[PATCH v2] hvc_dcc : add support to armv4 and armv5 core
From: Stephen Boyd <hidden>
Date: 2012-08-31 16:49:14
Also in:
lkml
On 8/31/2012 4:47 AM, Matthieu CASTET wrote:
Signed-off-by: Matthieu Castet <redacted>
Please consider adding some sort of commit text. Does this add some new feature I may want on some downstream distro kernel?
quoted hunk ↗ jump to hunk
@@ -51,7 +51,7 @@ static inline char __dcc_getchar(void) return __c; } -static inline void __dcc_putchar(char c) +static inline void __dcc_putchar_v6(char c) { asm volatile("mcr p14, 0, %0, c0, c5, 0 @ write a char" : /* no output register */@@ -59,6 +59,69 @@ static inline void __dcc_putchar(char c) isb(); } +static int hvc_dcc_put_chars_v6(uint32_t vt, const char *buf, int count) +{ + int i; + + for (i = 0; i < count; i++) { + while (__dcc_getstatus_v6() & DCC_STATUS_TX_V6) + cpu_relax(); + + __dcc_putchar_v6(buf[i]); + } + + return count; +}
It's unfortunate that the main logic is duplicated. I wonder if we could push the runtime decision slightly lower into the accessor functions instead and make some new functions dcc_tx_busy() and dcc_rx_busy() or something. Then these loops stay the same.
+
+static int hvc_dcc_get_chars_v6(uint32_t vt, char *buf, int count)
+{
+ int i;
+
+ for (i = 0; i < count; ++i)
+ if (__dcc_getstatus_v6() & DCC_STATUS_RX_V6)
+ buf[i] = __dcc_getchar_v6();
+ else
+ break;
+
+ return i;
+}
+
+static const struct hv_ops hvc_dcc_get_put_ops_v6 = {
+ .get_chars = hvc_dcc_get_chars_v6,
+ .put_chars = hvc_dcc_put_chars_v6,
+};
+
+#define DCC_STATUS_RX (1 << 0)
+#define DCC_STATUS_TX (1 << 1)
+
+/* primitive JTAG1 protocol utilities */This comment doesn't tell me much. Remove it?
+static inline u32 __dcc_getstatus(void)
+{
+ u32 ret;
+
+ asm __volatile__ ("mrc p14, 0, %0, c0, c0 @ read comms ctrl reg"
+ : "=r" (ret));Can you use volatile instead of __volatile__ so that the file is consistent?
+
+ return ret;
+}
+
+static inline char __dcc_getchar(void)
+{
+ char c;
+
+ asm __volatile__ ("mrc p14, 0, %0, c1, c0 @ read comms data reg"
+ : "=r" (c));
+Do you see any multiple character inputs? I think you may need an isb here similar to the v6/7 code and in the putchar as well.
+ return c;
+}
+
+static inline void __dcc_putchar(unsigned char c)
+{
+ asm __volatile__ ("mcr p14, 0, %0, c1, c0 @ write a char"
+ : /* no output register */
+ : "r" (c));
+}
+
static int hvc_dcc_put_chars(uint32_t vt, const char *buf, int count)
{
int i;-- Sent by an employee of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.