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Diffstat (limited to 'arch/arm/mach-mxs/mach-mxs.c')
-rw-r--r--arch/arm/mach-mxs/mach-mxs.c76
1 files changed, 76 insertions, 0 deletions
diff --git a/arch/arm/mach-mxs/mach-mxs.c b/arch/arm/mach-mxs/mach-mxs.c
index 069049200eb4..f346c432cda2 100644
--- a/arch/arm/mach-mxs/mach-mxs.c
+++ b/arch/arm/mach-mxs/mach-mxs.c
@@ -183,6 +183,82 @@ static void __init imx28_timer_init(void)
clocksource_of_init();
}
+#define OCOTP_WORD_OFFSET 0x20
+#define OCOTP_WORD_COUNT 0x20
+
+#define BM_OCOTP_CTRL_BUSY (1 << 8)
+#define BM_OCOTP_CTRL_ERROR (1 << 9)
+#define BM_OCOTP_CTRL_RD_BANK_OPEN (1 << 12)
+
+static DEFINE_MUTEX(ocotp_mutex);
+static u32 ocotp_words[OCOTP_WORD_COUNT];
+
+static const u32 *mxs_get_ocotp(void)
+{
+ struct device_node *np;
+ void __iomem *ocotp_base;
+ int timeout = 0x400;
+ size_t i;
+ static int once;
+
+ if (once)
+ return ocotp_words;
+
+ np = of_find_compatible_node(NULL, NULL, "fsl,ocotp");
+ ocotp_base = of_iomap(np, 0);
+ WARN_ON(!ocotp_base);
+
+ mutex_lock(&ocotp_mutex);
+
+ /*
+ * clk_enable(hbus_clk) for ocotp can be skipped
+ * as it must be on when system is running.
+ */
+
+ /* try to clear ERROR bit */
+ __mxs_clrl(BM_OCOTP_CTRL_ERROR, ocotp_base);
+
+ /* check both BUSY and ERROR cleared */
+ while ((__raw_readl(ocotp_base) &
+ (BM_OCOTP_CTRL_BUSY | BM_OCOTP_CTRL_ERROR)) && --timeout)
+ cpu_relax();
+
+ if (unlikely(!timeout))
+ goto error_unlock;
+
+ /* open OCOTP banks for read */
+ __mxs_setl(BM_OCOTP_CTRL_RD_BANK_OPEN, ocotp_base);
+
+ /* approximately wait 32 hclk cycles */
+ udelay(1);
+
+ /* poll BUSY bit becoming cleared */
+ timeout = 0x400;
+ while ((__raw_readl(ocotp_base) & BM_OCOTP_CTRL_BUSY) && --timeout)
+ cpu_relax();
+
+ if (unlikely(!timeout))
+ goto error_unlock;
+
+ for (i = 0; i < OCOTP_WORD_COUNT; i++)
+ ocotp_words[i] = __raw_readl(ocotp_base + OCOTP_WORD_OFFSET +
+ i * 0x10);
+
+ /* close banks for power saving */
+ __mxs_clrl(BM_OCOTP_CTRL_RD_BANK_OPEN, ocotp_base);
+
+ once = 1;
+
+ mutex_unlock(&ocotp_mutex);
+
+ return ocotp_words;
+
+error_unlock:
+ mutex_unlock(&ocotp_mutex);
+ pr_err("%s: timeout in reading OCOTP\n", __func__);
+ return NULL;
+}
+
enum mac_oui {
OUI_FSL,
OUI_DENX,