| Message ID | 20190423104814.5762-1-vigneshr@ti.com |
|---|---|
| Headers | show |
| Series | MTD: Add Initial Hyperbus support | expand |
Hello! On 04/23/2019 01:48 PM, Vignesh Raghavendra wrote: > HyperFlash devices are compliant with CFI AMD/Fujitsu Extended Command > Set(0x0002) for flash operations, therefore drivers/mtd/chips/cfi_cmdset_0002.c > can be used as is. But these devices do not support DQ polling method of > determining chip ready/good status. These flashes provide Status > Register whose bits can be polled to know status of flash operation. > > Cypress HyperFlash datasheet here[1], talks about CFI Amd/Fujitsu > Extended Query version 1.5. Bit 0 of "Software Features supported" field > of CFI Primary Vendor-Specific Extended Query table indicates > presence/absence of status register and Bit 1 indicates whether or not > DQ polling is supported. Using these bits, its possible to determine > whether flash supports DQ polling or need to use Status Register. > > Add support for polling Status Register to know device ready/status of > erase/write operations when DQ polling is not supported. > Print error messages on erase/program failure by looking at related > Status Register bits. > > [1] https://www.cypress.com/file/213346/download > > Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com> Sorry, only superficial review, I'm not an MTD expert. :-) > --- > drivers/mtd/chips/cfi_cmdset_0002.c | 90 +++++++++++++++++++++++++++++ > include/linux/mtd/cfi.h | 5 ++ > 2 files changed, 95 insertions(+) > > diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c > index 7b7286b4d81e..55c4d81098d5 100644 > --- a/drivers/mtd/chips/cfi_cmdset_0002.c > +++ b/drivers/mtd/chips/cfi_cmdset_0002.c > @@ -49,6 +49,16 @@ > #define SST49LF008A 0x005a > #define AT49BV6416 0x00d6 > > +/* > + * Status Register bit description. Used by flash devices that don't > + * support DQ polling (Eg.: HyperFlash) It's "e.g. " :-) [...] > @@ -97,6 +107,48 @@ static struct mtd_chip_driver cfi_amdstd_chipdrv = { > .module = THIS_MODULE > }; > > +/* > + * Use status register to poll for Erase/write completion when DQ is not > + * supported. This is indicated by Bit[1:0] of SoftwareFeatures field in > + * CFI Primary Vendor-Specific Extended Query table 1.5 > + */ > +static int cfi_use_status_reg(struct cfi_private *cfi) > +{ > + struct cfi_pri_amdstd *extp = cfi->cmdset_priv; > + > + return (extp->MinorVersion >= '5') && Parens not needed here, especially as the next operator isn't enclosed. > + (extp->SoftwareFeatures & 0x3) == 0x1; > +} [...] MBR, Sergei
On 04/23/2019 01:48 PM, Vignesh Raghavendra wrote: > Add driver for HyperBus memory controller on TI's AM654 SoC. Programming > IP is pretty simple and provides direct memory mapped access to > connected Flash devices. > > Add basic support for the IP without DMA. Second chipSelect is not > supported for now. > > Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com> [...] > diff --git a/drivers/mtd/hyperbus/hbmc-am654.c b/drivers/mtd/hyperbus/hbmc-am654.c > new file mode 100644 > index 000000000000..f458d7226df9 > --- /dev/null > +++ b/drivers/mtd/hyperbus/hbmc-am654.c > @@ -0,0 +1,115 @@ > +// SPDX-License-Identifier: GPL-2.0 > +// > +// Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/ > +// Author: Vignesh Raghavendra <vigneshr@ti.com> > + > +#include <linux/err.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/mtd/hyperbus.h> > +#include <linux/mtd/mtd.h> > +#include <linux/mux/consumer.h> > +#include <linux/of.h> > +#include <linux/platform_device.h> > +#include <linux/pm_runtime.h> > +#include <linux/types.h> > + > +struct am654_hbmc_priv { > + struct hyperbus_ctlr ctlr; > + struct hyperbus_device hbdev; > + void __iomem *regbase; You don't seem to use this field. [...] MBR, Sergei
Cypress HyperBus is Low Signal Count, High Performance Double Data Rate Bus interface between a host system master and one or more slave interfaces. HyperBus is used to connect microprocessor, microcontroller, or ASIC devices with random access NOR flash memory(called HyperFlash) or self refresh DRAM(called HyperRAM). Its a 8-bit data bus (DQ[7:0]) with Read-Write Data Strobe (RWDS) signal and either Single-ended clock(3.0V parts) or Differential clock (1.8V parts). It uses ChipSelect lines to select b/w multiple slaves. At bus level, it follows a separate protocol described in HyperBus specification[1]. HyperFlash follows CFI AMD/Fujitsu Extended Command Set (0x0002) similar to that of existing parallel NORs. Since Hyperbus is x8 DDR bus, its equivalent to x16 parallel NOR flash wrt bits per clk. But Hyperbus operates at >166MHz frequencies. HyperRAM provides direct random read/write access to flash memory array. Framework is modelled along the lines of spi-nor framework. HyperBus memory controller(HBMC) drivers call hyperbus_register_device() to register a single HyperFlash device. HyperFlash core parses MMIO access information from DT, sets up the map_info struct, probes CFI flash and registers it with MTD framework. This is an early RFC, to know if its okay to use maps framework and existing CFI compliant flash support code to support Hyperflash Also would like input on different types of HBMC master IPs out there and their programming sequences. Would appreciate any testing/review. Tested on modified TI AM654 EVM with Cypress Hyperflash S26KS512 by creating a UBIFS partition and writing and reading files to it. Stress tested by writing/reading 16MB flash repeatedly at different offsets using dd commmand. HyperBus specification can be found at[1] HyperFlash datasheet can be found at[2] TI's HBMC controller details at[3] [1] https://www.cypress.com/file/213356/download [2] https://www.cypress.com/file/213346/download [3] http://www.ti.com/lit/ug/spruid7b/spruid7b.pdf Table 12-5741. HyperFlash Access Sequence Change log: Since v3: * Drop reading QRY string twice in hyperbus_calibrate() * Fix doc/misc comments on v3. Since RFC v2: * use map_word_xxx() for handling status register to support interleaved flashes as suggested by Joakim Tjernlund <Joakim.Tjernlund@infinera.com> * Report error status/messages on erase/program failure by looking at status register bits. * Add "cfi-flash" as fallback compatible for cypress,hyperflash * Add support to select between HyperBus and OSPI using mmio mux Since RFC v1: * Re-work Hyperbus core to provide separate struct representation for controller and slave devices * Rename all files and func names to have hyperbus_ prefix * Provide default calibration routine for use by controller drivers * Fix up errors with patch spliting * Address comments by Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Vignesh Raghavendra (5): mtd: cfi_cmdset_0002: Add support for polling status register dt-bindings: mtd: Add binding documentation for HyperFlash mtd: Add support for HyperBus memory devices dt-bindings: mtd: Add bindings for TI's AM654 HyperBus memory controller mtd: hyperbus: Add driver for TI's HyperBus memory controller .../bindings/mtd/cypress,hyperflash.txt | 13 ++ .../devicetree/bindings/mtd/ti,am654-hbmc.txt | 32 +++ MAINTAINERS | 8 + drivers/mtd/Kconfig | 2 + drivers/mtd/Makefile | 1 + drivers/mtd/chips/cfi_cmdset_0002.c | 90 +++++++++ drivers/mtd/hyperbus/Kconfig | 23 +++ drivers/mtd/hyperbus/Makefile | 4 + drivers/mtd/hyperbus/hbmc-am654.c | 115 +++++++++++ drivers/mtd/hyperbus/hyperbus-core.c | 191 ++++++++++++++++++ include/linux/mtd/cfi.h | 5 + include/linux/mtd/hyperbus.h | 91 +++++++++ 12 files changed, 575 insertions(+) create mode 100644 Documentation/devicetree/bindings/mtd/cypress,hyperflash.txt create mode 100644 Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt create mode 100644 drivers/mtd/hyperbus/Kconfig create mode 100644 drivers/mtd/hyperbus/Makefile create mode 100644 drivers/mtd/hyperbus/hbmc-am654.c create mode 100644 drivers/mtd/hyperbus/hyperbus-core.c create mode 100644 include/linux/mtd/hyperbus.h