Hello! On 02/19/2019 09:36 AM, Vignesh R (by way of Boris Brezillon <bbrezillon@xxxxxxxxxx>) wrote: > 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 Need space before (. > 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. > > But, Hyperbus memory controllers seem to abstract implementation details > and expose a simple MMIO interface to access connected flash. > > Add support for registering HyperFlash devices with MTD framework. MTD > maps framework along with CFI chip support framework are used to support > communicate with flash. Communicating. > Framework is modelled along the lines of spi-nor framework. HyperBus > memory controller(HBMC) drivers call hb_register_device() to register a Again, space needed before (. > 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. > > Some HBMC masters need calibration/training sequence[3] to be carried > out, in order for DLL inside the controller to lock, by reading a known > string/pattern. This is done by repeatedly reading CFI Query > Identification String. Calibration needs to be done before try to detect Trying. > flash as part of CFI flash probe. > > HyperRAM is not supported atm. ATM? > HyperBus specification can be found at[1] > HyperFlash datasheet can be found at[2] > > [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 > > Signed-off-by: Vignesh R <vigneshr@xxxxxx> [...] > diff --git a/drivers/mtd/hyperbus/Kconfig b/drivers/mtd/hyperbus/Kconfig > new file mode 100644 > index 000000000000..02c38afc5c50 > --- /dev/null > +++ b/drivers/mtd/hyperbus/Kconfig > @@ -0,0 +1,23 @@ > +menuconfig MTD_HYPERBUS > + tristate "Hyperbus support" > + select MTD_CFI > + select MTD_MAP_BANK_WIDTH_2 > + select MTD_CFI_AMDSTD > + select MTD_COMPLEX_MAPPINGS > + help > + This is the framework for the Hyperbus which can be used by > + the Hyperbus Controller driver to commmunicate with ^^^ Too many m's. :-) > + Hyperflash. See Cypress Hyperbus specification for more > + details > + > + > +if MTD_HYPERBUS > + > +config HBMC_AM654 > + tristate "Hyperbus controller driver for AM65x SoC" > + help > + This is the driver for Hyperbus controller on TI's AM65x and > + other SoCs > + > +endif # MTD_HYPERBUS The above clearly belongs to patch #5. > + No empty lines at end of file, please... > diff --git a/drivers/mtd/hyperbus/Makefile b/drivers/mtd/hyperbus/Makefile > new file mode 100644 > index 000000000000..64e377d7f636 > --- /dev/null > +++ b/drivers/mtd/hyperbus/Makefile > @@ -0,0 +1,4 @@ > +# SPDX-License-Identifier: GPL-2.0 > + > +obj-$(CONFIG_MTD_HYPERBUS) += core.o > +obj-$(CONFIG_HBMC_AM654) += hbmc_am654.o The above line clearly belongs to patch #5 as well... > diff --git a/drivers/mtd/hyperbus/core.c b/drivers/mtd/hyperbus/core.c > new file mode 100644 > index 000000000000..d3d44aab7503 > --- /dev/null > +++ b/drivers/mtd/hyperbus/core.c > @@ -0,0 +1,167 @@ > +// SPDX-License-Identifier: GPL-2.0 > +// > +// Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/ > +// Author: Vignesh R <vigneshr@xxxxxx> > + > +#include <linux/err.h> > +#include <linux/kernel.h> > +#include <linux/mtd/hyperbus.h> > +#include <linux/mtd/map.h> > +#include <linux/mtd/mtd.h> > +#include <linux/mtd/cfi.h> > +#include <linux/of.h> > +#include <linux/of_address.h> > +#include <linux/types.h> > + > +#define HB_CALIB_COUNT 25 Isn't this controller specific? [...] > +/* Calibrate HBMC by repeatedly reading "QRY" string from CFI space */ > +static int hb_calibrate(struct hb_device *hbdev) s/int/bool/, perhaps? [...] > +int hb_register_device(struct hb_device *hbdev) > +{ > + struct resource res; > + struct device *dev; > + struct device_node *np; > + struct map_info *map; > + struct hb_ops *ops; > + int err; > + > + if (!hbdev || !hbdev->dev || !hbdev->np) { > + pr_err("hyperbus: please fill all the necessary fields!\n"); > + return -EINVAL; > + } > + > + np = hbdev->np; > + if (!of_device_is_compatible(np, "cypress,hyperflash")) > + return -ENODEV; > + > + hbdev->memtype = HYPERFLASH; > + > + if (of_address_to_resource(np, 0, &res)) Isn't the direct mapping property of the HF controller, not of HyperFlash itself? > + return -EINVAL; > + > + dev = hbdev->dev; > + map = &hbdev->map; > + map->size = resource_size(&res); > + map->virt = devm_ioremap_resource(dev, &res); > + if (IS_ERR(map->virt)) > + return PTR_ERR(map->virt); > + > + map->name = dev_name(dev); > + map->bankwidth = 2; > + > + simple_map_init(map); It's not that simple, I'm afraid -- e.g. Renesas RPC-IF has read and write mappings in the separate memory resources. [...] > + if (hbdev->needs_calib) { > + err = hb_calibrate(hbdev); > + if (!err) { Why call this variable 'err' when it indicates successful calibration? > + dev_err(hbdev->dev, "Calibration failed\n"); > + return -ENODEV; > + } > + } > + > + hbdev->mtd = do_map_probe("cfi_probe", map); > + if (!hbdev->mtd) { > + dev_err(hbdev->dev, "probing failed\n"); "map probe", perhaps? > + return -ENXIO; > + } > + > + hbdev->mtd->dev.parent = hbdev->dev; > + mtd_set_of_node(hbdev->mtd, np); > + > + err = mtd_device_register(hbdev->mtd, NULL, 0); > + if (err) { > + dev_err(hbdev->dev, "failed to register mtd device\n"); > + goto err_destroy; > + } > + hbdev->registered = true; > + > + return 0; > + > +err_destroy: The label and the code below doesn't seem necessary. Just do it above instead of *goto*. > + map_destroy(hbdev->mtd); > + return err; > +} [...] > diff --git a/include/linux/mtd/hyperbus.h b/include/linux/mtd/hyperbus.h > new file mode 100644 > index 000000000000..0aa11458c424 > --- /dev/null > +++ b/include/linux/mtd/hyperbus.h > @@ -0,0 +1,73 @@ > +/* SPDX-License-Identifier: GPL-2.0 > + * > + * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/ > + */ > + > +#ifndef __LINUX_MTD_HYPERBUS_H__ > +#define __LINUX_MTD_HYPERBUS_H__ > + > +#include <linux/mtd/map.h> > + > +enum hb_memtype { I'm for the full hyperbus_ prefixes, it's not that long and seems clearer. [...] MBR, Sergei
