpmc_configure(int cmd, int wval)
        u32 regval;
 
        switch (cmd) {
-       case GPMC_ENABLE_IRQ:
-               gpmc_write_reg(GPMC_IRQENABLE, wval);
-               break;
-
-       case GPMC_SET_IRQ_STATUS:
-               gpmc_write_reg(GPMC_IRQSTATUS, wval);
-               break;
-
        case GPMC_CONFIG_WP:
                regval = gpmc_read_reg(GPMC_CONFIG);
                if (wval)
@@ -1084,7 +1081,7 @@ void gpmc_update_nand_reg(struct gpmc_nand_regs *reg, int cs)
 {
        int i;
 
-       reg->gpmc_status = gpmc_base + GPMC_STATUS;
+       reg->gpmc_status = NULL;        /* deprecated */
        reg->gpmc_nand_command = gpmc_base + GPMC_CS0_OFFSET +
                                GPMC_CS_NAND_COMMAND + GPMC_CS_SIZE * cs;
        reg->gpmc_nand_address = gpmc_base + GPMC_CS0_OFFSET +
@@ -1118,87 +1115,201 @@ void gpmc_update_nand_reg(struct gpmc_nand_regs *reg, int cs)
        }
 }
 
-int gpmc_get_client_irq(unsigned irq_config)
+static bool gpmc_nand_writebuffer_empty(void)
 {
-       int i;
+       if (gpmc_read_reg(GPMC_STATUS) & GPMC_STATUS_EMPTYWRITEBUFFERSTATUS)
+               return true;
 
-       if (hweight32(irq_config) > 1)
+       return false;
+}
+
+static struct gpmc_nand_ops nand_ops = {
+       .nand_writebuffer_empty = gpmc_nand_writebuffer_empty,
+};
+
+/**
+ * gpmc_omap_get_nand_ops - Get the GPMC NAND interface
+ * @regs: the GPMC NAND register map exclusive for NAND use.
+ * @cs: GPMC chip select number on which the NAND sits. The
+ *      register map returned will be specific to this chip select.
+ *
+ * Returns NULL on error e.g. invalid cs.
+ */
+struct gpmc_nand_ops *gpmc_omap_get_nand_ops(struct gpmc_nand_regs *reg, int cs)
+{
+       if (cs >= gpmc_cs_num)
+               return NULL;
+
+       gpmc_update_nand_reg(reg, cs);
+
+       return &nand_ops;
+}
+EXPORT_SYMBOL_GPL(gpmc_omap_get_nand_ops);
+
+int gpmc_get_client_irq(unsigned irq_config)
+{
+       if (!gpmc_irq_domain) {
+               pr_warn("%s called before GPMC IRQ domain available\n",
+                       __func__);
                return 0;
+       }
 
-       for (i = 0; i < GPMC_NR_IRQ; i++)
-               if (gpmc_client_irq[i].bitmask & irq_config)
-                       return gpmc_client_irq[i].irq;
+       /* we restrict this to NAND IRQs only */
+       if (irq_config >= GPMC_NR_NAND_IRQS)
+               return 0;
 
-       return 0;
+       return irq_create_mapping(gpmc_irq_domain, irq_config);
 }
 
-static int gpmc_irq_endis(unsigned irq, bool endis)
+static int gpmc_irq_endis(unsigned long hwirq, bool endis)
 {
-       int i;
        u32 regval;
 
-       for (i = 0; i < GPMC_NR_IRQ; i++)
-               if (irq == gpmc_client_irq[i].irq) {
-                       regval = gpmc_read_reg(GPMC_IRQENABLE);
-                       if (endis)
-                               regval |= gpmc_client_irq[i].bitmask;
-                       else
-                               regval &= ~gpmc_client_irq[i].bitmask;
-                       gpmc_write_reg(GPMC_IRQENABLE, regval);
-                       break;
-               }
+       /* bits GPMC_NR_NAND_IRQS to 8 are reserved */
+       if (hwirq >= GPMC_NR_NAND_IRQS)
+               hwirq += 8 - GPMC_NR_NAND_IRQS;
+
+       regval = gpmc_read_reg(GPMC_IRQENABLE);
+       if (endis)
+               regval |= BIT(hwirq);
+       else
+               regval &= ~BIT(hwirq);
+       gpmc_write_reg(GPMC_IRQENABLE, regval);
 
        return 0;
 }
 
 static void gpmc_irq_disable(struct irq_data *p)
 {
-       gpmc_irq_endis(p->irq, false);
+       gpmc_irq_endis(p->hwirq, false);
 }
 
 static void gpmc_irq_enable(struct irq_data *p)
 {
-       gpmc_irq_endis(p->irq, true);
+       gpmc_irq_endis(p->hwirq, true);
 }
 
-static void gpmc_irq_noop(struct irq_data *data) { }
+static void gpmc_irq_mask(struct irq_data *d)
+{
+       gpmc_irq_endis(d->hwirq, false);
+}
 
-static unsigned int gpmc_irq_noop_ret(struct irq_data *data) { return 0; }
+static void gpmc_irq_unmask(struct irq_data *d)
+{
+       gpmc_irq_endis(d->hwirq, true);
+}
 
-static int gpmc_setup_irq(void)
+static void gpmc_irq_edge_config(unsigned long hwirq, bool rising_edge)
 {
-       int i;
        u32 regval;
 
-       if (!gpmc_irq)
+       /* NAND IRQs polarity is not configurable */
+       if (hwirq < GPMC_NR_NAND_IRQS)
+               return;
+
+       /* WAITPIN starts at BIT 8 */
+       hwirq += 8 - GPMC_NR_NAND_IRQS;
+
+       regval = gpmc_read_reg(GPMC_CONFIG);
+       if (rising_edge)
+               regval &= ~BIT(hwirq);
+       else
+               regval |= BIT(hwirq);
+
+       gpmc_write_reg(GPMC_CONFIG, regval);
+}
+
+static void gpmc_irq_ack(struct irq_data *d)
+{
+       unsigned int hwirq = d->hwirq;
+
+       /* skip reserved bits */
+       if (hwirq >= GPMC_NR_NAND_IRQS)
+               hwirq += 8 - GPMC_NR_NAND_IRQS;
+
+       /* Setting bit to 1 clears (or Acks) the interrupt */
+       gpmc_write_reg(GPMC_IRQSTATUS, BIT(hwirq));
+}
+
+static int gpmc_irq_set_type(struct irq_data *d, unsigned int trigger)
+{
+       /* can't set type for NAND IRQs */
+       if (d->hwirq < GPMC_NR_NAND_IRQS)
                return -EINVAL;
 
-       gpmc_irq_start = irq_alloc_descs(-1, 0, GPMC_NR_IRQ, 0);
-       if (gpmc_irq_start < 0) {
-               pr_err("irq_alloc_descs failed\n");
-               return gpmc_irq_start;
+       /* We can support either rising or falling edge at a time */
+       if (trigger == IRQ_TYPE_EDGE_FALLING)
+               gpmc_irq_edge_config(d->hwirq, false);
+       else if (trigger == IRQ_TYPE_EDGE_RISING)
+               gpmc_irq_edge_config(d->hwirq, true);
+       else
+               return -EINVAL;
+
+       return 0;
+}
+
+static int gpmc_irq_map(struct irq_domain *d, unsigned int virq,
+                       irq_hw_number_t hw)
+{
+       struct gpmc_device *gpmc = d->host_data;
+
+       irq_set_chip_data(virq, gpmc);
+       if (hw < GPMC_NR_NAND_IRQS) {
+               irq_modify_status(virq, IRQ_NOREQUEST, IRQ_NOAUTOEN);
+               irq_set_chip_and_handler(virq, &gpmc->irq_chip,
+                                        handle_simple_irq);
+       } else {
+               irq_set_chip_and_handler(virq, &gpmc->irq_chip,
+                                        handle_edge_irq);
        }
 
-       gpmc_irq_chip.name = "gpmc";
-       gpmc_irq_chip.irq_startup = gpmc_irq_noop_ret;
-       gpmc_irq_chip.irq_enable = gpmc_irq_enable;
-       gpmc_irq_chip.irq_disable = gpmc_irq_disable;
-       gpmc_irq_chip.irq_shutdown = gpmc_irq_noop;
-       gpmc_irq_chip.irq_ack = gpmc_irq_noop;
-       gpmc_irq_chip.irq_mask = gpmc_irq_noop;
-       gpmc_irq_chip.irq_unmask = gpmc_irq_noop;
-
-       gpmc_client_irq[0].bitmask = GPMC_IRQ_FIFOEVENTENABLE;
-       gpmc_client_irq[1].bitmask = GPMC_IRQ_COUNT_EVENT;
-
-       for (i = 0; i < GPMC_NR_IRQ; i++) {
-               gpmc_client_irq[i].irq = gpmc_irq_start + i;
-               irq_set_chip_and_handler(gpmc_client_irq[i].irq,
-                                       &gpmc_irq_chip, handle_simple_irq);
-               irq_modify_status(gpmc_client_irq[i].irq, IRQ_NOREQUEST,
-                                 IRQ_NOAUTOEN);
+       return 0;
+}
+
+static const struct irq_domain_ops gpmc_irq_domain_ops = {
+       .map    = gpmc_irq_map,
+       .xlate  = irq_domain_xlate_twocell,
+};
+
+static irqreturn_t gpmc_handle_irq(int irq, void *data)
+{
+       int hwirq, virq;
+       u32 regval, regvalx;
+       struct gpmc_device *gpmc = data;
+
+       regval = gpmc_read_reg(GPMC_IRQSTATUS);
+       regvalx = regval;
+
+       if (!regval)
+               return IRQ_NONE;
+
+       for (hwirq = 0; hwirq < gpmc->nirqs; hwirq++) {
+               /* skip reserved status bits */
+               if (hwirq == GPMC_NR_NAND_IRQS)
+                       regvalx >>= 8 - GPMC_NR_NAND_IRQS;
+
+               if (regvalx & BIT(hwirq)) {
+                       virq = irq_find_mapping(gpmc_irq_domain, hwirq);
+                       if (!virq) {
+                               dev_warn(gpmc->dev,
+                                        "spurious irq detected hwirq %d, virq %d\n",
+                                        hwirq, virq);
+                       }
+
+                       generic_handle_irq(virq);
+               }
        }
 
+       gpmc_write_reg(GPMC_IRQSTATUS, regval);
+
+       return IRQ_HANDLED;
+}
+
+static int gpmc_setup_irq(struct gpmc_device *gpmc)
+{
+       u32 regval;
+       int rc;
+
        /* Disable interrupts */
        gpmc_write_reg(GPMC_IRQENABLE, 0);
 
@@ -1206,22 +1317,45 @@ static int gpmc_setup_irq(void)
        regval = gpmc_read_reg(GPMC_IRQSTATUS);
        gpmc_write_reg(GPMC_IRQSTATUS, regval);
 
-       return request_irq(gpmc_irq, gpmc_handle_irq, 0, "gpmc", NULL);
+       gpmc->irq_chip.name = "gpmc";
+       gpmc->irq_chip.irq_enable = gpmc_irq_enable;
+       gpmc->irq_chip.irq_disable = gpmc_irq_disable;
+       gpmc->irq_chip.irq_ack = gpmc_irq_ack;
+       gpmc->irq_chip.irq_mask = gpmc_irq_mask;
+       gpmc->irq_chip.irq_unmask = gpmc_irq_unmask;
+       gpmc->irq_chip.irq_set_type = gpmc_irq_set_type;
+
+       gpmc_irq_domain = irq_domain_add_linear(gpmc->dev->of_node,
+                                               gpmc->nirqs,
+                                               &gpmc_irq_domain_ops,
+                                               gpmc);
+       if (!gpmc_irq_domain) {
+               dev_err(gpmc->dev, "IRQ domain add failed\n");
+               return -ENODEV;
+       }
+
+       rc = request_irq(gpmc->irq, gpmc_handle_irq, 0, "gpmc", gpmc);
+       if (rc) {
+               dev_err(gpmc->dev, "failed to request irq %d: %d\n",
+                       gpmc->irq, rc);
+               irq_domain_remove(gpmc_irq_domain);
+               gpmc_irq_domain = NULL;
+       }
+
+       return rc;
 }
 
-static int gpmc_free_irq(void)
+static int gpmc_free_irq(struct gpmc_device *gpmc)
 {
-       int i;
+       int hwirq;
 
-       if (gpmc_irq)
-               free_irq(gpmc_irq, NULL);
+       free_irq(gpmc->irq, gpmc);
 
-       for (i = 0; i < GPMC_NR_IRQ; i++) {
-               irq_set_handler(gpmc_client_irq[i].irq, NULL);
-               irq_set_chip(gpmc_client_irq[i].irq, &no_irq_chip);
-       }
+       for (hwirq = 0; hwirq < gpmc->nirqs; hwirq++)
+               irq_dispose_mapping(irq_find_mapping(gpmc_irq_domain, hwirq));
 
-       irq_free_descs(gpmc_irq_start, GPMC_NR_IRQ);
+       irq_domain_remove(gpmc_irq_domain);
+       gpmc_irq_domain = NULL;
 
        return 0;
 }
@@ -1242,12 +1376,7 @@ static void gpmc_mem_init(void)
 {
        int cs;
 
-       /*
-        * The first 1MB of GPMC address space is typically mapped to
-        * the internal ROM. Never allocate the first page, to
-        * facilitate bug detection; even if we didn't boot from ROM.
-        */
-       gpmc_mem_root.start = SZ_1M;
+       gpmc_mem_root.start = GPMC_MEM_START;
        gpmc_mem_root.end = GPMC_MEM_END;
 
        /* Reserve all regions that has been set up by bootloader */
@@ -1796,105 +1925,6 @@ static void __maybe_unused gpmc_read_timings_dt(struct device_node *np,
                of_property_read_bool(np, "gpmc,time-para-granularity");
 }
 
-#if IS_ENABLED(CONFIG_MTD_NAND)
-
-static const char * const nand_xfer_types[] = {
-       [NAND_OMAP_PREFETCH_POLLED]             = "prefetch-polled",
-       [NAND_OMAP_POLLED]                      = "polled",
-       [NAND_OMAP_PREFETCH_DMA]                = "prefetch-dma",
-       [NAND_OMAP_PREFETCH_IRQ]                = "prefetch-irq",
-};
-
-static int gpmc_probe_nand_child(struct platform_device *pdev,
-                                struct device_node *child)
-{
-       u32 val;
-       const char *s;
-       struct gpmc_timings gpmc_t;
-       struct omap_nand_platform_data *gpmc_nand_data;
-
-       if (of_property_read_u32(child, "reg", &val) < 0) {
-               dev_err(&pdev->dev, "%s has no 'reg' property\n",
-                       child->full_name);
-               return -ENODEV;
-       }
-
-       gpmc_nand_data = devm_kzalloc(&pdev->dev, sizeof(*gpmc_nand_data),
-                                     GFP_KERNEL);
-       if (!gpmc_nand_data)
-               return -ENOMEM;
-
-       gpmc_nand_data->cs = val;
-       gpmc_nand_data->of_node = child;
-
-       /* Detect availability of ELM module */
-       gpmc_nand_data->elm_of_node = of_parse_phandle(child, "ti,elm-id", 0);
-       if (gpmc_nand_data->elm_of_node == NULL)
-               gpmc_nand_data->elm_of_node =
-                                       of_parse_phandle(child, "elm_id", 0);
-
-       /* select ecc-scheme for NAND */
-       if (of_property_read_string(child, "ti,nand-ecc-opt", &s)) {
-               pr_err("%s: ti,nand-ecc-opt not found\n", __func__);
-               return -ENODEV;
-       }
-
-       if (!strcmp(s, "sw"))
-               gpmc_nand_data->ecc_opt = OMAP_ECC_HAM1_CODE_SW;
-       else if (!strcmp(s, "ham1") ||
-                !strcmp(s, "hw") || !strcmp(s, "hw-romcode"))
-               gpmc_nand_data->ecc_opt =
-                               OMAP_ECC_HAM1_CODE_HW;
-       else if (!strcmp(s, "bch4"))
-               if (gpmc_nand_data->elm_of_node)
-                       gpmc_nand_data->ecc_opt =
-                               OMAP_ECC_BCH4_CODE_HW;
-               else
-                       gpmc_nand_data->ecc_opt =
-                               OMAP_ECC_BCH4_CODE_HW_DETECTION_SW;
-       else if (!strcmp(s, "bch8"))
-               if (gpmc_nand_data->elm_of_node)
-                       gpmc_nand_data->ecc_opt =
-                               OMAP_ECC_BCH8_CODE_HW;
-               else
-                       gpmc_nand_data->ecc_opt =
-                               OMAP_ECC_BCH8_CODE_HW_DETECTION_SW;
-       else if (!strcmp(s, "bch16"))
-               if (gpmc_nand_data->elm_of_node)
-                       gpmc_nand_data->ecc_opt =
-                               OMAP_ECC_BCH16_CODE_HW;
-               else
-                       pr_err("%s: BCH16 requires ELM support\n", __func__);
-       else
-               pr_err("%s: ti,nand-ecc-opt invalid value\n", __func__);
-
-       /* select data transfer mode for NAND controller */
-       if (!of_property_read_string(child, "ti,nand-xfer-type", &s))
-               for (val = 0; val < ARRAY_SIZE(nand_xfer_types); val++)
-                       if (!strcasecmp(s, nand_xfer_types[val])) {
-                               gpmc_nand_data->xfer_type = val;
-                               break;
-                       }
-
-       gpmc_nand_data->flash_bbt = of_get_nand_on_flash_bbt(child);
-
-       val = of_get_nand_bus_width(child);
-       if (val == 16)
-               gpmc_nand_data->devsize = NAND_BUSWIDTH_16;
-
-       gpmc_read_timings_dt(child, &gpmc_t);
-       gpmc_nand_init(gpmc_nand_data, &gpmc_t);
-
-       return 0;
-}
-#else
-static int gpmc_probe_nand_child(struct platform_device *pdev,
-                                struct device_node *child)
-{
-       return 0;
-}
-#endif
-
 #if IS_ENABLED(CONFIG_MTD_ONENAND)
 static int gpmc_probe_onenand_child(struct platform_device *pdev,
                                 struct device_node *child)
@@ -1950,6 +1980,8 @@ static int gpmc_probe_generic_child(struct platform_device *pdev,
        const char *name;
        int ret, cs;
        u32 val;
+       struct gpio_desc *waitpin_desc = NULL;
+       struct gpmc_device *gpmc = platform_get_drvdata(pdev);
 
        if (of_property_read_u32(child, "reg", &cs) < 0) {
                dev_err(&pdev->dev, "%s has no 'reg' property\n",
@@ -2010,23 +2042,79 @@ static int gpmc_probe_generic_child(struct platform_device *pdev,
        if (ret < 0) {
                dev_err(&pdev->dev, "cannot remap GPMC CS %d to %pa\n",
                        cs, &res.start);
+               if (res.start < GPMC_MEM_START) {
+                       dev_info(&pdev->dev,
+                                "GPMC CS %d start cannot be lesser than 0x%x\n",
+                                cs, GPMC_MEM_START);
+               } else if (res.end > GPMC_MEM_END) {
+                       dev_info(&pdev->dev,
+                                "GPMC CS %d end cannot be greater than 0x%x\n",
+                                cs, GPMC_MEM_END);
+               }
                goto err;
        }
 
-       ret = of_property_read_u32(child, "bank-width", &gpmc_s.device_width);
-       if (ret < 0)
-               goto err;
+       if (of_node_cmp(child->name, "nand") == 0) {
+               /* Warn about older DT blobs with no compatible property */
+               if (!of_property_read_bool(child, "compatible")) {
+                       dev_warn(&pdev->dev,
+                                "Incompatible NAND node: missing compatible");
+                       ret = -EINVAL;
+                       goto err;
+               }
+       }
+
+       if (of_device_is_compatible(child, "ti,omap2-nand")) {
+               /* NAND specific setup */
+               val = of_get_nand_bus_width(child);
+               switch (val) {
+               case 8:
+                       gpmc_s.device_width = GPMC_DEVWIDTH_8BIT;
+                       break;
+               case 16:
+                       gpmc_s.device_width = GPMC_DEVWIDTH_16BIT;
+                       break;
+               default:
+                       dev_err(&pdev->dev, "%s: invalid 'nand-bus-width'\n",
+                               child->name);
+                       ret = -EINVAL;
+                       goto err;
+               }
+
+               /* disable write protect */
+               gpmc_configure(GPMC_CONFIG_WP, 0);
+               gpmc_s.device_nand = true;
+       } else {
+               ret = of_property_read_u32(child, "bank-width",
+                                          &gpmc_s.device_width);
+               if (ret < 0)
+                       goto err;
+       }
+
+       /* Reserve wait pin if it is required and valid */
+       if (gpmc_s.wait_on_read || gpmc_s.wait_on_write) {
+               unsigned int wait_pin = gpmc_s.wait_pin;
+
+               waitpin_desc = gpiochip_request_own_desc(&gpmc->gpio_chip,
+                                                        wait_pin, "WAITPIN");
+               if (IS_ERR(waitpin_desc)) {
+                       dev_err(&pdev->dev, "invalid wait-pin: %d\n", wait_pin);
+                       ret = PTR_ERR(waitpin_desc);
+                       goto err;
+               }
+       }
 
        gpmc_cs_show_timings(cs, "before gpmc_cs_program_settings");
+
        ret = gpmc_cs_program_settings(cs, &gpmc_s);
        if (ret < 0)
-               goto err;
+               goto err_cs;
 
        ret = gpmc_cs_set_timings(cs, &gpmc_t, &gpmc_s);
        if (ret) {
                dev_err(&pdev->dev, "failed to set gpmc timings for: %s\n",
                        child->name);
-               goto err;
+               goto err_cs;
        }
 
        /* Clear limited address i.e. enable A26-A11 */
@@ -2057,16 +2145,81 @@ err_child_fail:
        dev_err(&pdev->dev, "failed to create gpmc child %s\n", child->name);
        ret = -ENODEV;
 
+err_cs:
+       if (waitpin_desc)
+               gpiochip_free_own_desc(waitpin_desc);
+
 err:
        gpmc_cs_free(cs);
 
        return ret;
 }
 
+static int gpmc_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
+{
+       return 1;       /* we're input only */
+}
+
+static int gpmc_gpio_direction_input(struct gpio_chip *chip,
+                                    unsigned int offset)
+{
+       return 0;       /* we're input only */
+}
+
+static int gpmc_gpio_direction_output(struct gpio_chip *chip,
+                                     unsigned int offset, int value)
+{
+       return -EINVAL; /* we're input only */
+}
+
+static void gpmc_gpio_set(struct gpio_chip *chip, unsigned int offset,
+                         int value)
+{
+}
+
+static int gpmc_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+       u32 reg;
+
+       offset += 8;
+
+       reg = gpmc_read_reg(GPMC_STATUS) & BIT(offset);
+
+       return !!reg;
+}
+
+static int gpmc_gpio_init(struct gpmc_device *gpmc)
+{
+       int ret;
+
+       gpmc->gpio_chip.parent = gpmc->dev;
+       gpmc->gpio_chip.owner = THIS_MODULE;
+       gpmc->gpio_chip.label = DEVICE_NAME;
+       gpmc->gpio_chip.ngpio = gpmc_nr_waitpins;
+       gpmc->gpio_chip.get_direction = gpmc_gpio_get_direction;
+       gpmc->gpio_chip.direction_input = gpmc_gpio_direction_input;
+       gpmc->gpio_chip.direction_output = gpmc_gpio_direction_output;
+       gpmc->gpio_chip.set = gpmc_gpio_set;
+       gpmc->gpio_chip.get = gpmc_gpio_get;
+       gpmc->gpio_chip.base = -1;
+
+       ret = gpiochip_add(&gpmc->gpio_chip);
+       if (ret < 0) {
+               dev_err(gpmc->dev, "could not register gpio chip: %d\n", ret);
+               return ret;
+       }
+
+       return 0;
+}
+
+static void gpmc_gpio_exit(struct gpmc_device *gpmc)
+{
+       gpiochip_remove(&gpmc->gpio_chip);
+}
+
 static int gpmc_probe_dt(struct platform_device *pdev)
 {
        int ret;
-       struct device_node *child;
        const struct of_device_id *of_id =
                of_match_device(gpmc_dt_ids, &pdev->dev);
 
@@ -2094,17 +2247,26 @@ static int gpmc_probe_dt(struct platform_device *pdev)
                return ret;
        }
 
+       return 0;
+}
+
+static int gpmc_probe_dt_children(struct platform_device *pdev)
+{
+       int ret;
+       struct device_node *child;
+
        for_each_available_child_of_node(pdev->dev.of_node, child) {
 
                if (!child->name)
                        continue;
 
-               if (of_node_cmp(child->name, "nand") == 0)
-                       ret = gpmc_probe_nand_child(pdev, child);
-               else if (of_node_cmp(child->name, "onenand") == 0)
+               if (of_node_cmp(child->name, "onenand") == 0)
                        ret = gpmc_probe_onenand_child(pdev, child);
                else
                        ret = gpmc_probe_generic_child(pdev, child);
+
+               if (ret)
+                       return ret;
        }
 
        return 0;
@@ -2114,6 +2276,11 @@ static int gpmc_probe_dt(struct platform_device *pdev)
 {
        return 0;
 }
+
+static int gpmc_probe_dt_children(struct platform_device *pdev)
+{
+       return 0;
+}
 #endif
 
 static int gpmc_probe(struct platform_device *pdev)
@@ -2121,6 +2288,14 @@ static int gpmc_probe(struct platform_device *pdev)
        int rc;
        u32 l;
        struct resource *res;
+       struct gpmc_device *gpmc;
+
+       gpmc = devm_kzalloc(&pdev->dev, sizeof(*gpmc), GFP_KERNEL);
+       if (!gpmc)
+               return -ENOMEM;
+
+       gpmc->dev = &pdev->dev;
+       platform_set_drvdata(pdev, gpmc);
 
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (res == NULL)
@@ -2134,15 +2309,16 @@ static int gpmc_probe(struct platform_device *pdev)
                return PTR_ERR(gpmc_base);
 
        res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-       if (res == NULL)
-               dev_warn(&pdev->dev, "Failed to get resource: irq\n");
-       else
-               gpmc_irq = res->start;
+       if (!res) {
+               dev_err(&pdev->dev, "Failed to get resource: irq\n");
+               return -ENOENT;
+       }
+
+       gpmc->irq = res->start;
 
        gpmc_l3_clk = devm_clk_get(&pdev->dev, "fck");
        if (IS_ERR(gpmc_l3_clk)) {
                dev_err(&pdev->dev, "Failed to get GPMC fck\n");
-               gpmc_irq = 0;
                return PTR_ERR(gpmc_l3_clk);
        }
 
@@ -2151,11 +2327,18 @@ static int gpmc_probe(struct platform_device *pdev)
                return -EINVAL;
        }
 
+       if (pdev->dev.of_node) {
+               rc = gpmc_probe_dt(pdev);
+               if (rc)
+                       return rc;
+       } else {
+               gpmc_cs_num = GPMC_CS_NUM;
+               gpmc_nr_waitpins = GPMC_NR_WAITPINS;
+       }
+
        pm_runtime_enable(&pdev->dev);
        pm_runtime_get_sync(&pdev->dev);
 
-       gpmc_dev = &pdev->dev;
-
        l = gpmc_read_reg(GPMC_REVISION);
 
        /*
@@ -2174,36 +2357,51 @@ static int gpmc_probe(struct platform_device *pdev)
                gpmc_capability = GPMC_HAS_WR_ACCESS | GPMC_HAS_WR_DATA_MUX_BUS;
        if (GPMC_REVISION_MAJOR(l) > 0x5)
                gpmc_capability |= GPMC_HAS_MUX_AAD;
-       dev_info(gpmc_dev, "GPMC revision %d.%d\n", GPMC_REVISION_MAJOR(l),
+       dev_info(gpmc->dev, "GPMC revision %d.%d\n", GPMC_REVISION_MAJOR(l),
                 GPMC_REVISION_MINOR(l));
 
        gpmc_mem_init();
-
-       if (gpmc_setup_irq() < 0)
-               dev_warn(gpmc_dev, "gpmc_setup_irq failed\n");
-
-       if (!pdev->dev.of_node) {
-               gpmc_cs_num      = GPMC_CS_NUM;
-               gpmc_nr_waitpins = GPMC_NR_WAITPINS;
+       rc = gpmc_gpio_init(gpmc);
+       if (rc)
+               goto gpio_init_failed;
+
+       gpmc->nirqs = GPMC_NR_NAND_IRQS + gpmc_nr_waitpins;
+       rc = gpmc_setup_irq(gpmc);
+       if (rc) {
+               dev_err(gpmc->dev, "gpmc_setup_irq failed\n");
+               goto setup_irq_failed;
        }
 
-       rc = gpmc_probe_dt(pdev);
+       rc = gpmc_probe_dt_children(pdev);
        if (rc < 0) {
-               pm_runtime_put_sync(&pdev->dev);
-               dev_err(gpmc_dev, "failed to probe DT parameters\n");
-               return rc;
+               dev_err(gpmc->dev, "failed to probe DT children\n");
+               goto dt_children_failed;
        }
 
        return 0;
+
+dt_children_failed:
+       gpmc_free_irq(gpmc);
+setup_irq_failed:
+       gpmc_gpio_exit(gpmc);
+gpio_init_failed:
+       gpmc_mem_exit();
+       pm_runtime_put_sync(&pdev->dev);
+       pm_runtime_disable(&pdev->dev);
+
+       return rc;
 }
 
 static int gpmc_remove(struct platform_device *pdev)
 {
-       gpmc_free_irq();
+       struct gpmc_device *gpmc = platform_get_drvdata(pdev);
+
+       gpmc_free_irq(gpmc);
+       gpmc_gpio_exit(gpmc);
        gpmc_mem_exit();
        pm_runtime_put_sync(&pdev->dev);
        pm_runtime_disable(&pdev->dev);
-       gpmc_dev = NULL;
+
        return 0;
 }
 
@@ -2249,25 +2447,6 @@ static __exit void gpmc_exit(void)
 postcore_initcall(gpmc_init);
 module_exit(gpmc_exit);
 
-static irqreturn_t gpmc_handle_irq(int irq, void *dev)
-{
-       int i;
-       u32 regval;
-
-       regval = gpmc_read_reg(GPMC_IRQSTATUS);
-
-       if (!regval)
-               return IRQ_NONE;
-
-       for (i = 0; i < GPMC_NR_IRQ; i++)
-               if (regval & gpmc_client_irq[i].bitmask)
-                       generic_handle_irq(gpmc_client_irq[i].irq);
-
-       gpmc_write_reg(GPMC_IRQSTATUS, regval);
-
-       return IRQ_HANDLED;
-}
-
 static struct omap3_gpmc_regs gpmc_context;
 
 void omap3_gpmc_save_context(void)