diff options
| -rw-r--r-- | Documentation/bus-devices/ti-gpmc.txt | 122 | ||||
| -rw-r--r-- | arch/arm/mach-omap2/gpmc.c | 325 | ||||
| -rw-r--r-- | arch/arm/mach-omap2/gpmc.h | 102 |
3 files changed, 529 insertions, 20 deletions
diff --git a/Documentation/bus-devices/ti-gpmc.txt b/Documentation/bus-devices/ti-gpmc.txt new file mode 100644 index 000000000000..cc9ce57e0a26 --- /dev/null +++ b/Documentation/bus-devices/ti-gpmc.txt @@ -0,0 +1,122 @@ +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). diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c index 5619d1b48668..65468f6d7f0e 100644 --- a/arch/arm/mach-omap2/gpmc.c +++ b/arch/arm/mach-omap2/gpmc.c @@ -230,6 +230,18 @@ unsigned int gpmc_round_ns_to_ticks(unsigned int time_ns) return ticks * gpmc_get_fclk_period() / 1000; } +static unsigned int gpmc_ticks_to_ps(unsigned int ticks) +{ + return ticks * gpmc_get_fclk_period(); +} + +static unsigned int gpmc_round_ps_to_ticks(unsigned int time_ps) +{ + unsigned long ticks = gpmc_ps_to_ticks(time_ps); + + return ticks * gpmc_get_fclk_period(); +} + static inline void gpmc_cs_modify_reg(int cs, int reg, u32 mask, bool value) { u32 l; @@ -796,6 +808,319 @@ static int __devinit gpmc_mem_init(void) return 0; } +static u32 gpmc_round_ps_to_sync_clk(u32 time_ps, u32 sync_clk) +{ + u32 temp; + int div; + + div = gpmc_calc_divider(sync_clk); + temp = gpmc_ps_to_ticks(time_ps); + temp = (temp + div - 1) / div; + return gpmc_ticks_to_ps(temp * div); +} + +/* XXX: can the cycles be avoided ? */ +static int gpmc_calc_sync_read_timings(struct gpmc_timings *gpmc_t, + struct gpmc_device_timings *dev_t) +{ + bool mux = dev_t->mux; + u32 temp; + + /* adv_rd_off */ + temp = dev_t->t_avdp_r; + /* XXX: mux check required ? */ + if (mux) { + /* XXX: t_avdp not to be required for sync, only added for tusb + * this indirectly necessitates requirement of t_avdp_r and + * t_avdp_w instead of having a single t_avdp + */ + temp = max_t(u32, temp, gpmc_t->clk_activation + dev_t->t_avdh); + temp = max_t(u32, gpmc_t->adv_on + gpmc_ticks_to_ps(1), temp); + } + gpmc_t->adv_rd_off = gpmc_round_ps_to_ticks(temp); + + /* oe_on */ + temp = dev_t->t_oeasu; /* XXX: remove this ? */ + if (mux) { + temp = max_t(u32, temp, gpmc_t->clk_activation + dev_t->t_ach); + temp = max_t(u32, temp, gpmc_t->adv_rd_off + + gpmc_ticks_to_ps(dev_t->cyc_aavdh_oe)); + } + gpmc_t->oe_on = gpmc_round_ps_to_ticks(temp); + + /* access */ + /* XXX: any scope for improvement ?, by combining oe_on + * and clk_activation, need to check whether + * access = clk_activation + round to sync clk ? + */ + temp = max_t(u32, dev_t->t_iaa, dev_t->cyc_iaa * gpmc_t->sync_clk); + temp += gpmc_t->clk_activation; + if (dev_t->cyc_oe) + temp = max_t(u32, temp, gpmc_t->oe_on + + gpmc_ticks_to_ps(dev_t->cyc_oe)); + gpmc_t->access = gpmc_round_ps_to_ticks(temp); + + gpmc_t->oe_off = gpmc_t->access + gpmc_ticks_to_ps(1); + gpmc_t->cs_rd_off = gpmc_t->oe_off; + + /* rd_cycle */ + temp = max_t(u32, dev_t->t_cez_r, dev_t->t_oez); + temp = gpmc_round_ps_to_sync_clk(temp, gpmc_t->sync_clk) + + gpmc_t->access; + /* XXX: barter t_ce_rdyz with t_cez_r ? */ + if (dev_t->t_ce_rdyz) + temp = max_t(u32, temp, gpmc_t->cs_rd_off + dev_t->t_ce_rdyz); + gpmc_t->rd_cycle = gpmc_round_ps_to_ticks(temp); + + return 0; +} + +static int gpmc_calc_sync_write_timings(struct gpmc_timings *gpmc_t, + struct gpmc_device_timings *dev_t) +{ + bool mux = dev_t->mux; + u32 temp; + + /* adv_wr_off */ + temp = dev_t->t_avdp_w; + if (mux) { + temp = max_t(u32, temp, + gpmc_t->clk_activation + dev_t->t_avdh); + temp = max_t(u32, gpmc_t->adv_on + gpmc_ticks_to_ps(1), temp); + } + gpmc_t->adv_wr_off = gpmc_round_ps_to_ticks(temp); + + /* wr_data_mux_bus */ + temp = max_t(u32, dev_t->t_weasu, + gpmc_t->clk_activation + dev_t->t_rdyo); + /* XXX: shouldn't mux be kept as a whole for wr_data_mux_bus ?, + * and in that case remember to handle we_on properly + */ + if (mux) { + temp = max_t(u32, temp, + gpmc_t->adv_wr_off + dev_t->t_aavdh); + temp = max_t(u32, temp, gpmc_t->adv_wr_off + + gpmc_ticks_to_ps(dev_t->cyc_aavdh_we)); + } + gpmc_t->wr_data_mux_bus = gpmc_round_ps_to_ticks(temp); + + /* we_on */ + if (gpmc_capability & GPMC_HAS_WR_DATA_MUX_BUS) + gpmc_t->we_on = gpmc_round_ps_to_ticks(dev_t->t_weasu); + else + gpmc_t->we_on = gpmc_t->wr_data_mux_bus; + + /* wr_access */ + /* XXX: gpmc_capability check reqd ? , even if not, will not harm */ + gpmc_t->wr_access = gpmc_t->access; + + /* we_off */ + temp = gpmc_t->we_on + dev_t->t_wpl; + temp = max_t(u32, temp, + gpmc_t->wr_access + gpmc_ticks_to_ps(1)); + temp = max_t(u32, temp, + gpmc_t->we_on + gpmc_ticks_to_ps(dev_t->cyc_wpl)); + gpmc_t->we_off = gpmc_round_ps_to_ticks(temp); + + gpmc_t->cs_wr_off = gpmc_round_ps_to_ticks(gpmc_t->we_off + + dev_t->t_wph); + + /* wr_cycle */ + temp = gpmc_round_ps_to_sync_clk(dev_t->t_cez_w, gpmc_t->sync_clk); + temp += gpmc_t->wr_access; + /* XXX: barter t_ce_rdyz with t_cez_w ? */ + if (dev_t->t_ce_rdyz) + temp = max_t(u32, temp, + gpmc_t->cs_wr_off + dev_t->t_ce_rdyz); + gpmc_t->wr_cycle = gpmc_round_ps_to_ticks(temp); + + return 0; +} + +static int gpmc_calc_async_read_timings(struct gpmc_timings *gpmc_t, + struct gpmc_device_timings *dev_t) +{ + bool mux = dev_t->mux; + u32 temp; + + /* adv_rd_off */ + temp = dev_t->t_avdp_r; + if (mux) + temp = max_t(u32, gpmc_t->adv_on + gpmc_ticks_to_ps(1), temp); + gpmc_t->adv_rd_off = gpmc_round_ps_to_ticks(temp); + + /* oe_on */ + temp = dev_t->t_oeasu; + if (mux) + temp = max_t(u32, temp, + gpmc_t->adv_rd_off + dev_t->t_aavdh); + gpmc_t->oe_on = gpmc_round_ps_to_ticks(temp); + + /* access */ + temp = max_t(u32, dev_t->t_iaa, /* XXX: remove t_iaa in async ? */ + gpmc_t->oe_on + dev_t->t_oe); + temp = max_t(u32, temp, + gpmc_t->cs_on + dev_t->t_ce); + temp = max_t(u32, temp, + gpmc_t->adv_on + dev_t->t_aa); + gpmc_t->access = gpmc_round_ps_to_ticks(temp); + + gpmc_t->oe_off = gpmc_t->access + gpmc_ticks_to_ps(1); + gpmc_t->cs_rd_off = gpmc_t->oe_off; + + /* rd_cycle */ + temp = max_t(u32, dev_t->t_rd_cycle, + gpmc_t->cs_rd_off + dev_t->t_cez_r); + temp = max_t(u32, temp, gpmc_t->oe_off + dev_t->t_oez); + gpmc_t->rd_cycle = gpmc_round_ps_to_ticks(temp); + + return 0; +} + +static int gpmc_calc_async_write_timings(struct gpmc_timings *gpmc_t, + struct gpmc_device_timings *dev_t) +{ + bool mux = dev_t->mux; + u32 temp; + + /* adv_wr_off */ + temp = dev_t->t_avdp_w; + if (mux) + temp = max_t(u32, gpmc_t->adv_on + gpmc_ticks_to_ps(1), temp); + gpmc_t->adv_wr_off = gpmc_round_ps_to_ticks(temp); + + /* wr_data_mux_bus */ + temp = dev_t->t_weasu; + if (mux) { + temp = max_t(u32, temp, gpmc_t->adv_wr_off + dev_t->t_aavdh); + temp = max_t(u32, temp, gpmc_t->adv_wr_off + + gpmc_ticks_to_ps(dev_t->cyc_aavdh_we)); + } + gpmc_t->wr_data_mux_bus = gpmc_round_ps_to_ticks(temp); + + /* we_on */ + if (gpmc_capability & GPMC_HAS_WR_DATA_MUX_BUS) + gpmc_t->we_on = gpmc_round_ps_to_ticks(dev_t->t_weasu); + else + gpmc_t->we_on = gpmc_t->wr_data_mux_bus; + + /* we_off */ + temp = gpmc_t->we_on + dev_t->t_wpl; + gpmc_t->we_off = gpmc_round_ps_to_ticks(temp); + + gpmc_t->cs_wr_off = gpmc_round_ps_to_ticks(gpmc_t->we_off + + dev_t->t_wph); + + /* wr_cycle */ + temp = max_t(u32, dev_t->t_wr_cycle, + gpmc_t->cs_wr_off + dev_t->t_cez_w); + gpmc_t->wr_cycle = gpmc_round_ps_to_ticks(temp); + + return 0; +} + +static int gpmc_calc_sync_common_timings(struct gpmc_timings *gpmc_t, + struct gpmc_device_timings *dev_t) +{ + u32 temp; + + gpmc_t->sync_clk = gpmc_calc_divider(dev_t->clk) * + gpmc_get_fclk_period(); + + gpmc_t->page_burst_access = gpmc_round_ps_to_sync_clk( + dev_t->t_bacc, + gpmc_t->sync_clk); + + temp = max_t(u32, dev_t->t_ces, dev_t->t_avds); + gpmc_t->clk_activation = gpmc_round_ps_to_ticks(temp); + + if (gpmc_calc_divider(gpmc_t->sync_clk) != 1) + return 0; + + if (dev_t->ce_xdelay) + gpmc_t->bool_timings.cs_extra_delay = true; + if (dev_t->avd_xdelay) + gpmc_t->bool_timings.adv_extra_delay = true; + if (dev_t->oe_xdelay) + gpmc_t->bool_timings.oe_extra_delay = true; + if (dev_t->we_xdelay) + gpmc_t->bool_timings.we_extra_delay = true; + + return 0; +} + +static int gpmc_calc_common_timings(struct gpmc_timings *gpmc_t, + struct gpmc_device_timings *dev_t) +{ + u32 temp; + + /* cs_on */ + gpmc_t->cs_on = gpmc_round_ps_to_ticks(dev_t->t_ceasu); + + /* adv_on */ + temp = dev_t->t_avdasu; + if (dev_t->t_ce_avd) + temp = max_t(u32, temp, + gpmc_t->cs_on + dev_t->t_ce_avd); + gpmc_t->adv_on = gpmc_round_ps_to_ticks(temp); + + if (dev_t->sync_write || dev_t->sync_read) + gpmc_calc_sync_common_timings(gpmc_t, dev_t); + + return 0; +} + +/* TODO: remove this function once all peripherals are confirmed to + * work with generic timing. Simultaneously gpmc_cs_set_timings() + * has to be modified to handle timings in ps instead of ns +*/ +static void gpmc_convert_ps_to_ns(struct gpmc_timings *t) +{ + t->cs_on /= 1000; + t->cs_rd_off /= 1000; + t->cs_wr_off /= 1000; + t->adv_on /= 1000; + t->adv_rd_off /= 1000; + t->adv_wr_off /= 1000; + t->we_on /= 1000; + t->we_off /= 1000; + t->oe_on /= 1000; + t->oe_off /= 1000; + t->page_burst_access /= 1000; + t->access /= 1000; + t->rd_cycle /= 1000; + t->wr_cycle /= 1000; + t->bus_turnaround /= 1000; + t->cycle2cycle_delay /= 1000; + t->wait_monitoring /= 1000; + t->clk_activation /= 1000; + t->wr_access /= 1000; + t->wr_data_mux_bus /= 1000; +} + +int gpmc_calc_timings(struct gpmc_timings *gpmc_t, + struct gpmc_device_timings *dev_t) +{ + memset(gpmc_t, 0, sizeof(*gpmc_t)); + + gpmc_calc_common_timings(gpmc_t, dev_t); + + if (dev_t->sync_read) + gpmc_calc_sync_read_timings(gpmc_t, dev_t); + else + gpmc_calc_async_read_timings(gpmc_t, dev_t); + + if (dev_t->sync_write) + gpmc_calc_sync_write_timings(gpmc_t, dev_t); + else + gpmc_calc_async_write_timings(gpmc_t, dev_t); + + /* TODO: remove, see function definition */ + gpmc_convert_ps_to_ns(gpmc_t); + + return 0; +} + static __devinit int gpmc_probe(struct platform_device *pdev) { int rc; diff --git a/arch/arm/mach-omap2/gpmc.h b/arch/arm/mach-omap2/gpmc.h index e08a51a7a76a..fe0a844d5007 100644 --- a/arch/arm/mach-omap2/gpmc.h +++ b/arch/arm/mach-omap2/gpmc.h @@ -94,42 +94,104 @@ struct gpmc_timings { u32 sync_clk; /* Chip-select signal timings corresponding to GPMC_CS_CONFIG2 */ - u16 cs_on; /* Assertion time */ - u16 cs_rd_off; /* Read deassertion time */ - u16 cs_wr_off; /* Write deassertion time */ + u32 cs_on; /* Assertion time */ + u32 cs_rd_off; /* Read deassertion time */ + u32 cs_wr_off; /* Write deassertion time */ /* ADV signal timings corresponding to GPMC_CONFIG3 */ - u16 adv_on; /* Assertion time */ - u16 adv_rd_off; /* Read deassertion time */ - u16 adv_wr_off; /* Write deassertion time */ + u32 adv_on; /* Assertion time */ + u32 adv_rd_off; /* Read deassertion time */ + u32 adv_wr_off; /* Write deassertion time */ /* WE signals timings corresponding to GPMC_CONFIG4 */ - u16 we_on; /* WE assertion time */ - u16 we_off; /* WE deassertion time */ + u32 we_on; /* WE assertion time */ + u32 we_off; /* WE deassertion time */ /* OE signals timings corresponding to GPMC_CONFIG4 */ - u16 oe_on; /* OE assertion time */ - u16 oe_off; /* OE deassertion time */ + u32 oe_on; /* OE assertion time */ + u32 oe_off; /* OE deassertion time */ /* Access time and cycle time timings corresponding to GPMC_CONFIG5 */ - u16 page_burst_access; /* Multiple access word delay */ - u16 access; /* Start-cycle to first data valid delay */ - u16 rd_cycle; /* Total read cycle time */ - u16 wr_cycle; /* Total write cycle time */ + u32 page_burst_access; /* Multiple access word delay */ + u32 access; /* Start-cycle to first data valid delay */ + u32 rd_cycle; /* Total read cycle time */ + u32 wr_cycle; /* Total write cycle time */ - u16 bus_turnaround; - u16 cycle2cycle_delay; + u32 bus_turnaround; + u32 cycle2cycle_delay; - u16 wait_monitoring; - u16 clk_activation; + u32 wait_monitoring; + u32 clk_activation; /* The following are only on OMAP3430 */ - u16 wr_access; /* WRACCESSTIME */ - u16 wr_data_mux_bus; /* WRDATAONADMUXBUS */ + u32 wr_access; /* WRACCESSTIME */ + u32 wr_data_mux_bus; /* WRDATAONADMUXBUS */ struct gpmc_bool_timings bool_timings; }; +/* Device timings in picoseconds */ +struct gpmc_device_timings { + u32 t_ceasu; /* address setup to CS valid */ + u32 t_avdasu; /* address setup to ADV valid */ + /* XXX: try to combine t_avdp_r & t_avdp_w. Issue is + * of tusb using these timings even for sync whilst + * ideally for adv_rd/(wr)_off it should have considered + * t_avdh instead. This indirectly necessitates r/w + * variations of t_avdp as it is possible to have one + * sync & other async + */ + u32 t_avdp_r; /* ADV low time (what about t_cer ?) */ + u32 t_avdp_w; + u32 t_aavdh; /* address hold time */ + u32 t_oeasu; /* address setup to OE valid */ + u32 t_aa; /* access time from ADV assertion */ + u32 t_iaa; /* initial access time */ + u32 t_oe; /* access time from OE assertion */ + u32 t_ce; /* access time from CS asertion */ + u32 t_rd_cycle; /* read cycle time */ + u32 t_cez_r; /* read CS deassertion to high Z */ + u32 t_cez_w; /* write CS deassertion to high Z */ + u32 t_oez; /* OE deassertion to high Z */ + u32 t_weasu; /* address setup to WE valid */ + u32 t_wpl; /* write assertion time */ + u32 t_wph; /* write deassertion time */ + u32 t_wr_cycle; /* write cycle time */ + + u32 clk; + u32 t_bacc; /* burst access valid clock to output delay */ + u32 t_ces; /* CS setup time to clk */ + u32 t_avds; /* ADV setup time to clk */ + u32 t_avdh; /* ADV hold time from clk */ + u32 t_ach; /* address hold time from clk */ + u32 t_rdyo; /* clk to ready valid */ + + u32 t_ce_rdyz; /* XXX: description ?, or use t_cez instead */ + u32 t_ce_avd; /* CS on to ADV on delay */ + + /* XXX: check the possibility of combining + * cyc_aavhd_oe & cyc_aavdh_we + */ + u8 cyc_aavdh_oe;/* read address hold time in cycles */ + u8 cyc_aavdh_we;/* write address hold time in cycles */ + u8 cyc_oe; /* access time from OE assertion in cycles */ + u8 cyc_wpl; /* write deassertion time in cycles */ + u32 cyc_iaa; /* initial access time in cycles */ + + bool mux; /* address & data muxed */ + bool sync_write;/* synchronous write */ + bool sync_read; /* synchronous read */ + + /* extra delays */ + bool ce_xdelay; + bool avd_xdelay; + bool oe_xdelay; + bool we_xdelay; +}; + +extern int gpmc_calc_timings(struct gpmc_timings *gpmc_t, + struct gpmc_device_timings *dev_t); + extern void gpmc_update_nand_reg(struct gpmc_nand_regs *reg, int cs); extern int gpmc_get_client_irq(unsigned irq_config); |