diff options
author | Paul Walmsley <paul@pwsan.com> | 2010-01-08 17:23:15 -0500 |
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committer | Paul Walmsley <paul@pwsan.com> | 2010-01-08 17:23:15 -0500 |
commit | ca6eccb31ef63722b35ea695f75089adeec319d7 (patch) | |
tree | c88b9a6500b855343fa9b62429e1182c311d3fd7 /arch/arm/mach-omap2/opp2420_data.c | |
parent | 19fe458310915a216bbba32a210b6f29ac7c929f (diff) |
OMAP2xxx OPP: clean up comments in OPP data
Revise some of the comments in the OMAP2xxx OPP data for clarity.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Richard Woodruff <r-woodruff2@ti.com>
Diffstat (limited to 'arch/arm/mach-omap2/opp2420_data.c')
-rw-r--r-- | arch/arm/mach-omap2/opp2420_data.c | 38 |
1 files changed, 20 insertions, 18 deletions
diff --git a/arch/arm/mach-omap2/opp2420_data.c b/arch/arm/mach-omap2/opp2420_data.c index 126a9396b3a8..e6dda694fd5c 100644 --- a/arch/arm/mach-omap2/opp2420_data.c +++ b/arch/arm/mach-omap2/opp2420_data.c | |||
@@ -9,45 +9,47 @@ | |||
9 | * The OMAP2 processor can be run at several discrete 'PRCM configurations'. | 9 | * The OMAP2 processor can be run at several discrete 'PRCM configurations'. |
10 | * These configurations are characterized by voltage and speed for clocks. | 10 | * These configurations are characterized by voltage and speed for clocks. |
11 | * The device is only validated for certain combinations. One way to express | 11 | * The device is only validated for certain combinations. One way to express |
12 | * these combinations is via the 'ratio's' which the clocks operate with | 12 | * these combinations is via the 'ratios' which the clocks operate with |
13 | * respect to each other. These ratio sets are for a given voltage/DPLL | 13 | * respect to each other. These ratio sets are for a given voltage/DPLL |
14 | * setting. All configurations can be described by a DPLL setting and a ratio | 14 | * setting. All configurations can be described by a DPLL setting and a ratio. |
15 | * There are 3 ratio sets for the 2430 and X ratio sets for 2420. | ||
16 | * | ||
17 | * 2430 differs from 2420 in that there are no more phase synchronizers used. | ||
18 | * They both have a slightly different clock domain setup. 2420(iva1,dsp) vs | ||
19 | * 2430 (iva2.1, NOdsp, mdm) | ||
20 | * | 15 | * |
21 | * XXX Missing voltage data. | 16 | * XXX Missing voltage data. |
17 | * XXX Missing 19.2MHz sys_clk rate sets (needed for N800/N810) | ||
22 | * | 18 | * |
23 | * THe format described in this file is deprecated. Once a reasonable | 19 | * THe format described in this file is deprecated. Once a reasonable |
24 | * OPP API exists, the data in this file should be converted to use it. | 20 | * OPP API exists, the data in this file should be converted to use it. |
25 | * | 21 | * |
26 | * This is technically part of the OMAP2xxx clock code. | 22 | * This is technically part of the OMAP2xxx clock code. |
23 | * | ||
24 | * Considerable work is still needed to fully support dynamic frequency | ||
25 | * changes on OMAP2xxx-series chips. Readers interested in such a | ||
26 | * project are encouraged to review the Maemo Diablo RX-34 and RX-44 | ||
27 | * kernel source at: | ||
28 | * http://repository.maemo.org/pool/diablo/free/k/kernel-source-diablo/ | ||
27 | */ | 29 | */ |
28 | 30 | ||
29 | #include "opp2xxx.h" | 31 | #include "opp2xxx.h" |
30 | #include "sdrc.h" | 32 | #include "sdrc.h" |
31 | #include "clock.h" | 33 | #include "clock.h" |
32 | 34 | ||
33 | /*------------------------------------------------------------------------- | 35 | /* |
34 | * Key dividers which make up a PRCM set. Ratio's for a PRCM are mandated. | 36 | * Key dividers which make up a PRCM set. Ratios for a PRCM are mandated. |
35 | * xtal_speed, dpll_speed, mpu_speed, CM_CLKSEL_MPU, | 37 | * xtal_speed, dpll_speed, mpu_speed, CM_CLKSEL_MPU, |
36 | * CM_CLKSEL_DSP, CM_CLKSEL_GFX, CM_CLKSEL1_CORE, CM_CLKSEL1_PLL, | 38 | * CM_CLKSEL_DSP, CM_CLKSEL_GFX, CM_CLKSEL1_CORE, CM_CLKSEL1_PLL, |
37 | * CM_CLKSEL2_PLL, CM_CLKSEL_MDM | 39 | * CM_CLKSEL2_PLL, CM_CLKSEL_MDM |
38 | * | 40 | * |
39 | * Filling in table based on H4 boards and 2430-SDPs variants available. | 41 | * Filling in table based on H4 boards available. There are quite a |
40 | * There are quite a few more rates combinations which could be defined. | 42 | * few more rate combinations which could be defined. |
41 | * | 43 | * |
42 | * When multiple values are defined the start up will try and choose the | 44 | * When multiple values are defined the start up will try and choose |
43 | * fastest one. If a 'fast' value is defined, then automatically, the /2 | 45 | * the fastest one. If a 'fast' value is defined, then automatically, |
44 | * one should be included as it can be used. Generally having more that | 46 | * the /2 one should be included as it can be used. Generally having |
45 | * one fast set does not make sense, as static timings need to be changed | 47 | * more than one fast set does not make sense, as static timings need |
46 | * to change the set. The exception is the bypass setting which is | 48 | * to be changed to change the set. The exception is the bypass |
47 | * availble for low power bypass. | 49 | * setting which is available for low power bypass. |
48 | * | 50 | * |
49 | * Note: This table needs to be sorted, fastest to slowest. | 51 | * Note: This table needs to be sorted, fastest to slowest. |
50 | *-------------------------------------------------------------------------*/ | 52 | **/ |
51 | const struct prcm_config omap2420_rate_table[] = { | 53 | const struct prcm_config omap2420_rate_table[] = { |
52 | /* PRCM I - FAST */ | 54 | /* PRCM I - FAST */ |
53 | {S12M, S660M, S330M, RI_CM_CLKSEL_MPU_VAL, /* 330MHz ARM */ | 55 | {S12M, S660M, S330M, RI_CM_CLKSEL_MPU_VAL, /* 330MHz ARM */ |