Hi Laurent,
On Tue, Dec 06, 2016 at 01:59:56AM +0200, Laurent Pinchart wrote:
> Hi Ladislav,
[snip]
> I've tested both versions with gcc 4.7.3 [1] and 4.8.5 [2]. With 4.7.3 my
> version is 4 bytes longer, and with 4.8.5 it's 4 bytes shorter. Interestingly
> enough the "break + test after loop" pattern doesn't make a difference, it's
> only the intermediate variable that results in changes to the generated code.
Interesting exercise... I hereby present 92 bytes shorter version using
gcc version 5.4.0 (OSELAS.Toolchain-2016.06.0)
I hope it's still easily readable.
> [1] arm-linux-gnueabihf-gcc (crosstool-NG
> linaro-1.13.1-4.7-2013.02-01-20130221 - Linaro GCC 2013.02) 4.7.3 20130205
> (prerelease)
>
> [2] arm-buildroot-linux-uclibcgnueabihf-gcc.br_real (Buildroot 2016.08-dirty)
> 4.8.5
Best regards,
ladis
diff --git a/drivers/clk/ti/dpll3xxx.c b/drivers/clk/ti/dpll3xxx.c
index 88f2ce8..f7772fc 100644
--- a/drivers/clk/ti/dpll3xxx.c
+++ b/drivers/clk/ti/dpll3xxx.c
@@ -838,3 +838,69 @@ int omap3_dpll4_set_rate_and_parent(struct clk_hw *hw, unsigned long rate,
return omap3_noncore_dpll_set_rate_and_parent(hw, rate, parent_rate,
index);
}
+
+/* Apply DM3730 errata sprz319 advisory 2.1. */
+static bool omap3_dpll5_apply_errata(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct omap3_dpll5_settings {
+ unsigned int rate;
+ unsigned short m, n;
+ };
+
+ int i;
+ struct dpll_data *dd;
+ struct clk_hw_omap *clk;
+ const struct omap3_dpll5_settings *p;
+ static const struct omap3_dpll5_settings precomputed[] = {
+ /*
+ * From DM3730 errata advisory 2.1, table 35 and 36.
+ * The N value is increased by 1 compared to the tables as the
+ * errata lists register values while last_rounded_field is the
+ * real divider value.
+ */
+ { 12000000, 80, 0 + 1 },
+ { 13000000, 443, 5 + 1 },
+ { 19200000, 50, 0 + 1 },
+ { 26000000, 443, 11 + 1 },
+ { 38400000, 25, 0 + 1 }
+ };
+
+ for (i = 0; i< ARRAY_SIZE(precomputed); i++) {
+ p = precomputed + i;
+ if (parent_rate == p->rate) {
+ clk = to_clk_hw_omap(hw);
+ dd = clk->dpll_data;
+ /* Update the M, N and rounded rate values */
+ dd->last_rounded_m = p->m;
+ dd->last_rounded_n = p->n;
+ dd->last_rounded_rate =
+ div_u64((u64)parent_rate * p->m, p->n);
+ omap3_noncore_dpll_program(clk, 0);
+
+ return true;
+ }
+ }
+
+ return false;
+}
+
+/**
+ * omap3_dpll5_set_rate - set rate for omap3 dpll5
+ * @hw: clock to change
+ * @rate: target rate for clock
+ * @parent_rate: rate of the parent clock
+ *
+ * Set rate for the DPLL5 clock. Apply the sprz319 advisory 2.1 on OMAP36xx if
+ * the DPLL is used for USB host (detected through the requested rate).
+ */
+int omap3_dpll5_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ if (rate == OMAP3_DPLL5_FREQ_FOR_USBHOST * 8) {
+ if (omap3_dpll5_apply_errata(hw, parent_rate))
+ return 0;
+ }
+
+ return omap3_noncore_dpll_set_rate(hw, rate, parent_rate);
+}
--
2.1.4
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
