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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-24 08:46:03 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-24 08:46:03 -0700 |
| commit | cf9610f9116d55c5a66ef9f1faecacabd93a9322 (patch) | |
| tree | 757a3d280760c654767631cab5ad8af2d86d1848 /Documentation/driver-api/memory-devices | |
| download | linux-stable-cf9610f9116d55c5a66ef9f1faecacabd93a9322.tar.gz linux-stable-cf9610f9116d55c5a66ef9f1faecacabd93a9322.zip | |
Merge tag 'pinctrl-v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrlgrafted
Pull pin control updates from Linus Walleij:
"Core changes:
- Use the non-blocking mux_state_try_select() in the generic MUX pin
control back-end
- Free pin maps on pinctrl_generic_to_map() failure in the core
helpers
New hardware pin control:
- Qualcomm Maili TLMM SoC, PMG1110 PMIC, and Eliza LPASS LPI TLMM SoC
(this is for the low power audio, LPASS = Low Power Audio SubSystem
portions)
- Upboard support on top of the Intel pin controller
- Apple T6030 and T6031 support (just compatible strings)
- Samsung Exynos 8855 SoC
- Mediatek MT6858 SoC
- Rockchip RK3308B and RV1106 SoCs
- Airoha EN7523 and AN7563 SoCs
Improvements:
- Qualcomm TLMM GPIOs are unconditionally marked as wakeup capable
- Qualcomm improvements on top of the Qualcomm PDC (power domain
controller) irqchip improvements from tglx:s tree
- Qualcomm IPQ806x and IPQ9650 non-urgent pin grop fixups
- The NPCM8xx driver has been put into shape fixing many pin and
group definitions
- Some non-urgent Tegra 264 pin assignments are fixed up
- Some non-urgent fixups to Airoha AN7581 and AN7583 registers and
pin assignments, missing features etc"
* tag 'pinctrl-v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (130 commits)
dt-bindings: pinctrl: Convert TI DA850 pupd to DT schema
pinctrl: meson: sync some modify from A4
pinctrl: meson: a4: Add input enable pin configuration
pinctrl: realtek: rtd1625: remove unused group name spdif_sel
pinctrl: realtek: rtd1625: fix base_bit for VE4 GPIO 13
dt-bindings: pinctrl: microchip,pic32mzda-pinctrl: Convert to DT schema
Revert "Merge branch 'ib-rsk7204' into devel"
pinctrl: rockchip: Add RV1106 pinctrl support
dt-bindings: pinctrl: rockchip: Add RV1106 compatible
pinctrl: rockchip: Decode drive strength in the get function
pinctrl: fix PINCTRL_GENERIC_MUX not always being selectable
pinctrl: airoha: add support of an7563 SoC
dt-bindings: pinctrl: airoha: add support of an7563 pin controller
pinctrl: airoha: try to find chip scu node by phandle first
pinctrl: airoha: add support of en7523 SoC
dt-bindings: pinctrl: airoha: add support of en7523 pin controller
pinctrl: airoha: an7583: add support for olt pinmux
pinctrl: airoha: an7583: add support for pon_alt pinmux
pinctrl: airoha: an7583: add support for npu_uart pinmux
dt-bindings: pinctrl: airoha: an7583: add missed features
...
Diffstat (limited to 'Documentation/driver-api/memory-devices')
| -rw-r--r-- | Documentation/driver-api/memory-devices/index.rst | 11 | ||||
| -rw-r--r-- | Documentation/driver-api/memory-devices/ti-emif.rst | 64 | ||||
| -rw-r--r-- | Documentation/driver-api/memory-devices/ti-gpmc.rst | 179 |
3 files changed, 254 insertions, 0 deletions
diff --git a/Documentation/driver-api/memory-devices/index.rst b/Documentation/driver-api/memory-devices/index.rst new file mode 100644 index 000000000..3b6308113 --- /dev/null +++ b/Documentation/driver-api/memory-devices/index.rst @@ -0,0 +1,11 @@ +.. SPDX-License-Identifier: GPL-2.0 + +========================= +Memory Controller drivers +========================= + +.. toctree:: + :maxdepth: 1 + + ti-emif + ti-gpmc diff --git a/Documentation/driver-api/memory-devices/ti-emif.rst b/Documentation/driver-api/memory-devices/ti-emif.rst new file mode 100644 index 000000000..dea2ad9bc --- /dev/null +++ b/Documentation/driver-api/memory-devices/ti-emif.rst @@ -0,0 +1,64 @@ +.. SPDX-License-Identifier: GPL-2.0 + +=============================== +TI EMIF SDRAM Controller Driver +=============================== + +Author +====== +Aneesh V <aneesh@ti.com> + +Location +======== +driver/memory/emif.c + +Supported SoCs: +=============== +TI OMAP44xx +TI OMAP54xx + +Menuconfig option: +================== +Device Drivers + Memory devices + Texas Instruments EMIF driver + +Description +=========== +This driver is for the EMIF module available in Texas Instruments +SoCs. EMIF is an SDRAM controller that, based on its revision, +supports one or more of DDR2, DDR3, and LPDDR2 SDRAM protocols. +This driver takes care of only LPDDR2 memories presently. The +functions of the driver includes re-configuring AC timing +parameters and other settings during frequency, voltage and +temperature changes + +Platform Data (see include/linux/platform_data/emif_plat.h) +=========================================================== +DDR device details and other board dependent and SoC dependent +information can be passed through platform data (struct emif_platform_data) + +- DDR device details: 'struct ddr_device_info' +- Device AC timings: 'struct lpddr2_timings' and 'struct lpddr2_min_tck' +- Custom configurations: customizable policy options through + 'struct emif_custom_configs' +- IP revision +- PHY type + +Interface to the external world +=============================== +EMIF driver registers notifiers for voltage and frequency changes +affecting EMIF and takes appropriate actions when these are invoked. + +- freq_pre_notify_handling() +- freq_post_notify_handling() +- volt_notify_handling() + +Debugfs +======= +The driver creates two debugfs entries per device. + +- regcache_dump : dump of register values calculated and saved for all + frequencies used so far. +- mr4 : last polled value of MR4 register in the LPDDR2 device. MR4 + indicates the current temperature level of the device. diff --git a/Documentation/driver-api/memory-devices/ti-gpmc.rst b/Documentation/driver-api/memory-devices/ti-gpmc.rst new file mode 100644 index 000000000..b1bb86871 --- /dev/null +++ b/Documentation/driver-api/memory-devices/ti-gpmc.rst @@ -0,0 +1,179 @@ +.. SPDX-License-Identifier: GPL-2.0 + +======================================== +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: https://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). |
