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authorFernando Guzman Lugo <fernando.lugo@ti.com>2012-04-13 13:08:03 +0200
committerPaul Walmsley <paul@pwsan.com>2012-04-13 13:08:03 +0200
commitd99de7f552fac43e24fd4fb8048d8f21abaea691 (patch)
tree29437f2fd6b5f8516ce1cfe773b93b7bdab9c290 /arch/arm/mach-omap2/omap_hwmod.c
parentLinux 3.4-rc2 (diff)
downloadlinux-d99de7f552fac43e24fd4fb8048d8f21abaea691.tar.xz
linux-d99de7f552fac43e24fd4fb8048d8f21abaea691.zip
ARM: OMAP2+: hwmod: add softreset delay field and OMAP4 data
Due to HW limitation, some IPs should not be accessed just after a softreset. Since the current hwmod sequence is accessing the sysconfig register just after the reset, it might lead to OCP bus error in that case. Add a new field in the sysconfig structure to specify a delay in usecs needed after doing a softreset. In the case of the ISS and FDIF modules, the L3 OCP port will be disconnected upon a SW reset. That issue was confirmed with HW simulation and an errata should be available soon. The HW recommendation to avoid that is to wait for 100 OCP clk cycles, before accessing the IP. Considering the worse case (OPP50), the L3 bus will run at 100 MHz, so a 1 usec delay is needed. Add an x2 margin to be safe. Acked-by: Benoit Cousson <b-cousson@ti.com> Signed-off-by: Fernando Guzman Lugo <fernando.lugo@ti.com> [paul@pwsan.com: dropped FDIF change for now since the hwmod data is not yet upstream; the FDIF change will need to be added later once the FDIF data is merged] Signed-off-by: Paul Walmsley <paul@pwsan.com>
Diffstat (limited to 'arch/arm/mach-omap2/omap_hwmod.c')
-rw-r--r--arch/arm/mach-omap2/omap_hwmod.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index 2c27fdb61e66..45f1d9c44e94 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -1422,6 +1422,9 @@ static int _ocp_softreset(struct omap_hwmod *oh)
goto dis_opt_clks;
_write_sysconfig(v, oh);
+ if (oh->class->sysc->srst_udelay)
+ udelay(oh->class->sysc->srst_udelay);
+
if (oh->class->sysc->sysc_flags & SYSS_HAS_RESET_STATUS)
omap_test_timeout((omap_hwmod_read(oh,
oh->class->sysc->syss_offs)