--- /dev/null
+:orphan:
+
+========================================
+GPMC (General Purpose Memory Controller)
+========================================
+
+GPMC is an unified memory controller dedicated to interfacing external
+memory devices like
+
+ * Asynchronous SRAM like memories and application specific integrated
+ circuit devices.
+ * Asynchronous, synchronous, and page mode burst NOR flash devices
+ NAND flash
+ * Pseudo-SRAM devices
+
+GPMC is found on Texas Instruments SoC's (OMAP based)
+IP details: http://www.ti.com/lit/pdf/spruh73 section 7.1
+
+
+GPMC generic timing calculation:
+================================
+
+GPMC has certain timings that has to be programmed for proper
+functioning of the peripheral, while peripheral has another set of
+timings. To have peripheral work with gpmc, peripheral timings has to
+be translated to the form gpmc can understand. The way it has to be
+translated depends on the connected peripheral. Also there is a
+dependency for certain gpmc timings on gpmc clock frequency. Hence a
+generic timing routine was developed to achieve above requirements.
+
+Generic routine provides a generic method to calculate gpmc timings
+from gpmc peripheral timings. struct gpmc_device_timings fields has to
+be updated with timings from the datasheet of the peripheral that is
+connected to gpmc. A few of the peripheral timings can be fed either
+in time or in cycles, provision to handle this scenario has been
+provided (refer struct gpmc_device_timings definition). It may so
+happen that timing as specified by peripheral datasheet is not present
+in timing structure, in this scenario, try to correlate peripheral
+timing to the one available. If that doesn't work, try to add a new
+field as required by peripheral, educate generic timing routine to
+handle it, make sure that it does not break any of the existing.
+Then there may be cases where peripheral datasheet doesn't mention
+certain fields of struct gpmc_device_timings, zero those entries.
+
+Generic timing routine has been verified to work properly on
+multiple onenand's and tusb6010 peripherals.
+
+A word of caution: generic timing routine has been developed based
+on understanding of gpmc timings, peripheral timings, available
+custom timing routines, a kind of reverse engineering without
+most of the datasheets & hardware (to be exact none of those supported
+in mainline having custom timing routine) and by simulation.
+
+gpmc timing dependency on peripheral timings:
+
+[<gpmc_timing>: <peripheral timing1>, <peripheral timing2> ...]
+
+1. common
+
+cs_on:
+ t_ceasu
+adv_on:
+ t_avdasu, t_ceavd
+
+2. sync common
+
+sync_clk:
+ clk
+page_burst_access:
+ t_bacc
+clk_activation:
+ t_ces, t_avds
+
+3. read async muxed
+
+adv_rd_off:
+ t_avdp_r
+oe_on:
+ t_oeasu, t_aavdh
+access:
+ t_iaa, t_oe, t_ce, t_aa
+rd_cycle:
+ t_rd_cycle, t_cez_r, t_oez
+
+4. read async non-muxed
+
+adv_rd_off:
+ t_avdp_r
+oe_on:
+ t_oeasu
+access:
+ t_iaa, t_oe, t_ce, t_aa
+rd_cycle:
+ t_rd_cycle, t_cez_r, t_oez
+
+5. read sync muxed
+
+adv_rd_off:
+ t_avdp_r, t_avdh
+oe_on:
+ t_oeasu, t_ach, cyc_aavdh_oe
+access:
+ t_iaa, cyc_iaa, cyc_oe
+rd_cycle:
+ t_cez_r, t_oez, t_ce_rdyz
+
+6. read sync non-muxed
+
+adv_rd_off:
+ t_avdp_r
+oe_on:
+ t_oeasu
+access:
+ t_iaa, cyc_iaa, cyc_oe
+rd_cycle:
+ t_cez_r, t_oez, t_ce_rdyz
+
+7. write async muxed
+
+adv_wr_off:
+ t_avdp_w
+we_on, wr_data_mux_bus:
+ t_weasu, t_aavdh, cyc_aavhd_we
+we_off:
+ t_wpl
+cs_wr_off:
+ t_wph
+wr_cycle:
+ t_cez_w, t_wr_cycle
+
+8. write async non-muxed
+
+adv_wr_off:
+ t_avdp_w
+we_on, wr_data_mux_bus:
+ t_weasu
+we_off:
+ t_wpl
+cs_wr_off:
+ t_wph
+wr_cycle:
+ t_cez_w, t_wr_cycle
+
+9. write sync muxed
+
+adv_wr_off:
+ t_avdp_w, t_avdh
+we_on, wr_data_mux_bus:
+ t_weasu, t_rdyo, t_aavdh, cyc_aavhd_we
+we_off:
+ t_wpl, cyc_wpl
+cs_wr_off:
+ t_wph
+wr_cycle:
+ t_cez_w, t_ce_rdyz
+
+10. write sync non-muxed
+
+adv_wr_off:
+ t_avdp_w
+we_on, wr_data_mux_bus:
+ t_weasu, t_rdyo
+we_off:
+ t_wpl, cyc_wpl
+cs_wr_off:
+ t_wph
+wr_cycle:
+ t_cez_w, t_ce_rdyz
+
+
+Note:
+ Many of gpmc timings are dependent on other gpmc timings (a few
+ gpmc timings purely dependent on other gpmc timings, a reason that
+ some of the gpmc timings are missing above), and it will result in
+ indirect dependency of peripheral timings to gpmc timings other than
+ mentioned above, refer timing routine for more details. To know what
+ these peripheral timings correspond to, please see explanations in
+ struct gpmc_device_timings definition. And for gpmc timings refer
+ IP details (link above).
+++ /dev/null
-GPMC (General Purpose Memory Controller):
-=========================================
-
-GPMC is an unified memory controller dedicated to interfacing external
-memory devices like
- * Asynchronous SRAM like memories and application specific integrated
- circuit devices.
- * Asynchronous, synchronous, and page mode burst NOR flash devices
- NAND flash
- * Pseudo-SRAM devices
-
-GPMC is found on Texas Instruments SoC's (OMAP based)
-IP details: http://www.ti.com/lit/pdf/spruh73 section 7.1
-
-
-GPMC generic timing calculation:
-================================
-
-GPMC has certain timings that has to be programmed for proper
-functioning of the peripheral, while peripheral has another set of
-timings. To have peripheral work with gpmc, peripheral timings has to
-be translated to the form gpmc can understand. The way it has to be
-translated depends on the connected peripheral. Also there is a
-dependency for certain gpmc timings on gpmc clock frequency. Hence a
-generic timing routine was developed to achieve above requirements.
-
-Generic routine provides a generic method to calculate gpmc timings
-from gpmc peripheral timings. struct gpmc_device_timings fields has to
-be updated with timings from the datasheet of the peripheral that is
-connected to gpmc. A few of the peripheral timings can be fed either
-in time or in cycles, provision to handle this scenario has been
-provided (refer struct gpmc_device_timings definition). It may so
-happen that timing as specified by peripheral datasheet is not present
-in timing structure, in this scenario, try to correlate peripheral
-timing to the one available. If that doesn't work, try to add a new
-field as required by peripheral, educate generic timing routine to
-handle it, make sure that it does not break any of the existing.
-Then there may be cases where peripheral datasheet doesn't mention
-certain fields of struct gpmc_device_timings, zero those entries.
-
-Generic timing routine has been verified to work properly on
-multiple onenand's and tusb6010 peripherals.
-
-A word of caution: generic timing routine has been developed based
-on understanding of gpmc timings, peripheral timings, available
-custom timing routines, a kind of reverse engineering without
-most of the datasheets & hardware (to be exact none of those supported
-in mainline having custom timing routine) and by simulation.
-
-gpmc timing dependency on peripheral timings:
-[<gpmc_timing>: <peripheral timing1>, <peripheral timing2> ...]
-
-1. common
-cs_on: t_ceasu
-adv_on: t_avdasu, t_ceavd
-
-2. sync common
-sync_clk: clk
-page_burst_access: t_bacc
-clk_activation: t_ces, t_avds
-
-3. read async muxed
-adv_rd_off: t_avdp_r
-oe_on: t_oeasu, t_aavdh
-access: t_iaa, t_oe, t_ce, t_aa
-rd_cycle: t_rd_cycle, t_cez_r, t_oez
-
-4. read async non-muxed
-adv_rd_off: t_avdp_r
-oe_on: t_oeasu
-access: t_iaa, t_oe, t_ce, t_aa
-rd_cycle: t_rd_cycle, t_cez_r, t_oez
-
-5. read sync muxed
-adv_rd_off: t_avdp_r, t_avdh
-oe_on: t_oeasu, t_ach, cyc_aavdh_oe
-access: t_iaa, cyc_iaa, cyc_oe
-rd_cycle: t_cez_r, t_oez, t_ce_rdyz
-
-6. read sync non-muxed
-adv_rd_off: t_avdp_r
-oe_on: t_oeasu
-access: t_iaa, cyc_iaa, cyc_oe
-rd_cycle: t_cez_r, t_oez, t_ce_rdyz
-
-7. write async muxed
-adv_wr_off: t_avdp_w
-we_on, wr_data_mux_bus: t_weasu, t_aavdh, cyc_aavhd_we
-we_off: t_wpl
-cs_wr_off: t_wph
-wr_cycle: t_cez_w, t_wr_cycle
-
-8. write async non-muxed
-adv_wr_off: t_avdp_w
-we_on, wr_data_mux_bus: t_weasu
-we_off: t_wpl
-cs_wr_off: t_wph
-wr_cycle: t_cez_w, t_wr_cycle
-
-9. write sync muxed
-adv_wr_off: t_avdp_w, t_avdh
-we_on, wr_data_mux_bus: t_weasu, t_rdyo, t_aavdh, cyc_aavhd_we
-we_off: t_wpl, cyc_wpl
-cs_wr_off: t_wph
-wr_cycle: t_cez_w, t_ce_rdyz
-
-10. write sync non-muxed
-adv_wr_off: t_avdp_w
-we_on, wr_data_mux_bus: t_weasu, t_rdyo
-we_off: t_wpl, cyc_wpl
-cs_wr_off: t_wph
-wr_cycle: t_cez_w, t_ce_rdyz
-
-
-Note: Many of gpmc timings are dependent on other gpmc timings (a few
-gpmc timings purely dependent on other gpmc timings, a reason that
-some of the gpmc timings are missing above), and it will result in
-indirect dependency of peripheral timings to gpmc timings other than
-mentioned above, refer timing routine for more details. To know what
-these peripheral timings correspond to, please see explanations in
-struct gpmc_device_timings definition. And for gpmc timings refer
-IP details (link above).