On 02/28/2013 12:05 AM, Philip, Avinash wrote: > On Tue, Feb 26, 2013 at 23:00:31, Hunter, Jon wrote: >> The GPMC has various different configuration options such as bus-width, >> synchronous or asychronous mode selection, burst mode options etc. >> Currently, there is no common function for configuring these options and >> various devices set these options by either programming the GPMC CONFIG1 >> register directly or by calling gpmc_cs_configure() to set some of the >> options. >> >> Add a new function for configuring all of the GPMC options. Having a common >> function for configuring this options will simplify code and ease the >> migration to device-tree. >> >> Signed-off-by: Jon Hunter <[email protected]> >> --- >> arch/arm/mach-omap2/gpmc.c | 65 >> ++++++++++++++++++++++++++++++++++++++++++++ >> arch/arm/mach-omap2/gpmc.h | 6 ++++ >> 2 files changed, 71 insertions(+) >> >> diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c >> index 465cac9..fb8dfd2 100644 >> --- a/arch/arm/mach-omap2/gpmc.c >> +++ b/arch/arm/mach-omap2/gpmc.c >> @@ -1137,6 +1137,71 @@ int gpmc_calc_timings(struct gpmc_timings *gpmc_t, >> return 0; >> } >> >> +int gpmc_cs_program_settings(int cs, struct gpmc_settings *p) >> +{ >> + u32 config1; >> + >> + if ((!p->device_width) || (p->device_width > GPMC_DEVWIDTH_16BIT)) { >> + pr_err("%s: invalid width %d!", __func__, p->device_width); >> + return -EINVAL; >> + } >> + >> + /* Address-data multiplexing not supported for NAND devices */ >> + if (p->device_nand && p->mux_add_data) { >> + pr_err("%s: invalid configuration!\n", __func__); >> + return -EINVAL; >> + } >> + >> + /* Page/burst mode supports lengths of 4, 8 and 16 bytes */ >> + if (p->burst_read || p->burst_write) { >> + switch (p->burst_len) { >> + case GPMC_BURST_4: >> + case GPMC_BURST_8: >> + case GPMC_BURST_16: >> + break; >> + default: >> + pr_err("%s: invalid page/burst-length (%d)\n", >> + __func__, p->burst_len); >> + return -EINVAL; >> + } >> + } >> + >> + if ((p->wait_on_read || p->wait_on_write) && >> + (p->wait_pin > gpmc_nr_waitpins)) { >> + pr_err("%s: invalid wait-pin (%d)\n", __func__, p->wait_pin); >> + return -EINVAL; >> + } >> + >> + config1 = GPMC_CONFIG1_DEVICESIZE((p->device_width - 1)); > > Can you consider read_modify approach?
I was purposely trying to avoid that. The intent here is to program all the settings and get away from any boot-loader dependencies. If we use a read-modify approach then it will never be clear in the kernel what should actually be programmed. Cheers Jon _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
