mtd: mxc_nand: add support for multiple chips on V21 devices

Do the following to add support for up to 4 chips on V21 devices (i.MX25 and
i.MX35):

* implement .select_chip for V21
* adjust existing NFC_V1_V2_BUF_ADDR writes to take chip select into account
* unlock all chip selects at preset_v1_v2()
* scan up to 4 devices at .probe

This has been tested on i.MX25 with two attached NAND chip (on one die).

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index 42a95fb..b4efdb7 100644 (file)
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -56,8 +56,14 @@
 #define NFC_V1_V2_WRPROT               (host->regs + 0x12)
 #define NFC_V1_UNLOCKSTART_BLKADDR     (host->regs + 0x14)
 #define NFC_V1_UNLOCKEND_BLKADDR       (host->regs + 0x16)
-#define NFC_V21_UNLOCKSTART_BLKADDR    (host->regs + 0x20)
-#define NFC_V21_UNLOCKEND_BLKADDR      (host->regs + 0x22)
+#define NFC_V21_UNLOCKSTART_BLKADDR0   (host->regs + 0x20)
+#define NFC_V21_UNLOCKSTART_BLKADDR1   (host->regs + 0x24)
+#define NFC_V21_UNLOCKSTART_BLKADDR2   (host->regs + 0x28)
+#define NFC_V21_UNLOCKSTART_BLKADDR3   (host->regs + 0x2c)
+#define NFC_V21_UNLOCKEND_BLKADDR0     (host->regs + 0x22)
+#define NFC_V21_UNLOCKEND_BLKADDR1     (host->regs + 0x26)
+#define NFC_V21_UNLOCKEND_BLKADDR2     (host->regs + 0x2a)
+#define NFC_V21_UNLOCKEND_BLKADDR3     (host->regs + 0x2e)
 #define NFC_V1_V2_NF_WRPRST            (host->regs + 0x18)
 #define NFC_V1_V2_CONFIG1              (host->regs + 0x1a)
 #define NFC_V1_V2_CONFIG2              (host->regs + 0x1c)
@@ -152,6 +158,7 @@ struct mxc_nand_host {
        int                     clk_act;
        int                     irq;
        int                     eccsize;
+       int                     active_cs;
 
        struct completion       op_completion;
 
@@ -445,7 +452,7 @@ static void send_page_v1_v2(struct mtd_info *mtd, unsigned int ops)
        for (i = 0; i < bufs; i++) {
 
                /* NANDFC buffer 0 is used for page read/write */
-               writew(i, NFC_V1_V2_BUF_ADDR);
+               writew((host->active_cs << 4) | i, NFC_V1_V2_BUF_ADDR);
 
                writew(ops, NFC_V1_V2_CONFIG2);
 
@@ -470,7 +477,7 @@ static void send_read_id_v1_v2(struct mxc_nand_host *host)
        struct nand_chip *this = &host->nand;
 
        /* NANDFC buffer 0 is used for device ID output */
-       writew(0x0, NFC_V1_V2_BUF_ADDR);
+       writew(host->active_cs << 4, NFC_V1_V2_BUF_ADDR);
 
        writew(NFC_ID, NFC_V1_V2_CONFIG2);
 
@@ -505,7 +512,7 @@ static uint16_t get_dev_status_v1_v2(struct mxc_nand_host *host)
        uint32_t store;
        uint16_t ret;
 
-       writew(0x0, NFC_V1_V2_BUF_ADDR);
+       writew(host->active_cs << 4, NFC_V1_V2_BUF_ADDR);
 
        /*
         * The device status is stored in main_area0. To
@@ -686,24 +693,24 @@ static void mxc_nand_select_chip(struct mtd_info *mtd, int chip)
        struct nand_chip *nand_chip = mtd->priv;
        struct mxc_nand_host *host = nand_chip->priv;
 
-       switch (chip) {
-       case -1:
+       if (chip == -1) {
                /* Disable the NFC clock */
                if (host->clk_act) {
                        clk_disable(host->clk);
                        host->clk_act = 0;
                }
-               break;
-       case 0:
+               return;
+       }
+
+       if (!host->clk_act) {
                /* Enable the NFC clock */
-               if (!host->clk_act) {
-                       clk_enable(host->clk);
-                       host->clk_act = 1;
-               }
-               break;
+               clk_enable(host->clk);
+               host->clk_act = 1;
+       }
 
-       default:
-               break;
+       if (nfc_is_v21()) {
+               host->active_cs = chip;
+               writew(host->active_cs << 4, NFC_V1_V2_BUF_ADDR);
        }
 }
 
@@ -834,8 +841,14 @@ static void preset_v1_v2(struct mtd_info *mtd)
 
        /* Blocks to be unlocked */
        if (nfc_is_v21()) {
-               writew(0x0, NFC_V21_UNLOCKSTART_BLKADDR);
-               writew(0xffff, NFC_V21_UNLOCKEND_BLKADDR);
+               writew(0x0, NFC_V21_UNLOCKSTART_BLKADDR0);
+               writew(0x0, NFC_V21_UNLOCKSTART_BLKADDR1);
+               writew(0x0, NFC_V21_UNLOCKSTART_BLKADDR2);
+               writew(0x0, NFC_V21_UNLOCKSTART_BLKADDR3);
+               writew(0xffff, NFC_V21_UNLOCKEND_BLKADDR0);
+               writew(0xffff, NFC_V21_UNLOCKEND_BLKADDR1);
+               writew(0xffff, NFC_V21_UNLOCKEND_BLKADDR2);
+               writew(0xffff, NFC_V21_UNLOCKEND_BLKADDR3);
        } else if (nfc_is_v1()) {
                writew(0x0, NFC_V1_UNLOCKSTART_BLKADDR);
                writew(0x4000, NFC_V1_UNLOCKEND_BLKADDR);
@@ -1200,7 +1213,7 @@ static int __init mxcnd_probe(struct platform_device *pdev)
                irq_control_v1_v2(host, 1);
 
        /* first scan to find the device and get the page size */
-       if (nand_scan_ident(mtd, 1, NULL)) {
+       if (nand_scan_ident(mtd, nfc_is_v21() ? 4 : 1, NULL)) {
                err = -ENXIO;
                goto escan;
        }