Re: [PATCH 06/10] ARM: OMAP2+: Show bootloader GPMC timings to allow configuring the .dts file

[Tony Lindgren <tony@atomide.com>]

* Roger Quadros <rogerq@ti.com> [141030 08:05]:
> On 10/30/2014 04:45 PM, Tony Lindgren wrote:
> > * Roger Quadros <rogerq@ti.com> [141030 07:21]:
> >> On 10/30/2014 02:29 AM, Tony Lindgren wrote:
> >>> +static void gpmc_cs_show_timings(int cs, const char *desc)
> >>> +{
> >>> +	gpmc_show_regs(cs, desc);
> >>> +
> >>> +	pr_info("gpmc cs%i access configuration:\n", cs);
> >>> +	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1,  4,  4, "time-para-granularity");
> >>> +	GPMC_GET_RAW(GPMC_CS_CONFIG1,  8,  9, "mux-add-data");
> >>> +	GPMC_GET_RAW(GPMC_CS_CONFIG1, 12, 13, "device-width");
> >>> +	GPMC_GET_RAW(GPMC_CS_CONFIG1, 16, 17, "wait-pin");
> >>> +	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 21, 21, "wait-on-write");
> >>> +	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 22, 22, "wait-on-read");
> >>> +	GPMC_GET_RAW_SHIFT(GPMC_CS_CONFIG1, 23, 24, 3, "burst-length");
> >>
> >> how does this work with shift = 3?
> >> Possible values of burst length are
> >> 0 -> 4
> >> 1 -> 8
> >> 2 -> 16
> > 
> > Hmm sounds like a bug..

The shift does not work here for 0 << 3 naturally :) I've changed
it to l = (shift << l) where shift is 4 in this case.
 
> > In general, if you a chance to test this patch with a few
> > devices that would be great. Assuming you have working timings
> > in the bootloader, just remove the gpmc,* entries temporarily
> > from the .dts file for a device, and see if the values printed
> > by this patch make sense. I've used this to generate the values
> > for the 2430sdp smc91x and zoom 8250 but I don't think I've tried
> > anything with a burst mode so far.
> 
> OK. I'll give it a spin with u-boot configured devices.

Great thanks. Updated patch below.

Regards,

Tony


8< ----------------
From: Tony Lindgren <tony@atomide.com>
Date: Wed, 29 Oct 2014 17:16:48 -0700
Subject: [PATCH] ARM: OMAP2+: Show bootloader GPMC timings to allow configuring the .dts file

As we still have some devices with GPMC timings missing from the
.dts files, let's make it a bit easier to use the bootloader
values and print them out.

Note that we now need to move the parsing of the device tree provided
configuration a bit earlier so we can use that for checking if anything
was configured.

Cc: Roger Quadros <rogerq@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

--- a/arch/arm/mach-omap2/gpmc.c
+++ b/arch/arm/mach-omap2/gpmc.c
@@ -292,6 +292,129 @@ static void gpmc_cs_bool_timings(int cs, const struct gpmc_bool_timings *p)
 }
 
 #ifdef DEBUG
+static int get_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit,
+			       bool raw, bool noval, int shift,
+			       const char *name)
+{
+	u32 l;
+	int nr_bits, max_value, mask;
+
+	l = gpmc_cs_read_reg(cs, reg);
+	nr_bits = end_bit - st_bit + 1;
+	max_value = (1 << nr_bits) - 1;
+	mask = max_value << st_bit;
+	l = (l & mask) >> st_bit;
+	if (shift)
+		l = (shift << l);
+	if (noval && (l == 0))
+		return 0;
+	if (!raw) {
+		unsigned int time_ns_min, time_ns, time_ns_max;
+
+		time_ns_min = gpmc_ticks_to_ns(l ? l - 1 : 0);
+		time_ns = gpmc_ticks_to_ns(l);
+		time_ns_max = gpmc_ticks_to_ns(l + 1 > max_value ?
+					       max_value : l + 1);
+		pr_info("gpmc,%s = <%u> (%u - %u ns, %i ticks)\n",
+			name, time_ns, time_ns_min, time_ns_max, l);
+	} else {
+		pr_info("gpmc,%s = <%u>\n", name, l);
+	}
+
+	return l;
+}
+
+#define GPMC_PRINT_CONFIG(cs, config) \
+	pr_info("cs%i %s: 0x%08x\n", cs, #config, \
+		gpmc_cs_read_reg(cs, config))
+#define GPMC_GET_RAW(reg, st, end, field) \
+	get_gpmc_timing_reg(cs, (reg), (st), (end), 1, 0, 0, field)
+#define GPMC_GET_RAW_BOOL(reg, st, end, field) \
+	get_gpmc_timing_reg(cs, (reg), (st), (end), 1, 1, 0, field)
+#define GPMC_GET_RAW_SHIFT(reg, st, end, shift, field) \
+	get_gpmc_timing_reg(cs, (reg), (st), (end), 1, 1, (shift), field)
+#define GPMC_GET_TICKS(reg, st, end, field) \
+	get_gpmc_timing_reg(cs, (reg), (st), (end), 0, 0, 0, field)
+
+static void gpmc_show_regs(int cs, const char *desc)
+{
+	pr_info("gpmc cs%i %s:\n", cs, desc);
+	GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG1);
+	GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG2);
+	GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG3);
+	GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG4);
+	GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG5);
+	GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG6);
+}
+
+/*
+ * Note that gpmc,wait-pin handing wrongly assumes bit 8 is available,
+ * see commit c9fb809.
+ */
+static void gpmc_cs_show_timings(int cs, const char *desc)
+{
+	gpmc_show_regs(cs, desc);
+
+	pr_info("gpmc cs%i access configuration:\n", cs);
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1,  4,  4, "time-para-granularity");
+	GPMC_GET_RAW(GPMC_CS_CONFIG1,  8,  9, "mux-add-data");
+	GPMC_GET_RAW(GPMC_CS_CONFIG1, 12, 13, "device-width");
+	GPMC_GET_RAW(GPMC_CS_CONFIG1, 16, 17, "wait-pin");
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 21, 21, "wait-on-write");
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 22, 22, "wait-on-read");
+	GPMC_GET_RAW_SHIFT(GPMC_CS_CONFIG1, 23, 24, 4, "burst-length");
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 27, 27, "sync-write");
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 28, 28, "burst-write");
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 29, 29, "gpmc,sync-read");
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 30, 30, "burst-read");
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 31, 31, "burst-wrap");
+
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG2,  7,  7, "cs-extra-delay");
+
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG3,  7,  7, "adv-extra-delay");
+
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG4, 23, 23, "we-extra-delay");
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG4,  7,  7, "oe-extra-delay");
+
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG6,  7,  7, "cycle2cycle-samecsen");
+	GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG6,  6,  6, "cycle2cycle-diffcsen");
+
+	pr_info("gpmc cs%i timings configuration:\n", cs);
+	GPMC_GET_TICKS(GPMC_CS_CONFIG2,  0,  3, "cs-on-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG2,  8, 12, "cs-rd-off-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG2, 16, 20, "cs-wr-off-ns");
+
+	GPMC_GET_TICKS(GPMC_CS_CONFIG3,  0,  3, "adv-on-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG3,  8, 12, "adv-rd-off-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG3, 16, 20, "adv-wr-off-ns");
+
+	GPMC_GET_TICKS(GPMC_CS_CONFIG4,  0,  3, "oe-on-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG4,  8, 12, "oe-off-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG4, 16, 19, "we-on-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG4, 24, 28, "we-off-ns");
+
+	GPMC_GET_TICKS(GPMC_CS_CONFIG5,  0,  4, "rd-cycle-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG5,  8, 12, "wr-cycle-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG5, 16, 20, "access-ns");
+
+	GPMC_GET_TICKS(GPMC_CS_CONFIG5, 24, 27, "page-burst-access-ns");
+
+	GPMC_GET_TICKS(GPMC_CS_CONFIG6, 0, 3, "bus-turnaround-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG6, 8, 11, "cycle2cycle-delay-ns");
+
+	GPMC_GET_TICKS(GPMC_CS_CONFIG1, 18, 19, "wait-monitoring-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG1, 25, 26, "clk-activation-ns");
+
+	GPMC_GET_TICKS(GPMC_CS_CONFIG6, 16, 19, "wr-data-mux-bus-ns");
+	GPMC_GET_TICKS(GPMC_CS_CONFIG6, 24, 28, "wr-access-ns");
+}
+#else
+static inline void gpmc_cs_show_timings(int cs, const char *desc)
+{
+}
+#endif
+
+#ifdef DEBUG
 static int set_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit,
 			       int time, const char *name)
 #else
@@ -361,6 +484,7 @@ int gpmc_cs_set_timings(int cs, const struct gpmc_timings *t)
 	int div;
 	u32 l;
 
+	gpmc_cs_show_timings(cs, "before gpmc_cs_set_timings");
 	div = gpmc_calc_divider(t->sync_clk);
 	if (div < 0)
 		return div;
@@ -410,6 +534,7 @@ int gpmc_cs_set_timings(int cs, const struct gpmc_timings *t)
 	}
 
 	gpmc_cs_bool_timings(cs, &t->bool_timings);
+	gpmc_cs_show_timings(cs, "after gpmc_cs_set_timings");
 
 	return 0;
 }
@@ -1571,6 +1696,22 @@ static int gpmc_probe_generic_child(struct platform_device *pdev,
 	}
 	gpmc_cs_set_name(cs, child->name);
 
+	gpmc_read_settings_dt(child, &gpmc_s);
+	gpmc_read_timings_dt(child, &gpmc_t);
+
+	/*
+	 * For some GPMC devices we still need to rely on the bootloader
+	 * timings because the devices can be connected via FPGA.
+	 * REVISIT: Add timing support from slls644g.pdf.
+	 */
+	if (!gpmc_t.cs_rd_off) {
+		WARN(1, "enable GPMC debug to configure .dts timings for CS%i\n",
+			cs);
+		gpmc_cs_show_timings(cs,
+				     "please add GPMC bootloader timings to .dts");
+		goto no_timings;
+	}
+
 	/*
 	 * For some GPMC devices we still need to rely on the bootloader
 	 * timings because the devices can be connected via FPGA. So far
@@ -1602,8 +1743,6 @@ static int gpmc_probe_generic_child(struct platform_device *pdev,
 		goto err;
 	}
 
-	gpmc_read_settings_dt(child, &gpmc_s);
-
 	ret = of_property_read_u32(child, "bank-width", &gpmc_s.device_width);
 	if (ret < 0)
 		goto err;
@@ -1612,7 +1751,6 @@ static int gpmc_probe_generic_child(struct platform_device *pdev,
 	if (ret < 0)
 		goto err;
 
-	gpmc_read_timings_dt(child, &gpmc_t);
 	gpmc_cs_set_timings(cs, &gpmc_t);
 
 no_timings: