| Message ID | 1397668667-27328-4-git-send-email-ynvich@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Sergei, A few more small comments. On Wed, Apr 16, 2014 at 09:17:15PM +0400, Sergei Ianovich wrote: > This provides an MTD device driver for 512kB of battery backed up SRAM > on ICPDAS LP-8X4X programmable automation controllers. > > SRAM chip is connected via FPGA and is not accessible without a driver, > unlike flash memory which is wired to CPU MMU. > > This SRAM becomes an excellent persisent storage of volatile process > data like counter values and sensor statuses. Storing those data in > flash or mmc card is not a viable solution. > > Signed-off-by: Sergei Ianovich <ynvich@gmail.com> > Reviewed-by: Brian Norris <computersforpeace@gmail.com> > --- > v3..v4 for Brian Norris 'Reviewed-by' > * add doc file for DT binding > * move DTS binding to a different patch (8/21) > * drop unused include directive > * drop safely unused callback > * drop non-default partion probe types > * drop duplicate error checks > * drop duplicate error reporting > * fixed error message on MTD registeration > * fixed module removal routine Thanks for the updates. This patch looks pretty good to me. > v2..v3 > * no changes (except number 08/16 -> 10/21) > > v0..v2 > * use device tree > * use devm helpers where possible > > .../devicetree/bindings/mtd/sram-lp8x4x.txt | 22 +++ > arch/arm/configs/lp8x4x_defconfig | 1 + > drivers/mtd/devices/Kconfig | 14 ++ > drivers/mtd/devices/Makefile | 1 + > drivers/mtd/devices/sram_lp8x4x.c | 204 +++++++++++++++++++++ > 5 files changed, 242 insertions(+) > create mode 100644 Documentation/devicetree/bindings/mtd/sram-lp8x4x.txt > create mode 100644 drivers/mtd/devices/sram_lp8x4x.c > > diff --git a/Documentation/devicetree/bindings/mtd/sram-lp8x4x.txt b/Documentation/devicetree/bindings/mtd/sram-lp8x4x.txt > new file mode 100644 > index 0000000..8b1e864 > --- /dev/null > +++ b/Documentation/devicetree/bindings/mtd/sram-lp8x4x.txt > @@ -0,0 +1,22 @@ > +512kB battery backed up SRAM on LP-8x4x industrial computers > + > +Required properties: > +- compatible : should be "icpdas,sram-lp8x4x" > + > +- reg: physical base addresses and region lengths of > + * IO memory range > + * SRAM page selector Are these region types pretty static for this type of hardware? If not, it helps to have a reg-names property in the DT, when there are 2 or more register resources. > +- eeprom-gpios : should point to active-low write enable GPIO I'm curious: your driver doesn't actually utilize this binding. Is this intentional? Is it actually optional? (I note that the example DT below doesn't have this property...) > + > +SRAM chip is connected via FPGA and is not accessible without a driver, > +unlike flash memory which is wired to CPU MMU. Driver is essentially > +an address translation routine. > + > +Example: > + > + sram@a000 { > + compatible = "icpdas,sram-lp8x4x"; > + reg = <0xa000 0x1000 > + 0x901e 0x1>; > + }; > diff --git a/arch/arm/configs/lp8x4x_defconfig b/arch/arm/configs/lp8x4x_defconfig > index d60e37a..17a4e6f 100644 > --- a/arch/arm/configs/lp8x4x_defconfig > +++ b/arch/arm/configs/lp8x4x_defconfig > @@ -57,6 +57,7 @@ CONFIG_MTD_CFI_ADV_OPTIONS=y > CONFIG_MTD_CFI_GEOMETRY=y > CONFIG_MTD_CFI_INTELEXT=y > CONFIG_MTD_PHYSMAP_OF=y > +CONFIG_MTD_SRAM_LP8X4X=y > CONFIG_PROC_DEVICETREE=y > CONFIG_BLK_DEV_LOOP=y > CONFIG_BLK_DEV_LOOP_MIN_COUNT=2 I can't take the defconfig update via MTD; it will need to go via the appropriate ARM tree (arm-soc?). So this hunk needs to move to another patch. > diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig > index 1210bc2..fc8552b 100644 > --- a/drivers/mtd/devices/Kconfig > +++ b/drivers/mtd/devices/Kconfig > @@ -225,4 +225,18 @@ config BCH_CONST_T > default 4 > endif > > +config MTD_SRAM_LP8X4X > + tristate "SRAM on ICPDAS LP-8X4X" > + depends on OF && ARCH_PXA > + ---help--- > + This provides an MTD device driver for 512kiB of battery backed up SRAM > + on ICPDAS LP-8X4X programmable automation controllers. > + > + SRAM chip is connected via FPGA and is not accessible without a driver, > + unlike flash memory which is wired to CPU MMU. > + > + Say N, unless you plan to run this kernel on LP-8X4X. > + > + If you say M, the module will be called sram_lp8x4x. > + > endmenu > diff --git a/drivers/mtd/devices/Makefile b/drivers/mtd/devices/Makefile > index c68868f..a7d86e2 100644 > --- a/drivers/mtd/devices/Makefile > +++ b/drivers/mtd/devices/Makefile > @@ -17,6 +17,7 @@ obj-$(CONFIG_MTD_SPEAR_SMI) += spear_smi.o > obj-$(CONFIG_MTD_SST25L) += sst25l.o > obj-$(CONFIG_MTD_BCM47XXSFLASH) += bcm47xxsflash.o > obj-$(CONFIG_MTD_ST_SPI_FSM) += st_spi_fsm.o > +obj-$(CONFIG_MTD_SRAM_LP8X4X) += sram_lp8x4x.o > > > CFLAGS_docg3.o += -I$(src) > diff --git a/drivers/mtd/devices/sram_lp8x4x.c b/drivers/mtd/devices/sram_lp8x4x.c > new file mode 100644 > index 0000000..4cfa70b > --- /dev/null > +++ b/drivers/mtd/devices/sram_lp8x4x.c > @@ -0,0 +1,204 @@ > +/* > + * linux/drivers/mtd/devices/lp8x4x_sram.c > + * > + * MTD Driver for SRAM on ICPDAS LP-8x4x > + * Copyright (C) 2013 Sergei Ianovich <ynvich@gmail.com> > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation or any later version. > + */ > + > +#include <linux/init.h> > +#include <linux/io.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/mtd/map.h> > +#include <linux/mtd/mtd.h> > +#include <linux/mtd/partitions.h> > +#include <linux/platform_device.h> > +#include <linux/of_device.h> > +#include <linux/slab.h> > +#include <linux/string_helpers.h> > +#include <linux/types.h> > + > +struct lp8x4x_sram_info { > + void __iomem *bank; > + void __iomem *virt; > + struct mutex lock; > + unsigned active_bank; > + struct mtd_info mtd; > +}; > + > +static int > +lp8x4x_sram_erase(struct mtd_info *mtd, struct erase_info *instr) > +{ > + struct lp8x4x_sram_info *info = mtd->priv; > + unsigned bank = instr->addr >> 11; > + unsigned offset = (instr->addr & 0x7ff) << 1; > + loff_t i; > + > + mutex_lock(&info->lock); > + if (unlikely(bank != info->active_bank)) { > + info->active_bank = bank; > + iowrite8(bank, info->bank); > + } > + for (i = 0; i < instr->len; i++) { > + iowrite8(0xff, info->virt + offset); > + offset += 2; > + if (unlikely(offset == 0)) { > + info->active_bank++; > + iowrite8(info->active_bank, info->bank); > + } > + } > + mutex_unlock(&info->lock); > + instr->state = MTD_ERASE_DONE; > + mtd_erase_callback(instr); > + > + return 0; > +} > + > +static int > +lp8x4x_sram_write(struct mtd_info *mtd, loff_t to, size_t len, > + size_t *retlen, const u_char *b) > +{ > + struct lp8x4x_sram_info *info = mtd->priv; > + unsigned bank = to >> 11; > + unsigned offset = (to & 0x7ff) << 1; > + loff_t i; > + > + mutex_lock(&info->lock); > + if (unlikely(bank != info->active_bank)) { > + info->active_bank = bank; > + iowrite8(bank, info->bank); > + } > + for (i = 0; i < len; i++) { > + iowrite8(b[i], info->virt + offset); > + offset += 2; > + if (unlikely(offset == 0)) { > + info->active_bank++; > + iowrite8(info->active_bank, info->bank); > + } > + } > + mutex_unlock(&info->lock); > + *retlen = len; > + return 0; > +} > + > +static int > +lp8x4x_sram_read(struct mtd_info *mtd, loff_t from, size_t len, > + size_t *retlen, u_char *b) > +{ > + struct lp8x4x_sram_info *info = mtd->priv; > + unsigned bank = from >> 11; > + unsigned offset = (from & 0x7ff) << 1; > + loff_t i; > + > + mutex_lock(&info->lock); > + if (unlikely(bank != info->active_bank)) { > + info->active_bank = bank; > + iowrite8(bank, info->bank); > + } > + for (i = 0; i < len; i++) { > + b[i] = ioread8(info->virt + offset); > + offset += 2; > + if (unlikely(offset == 0)) { > + info->active_bank++; > + iowrite8(info->active_bank, info->bank); > + } > + } > + mutex_unlock(&info->lock); > + *retlen = len; > + return 0; > +} > + > +static struct of_device_id of_flash_match[] = { > + { > + .compatible = "icpdas,sram-lp8x4x", > + }, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, of_flash_match); > + > +static int > +lp8x4x_sram_probe(struct platform_device *pdev) > +{ > + const struct of_device_id *match; > + struct lp8x4x_sram_info *info; > + struct resource *res_virt, *res_bank; > + char sz_str[16]; > + struct mtd_part_parser_data ppdata; > + int err = 0; > + > + match = of_match_device(of_flash_match, &pdev->dev); > + if (!match) > + return -EINVAL; Does this of_match_device() serve any particular purpose? Your driver already matches against these IDs, and you're not actually retrieving any of-data from the match, so this looks redundant. > + > + info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL); > + if (!info) > + return -ENOMEM; > + > + res_virt = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + info->virt = devm_ioremap_resource(&pdev->dev, res_virt); > + if (IS_ERR(info->virt)) > + return PTR_ERR(info->virt); > + > + res_bank = platform_get_resource(pdev, IORESOURCE_MEM, 1); > + info->bank = devm_ioremap_resource(&pdev->dev, res_bank); > + if (IS_ERR(info->bank)) > + return PTR_ERR(info->bank); > + > + info->mtd.priv = info; > + info->mtd.name = "SRAM"; Are you absolutely sure there is only ever a single SRAM device on a given system? Because otherwise, you will get redundantly-named MTD's. If the answer is no, you might consider a unique naming scheme. > + info->mtd.type = MTD_RAM; > + info->mtd.flags = MTD_CAP_RAM; > + info->mtd.size = resource_size(res_virt) << 7; > + info->mtd.erasesize = 512; > + info->mtd.writesize = 4; > + info->mtd._erase = lp8x4x_sram_erase; > + info->mtd._write = lp8x4x_sram_write; > + info->mtd._read = lp8x4x_sram_read; > + info->mtd.owner = THIS_MODULE; > + > + mutex_init(&info->lock); > + iowrite8(info->active_bank, info->bank); > + platform_set_drvdata(pdev, info); > + > + ppdata.of_node = pdev->dev.of_node; > + err = mtd_device_parse_register(&info->mtd, NULL, &ppdata, > + NULL, 0); > + > + if (err < 0) { > + dev_err(&pdev->dev, "failed to register MTD\n"); > + return err; > + } > + > + string_get_size(info->mtd.size, STRING_UNITS_2, sz_str, > + sizeof(sz_str)); > + dev_info(&pdev->dev, "using %s SRAM on LP-8X4X as %s\n", sz_str, > + dev_name(&info->mtd.dev)); > + return 0; > +} > + > +static int > +lp8x4x_sram_remove(struct platform_device *dev) > +{ > + struct lp8x4x_sram_info *info = platform_get_drvdata(dev); > + return mtd_device_unregister(&info->mtd); > +} > + > +static struct platform_driver lp8x4x_sram_driver = { > + .driver = { > + .name = "sram-lp8x4x", > + .owner = THIS_MODULE, > + .of_match_table = of_flash_match, > + }, > + .probe = lp8x4x_sram_probe, > + .remove = lp8x4x_sram_remove, > +}; > + > +module_platform_driver(lp8x4x_sram_driver); > + > +MODULE_LICENSE("GPL"); > +MODULE_AUTHOR("Sergei Ianovich <ynvich@gmail.com>"); > +MODULE_DESCRIPTION("MTD driver for SRAM on ICPDAS LP-8x4x"); Thanks, Brian
Hi Brian, On Wed, 2014-04-30 at 10:21 -0700, Brian Norris wrote: > A few more small comments. > > On Wed, Apr 16, 2014 at 09:17:15PM +0400, Sergei Ianovich wrote: > > +++ b/Documentation/devicetree/bindings/mtd/sram-lp8x4x.txt > > @@ -0,0 +1,22 @@ > > +512kB battery backed up SRAM on LP-8x4x industrial computers > > + > > +Required properties: > > +- compatible : should be "icpdas,sram-lp8x4x" > > + > > +- reg: physical base addresses and region lengths of > > + * IO memory range > > + * SRAM page selector > > Are these region types pretty static for this type of hardware? If not, > it helps to have a reg-names property in the DT, when there are 2 or > more register resources. The regions are fixed. The addresses are hard-wired. > > +- eeprom-gpios : should point to active-low write enable GPIO > > I'm curious: your driver doesn't actually utilize this binding. Is this > intentional? Is it actually optional? (I note that the example DT below > doesn't have this property...) Thanks for noticing. It's an artifact of copy-paste. I'll drop this. > > +++ b/arch/arm/configs/lp8x4x_defconfig > > @@ -57,6 +57,7 @@ CONFIG_MTD_CFI_ADV_OPTIONS=y > > CONFIG_MTD_CFI_GEOMETRY=y > > CONFIG_MTD_CFI_INTELEXT=y > > CONFIG_MTD_PHYSMAP_OF=y > > +CONFIG_MTD_SRAM_LP8X4X=y > > CONFIG_PROC_DEVICETREE=y > > CONFIG_BLK_DEV_LOOP=y > > CONFIG_BLK_DEV_LOOP_MIN_COUNT=2 > > I can't take the defconfig update via MTD; it will need to go via the > appropriate ARM tree (arm-soc?). So this hunk needs to move to another > patch. Sure. I'll remove this chunk and put it into main device patch. > > + match = of_match_device(of_flash_match, &pdev->dev); > > + if (!match) > > + return -EINVAL; > > Does this of_match_device() serve any particular purpose? Your driver > already matches against these IDs, and you're not actually retrieving > any of-data from the match, so this looks redundant. Point taken, I'll drop this. > > + > > + info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL); > > + if (!info) > > + return -ENOMEM; > > + > > + res_virt = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > + info->virt = devm_ioremap_resource(&pdev->dev, res_virt); > > + if (IS_ERR(info->virt)) > > + return PTR_ERR(info->virt); > > + > > + res_bank = platform_get_resource(pdev, IORESOURCE_MEM, 1); > > + info->bank = devm_ioremap_resource(&pdev->dev, res_bank); > > + if (IS_ERR(info->bank)) > > + return PTR_ERR(info->bank); > > + > > + info->mtd.priv = info; > > + info->mtd.name = "SRAM"; > > Are you absolutely sure there is only ever a single SRAM device on a > given system? Because otherwise, you will get redundantly-named MTD's. > If the answer is no, you might consider a unique naming scheme. Like .999999 sure. This one is hard-wired. There is no extension slots to plug in any memory device. I'll post a new version with the rest of the series. Thanks for reviewing.
diff --git a/Documentation/devicetree/bindings/mtd/sram-lp8x4x.txt b/Documentation/devicetree/bindings/mtd/sram-lp8x4x.txt new file mode 100644 index 0000000..8b1e864 --- /dev/null +++ b/Documentation/devicetree/bindings/mtd/sram-lp8x4x.txt @@ -0,0 +1,22 @@ +512kB battery backed up SRAM on LP-8x4x industrial computers + +Required properties: +- compatible : should be "icpdas,sram-lp8x4x" + +- reg: physical base addresses and region lengths of + * IO memory range + * SRAM page selector + +- eeprom-gpios : should point to active-low write enable GPIO + +SRAM chip is connected via FPGA and is not accessible without a driver, +unlike flash memory which is wired to CPU MMU. Driver is essentially +an address translation routine. + +Example: + + sram@a000 { + compatible = "icpdas,sram-lp8x4x"; + reg = <0xa000 0x1000 + 0x901e 0x1>; + }; diff --git a/arch/arm/configs/lp8x4x_defconfig b/arch/arm/configs/lp8x4x_defconfig index d60e37a..17a4e6f 100644 --- a/arch/arm/configs/lp8x4x_defconfig +++ b/arch/arm/configs/lp8x4x_defconfig @@ -57,6 +57,7 @@ CONFIG_MTD_CFI_ADV_OPTIONS=y CONFIG_MTD_CFI_GEOMETRY=y CONFIG_MTD_CFI_INTELEXT=y CONFIG_MTD_PHYSMAP_OF=y +CONFIG_MTD_SRAM_LP8X4X=y CONFIG_PROC_DEVICETREE=y CONFIG_BLK_DEV_LOOP=y CONFIG_BLK_DEV_LOOP_MIN_COUNT=2 diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig index 1210bc2..fc8552b 100644 --- a/drivers/mtd/devices/Kconfig +++ b/drivers/mtd/devices/Kconfig @@ -225,4 +225,18 @@ config BCH_CONST_T default 4 endif +config MTD_SRAM_LP8X4X + tristate "SRAM on ICPDAS LP-8X4X" + depends on OF && ARCH_PXA + ---help--- + This provides an MTD device driver for 512kiB of battery backed up SRAM + on ICPDAS LP-8X4X programmable automation controllers. + + SRAM chip is connected via FPGA and is not accessible without a driver, + unlike flash memory which is wired to CPU MMU. + + Say N, unless you plan to run this kernel on LP-8X4X. + + If you say M, the module will be called sram_lp8x4x. + endmenu diff --git a/drivers/mtd/devices/Makefile b/drivers/mtd/devices/Makefile index c68868f..a7d86e2 100644 --- a/drivers/mtd/devices/Makefile +++ b/drivers/mtd/devices/Makefile @@ -17,6 +17,7 @@ obj-$(CONFIG_MTD_SPEAR_SMI) += spear_smi.o obj-$(CONFIG_MTD_SST25L) += sst25l.o obj-$(CONFIG_MTD_BCM47XXSFLASH) += bcm47xxsflash.o obj-$(CONFIG_MTD_ST_SPI_FSM) += st_spi_fsm.o +obj-$(CONFIG_MTD_SRAM_LP8X4X) += sram_lp8x4x.o CFLAGS_docg3.o += -I$(src) diff --git a/drivers/mtd/devices/sram_lp8x4x.c b/drivers/mtd/devices/sram_lp8x4x.c new file mode 100644 index 0000000..4cfa70b --- /dev/null +++ b/drivers/mtd/devices/sram_lp8x4x.c @@ -0,0 +1,204 @@ +/* + * linux/drivers/mtd/devices/lp8x4x_sram.c + * + * MTD Driver for SRAM on ICPDAS LP-8x4x + * Copyright (C) 2013 Sergei Ianovich <ynvich@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation or any later version. + */ + +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mtd/map.h> +#include <linux/mtd/mtd.h> +#include <linux/mtd/partitions.h> +#include <linux/platform_device.h> +#include <linux/of_device.h> +#include <linux/slab.h> +#include <linux/string_helpers.h> +#include <linux/types.h> + +struct lp8x4x_sram_info { + void __iomem *bank; + void __iomem *virt; + struct mutex lock; + unsigned active_bank; + struct mtd_info mtd; +}; + +static int +lp8x4x_sram_erase(struct mtd_info *mtd, struct erase_info *instr) +{ + struct lp8x4x_sram_info *info = mtd->priv; + unsigned bank = instr->addr >> 11; + unsigned offset = (instr->addr & 0x7ff) << 1; + loff_t i; + + mutex_lock(&info->lock); + if (unlikely(bank != info->active_bank)) { + info->active_bank = bank; + iowrite8(bank, info->bank); + } + for (i = 0; i < instr->len; i++) { + iowrite8(0xff, info->virt + offset); + offset += 2; + if (unlikely(offset == 0)) { + info->active_bank++; + iowrite8(info->active_bank, info->bank); + } + } + mutex_unlock(&info->lock); + instr->state = MTD_ERASE_DONE; + mtd_erase_callback(instr); + + return 0; +} + +static int +lp8x4x_sram_write(struct mtd_info *mtd, loff_t to, size_t len, + size_t *retlen, const u_char *b) +{ + struct lp8x4x_sram_info *info = mtd->priv; + unsigned bank = to >> 11; + unsigned offset = (to & 0x7ff) << 1; + loff_t i; + + mutex_lock(&info->lock); + if (unlikely(bank != info->active_bank)) { + info->active_bank = bank; + iowrite8(bank, info->bank); + } + for (i = 0; i < len; i++) { + iowrite8(b[i], info->virt + offset); + offset += 2; + if (unlikely(offset == 0)) { + info->active_bank++; + iowrite8(info->active_bank, info->bank); + } + } + mutex_unlock(&info->lock); + *retlen = len; + return 0; +} + +static int +lp8x4x_sram_read(struct mtd_info *mtd, loff_t from, size_t len, + size_t *retlen, u_char *b) +{ + struct lp8x4x_sram_info *info = mtd->priv; + unsigned bank = from >> 11; + unsigned offset = (from & 0x7ff) << 1; + loff_t i; + + mutex_lock(&info->lock); + if (unlikely(bank != info->active_bank)) { + info->active_bank = bank; + iowrite8(bank, info->bank); + } + for (i = 0; i < len; i++) { + b[i] = ioread8(info->virt + offset); + offset += 2; + if (unlikely(offset == 0)) { + info->active_bank++; + iowrite8(info->active_bank, info->bank); + } + } + mutex_unlock(&info->lock); + *retlen = len; + return 0; +} + +static struct of_device_id of_flash_match[] = { + { + .compatible = "icpdas,sram-lp8x4x", + }, + { }, +}; +MODULE_DEVICE_TABLE(of, of_flash_match); + +static int +lp8x4x_sram_probe(struct platform_device *pdev) +{ + const struct of_device_id *match; + struct lp8x4x_sram_info *info; + struct resource *res_virt, *res_bank; + char sz_str[16]; + struct mtd_part_parser_data ppdata; + int err = 0; + + match = of_match_device(of_flash_match, &pdev->dev); + if (!match) + return -EINVAL; + + info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL); + if (!info) + return -ENOMEM; + + res_virt = platform_get_resource(pdev, IORESOURCE_MEM, 0); + info->virt = devm_ioremap_resource(&pdev->dev, res_virt); + if (IS_ERR(info->virt)) + return PTR_ERR(info->virt); + + res_bank = platform_get_resource(pdev, IORESOURCE_MEM, 1); + info->bank = devm_ioremap_resource(&pdev->dev, res_bank); + if (IS_ERR(info->bank)) + return PTR_ERR(info->bank); + + info->mtd.priv = info; + info->mtd.name = "SRAM"; + info->mtd.type = MTD_RAM; + info->mtd.flags = MTD_CAP_RAM; + info->mtd.size = resource_size(res_virt) << 7; + info->mtd.erasesize = 512; + info->mtd.writesize = 4; + info->mtd._erase = lp8x4x_sram_erase; + info->mtd._write = lp8x4x_sram_write; + info->mtd._read = lp8x4x_sram_read; + info->mtd.owner = THIS_MODULE; + + mutex_init(&info->lock); + iowrite8(info->active_bank, info->bank); + platform_set_drvdata(pdev, info); + + ppdata.of_node = pdev->dev.of_node; + err = mtd_device_parse_register(&info->mtd, NULL, &ppdata, + NULL, 0); + + if (err < 0) { + dev_err(&pdev->dev, "failed to register MTD\n"); + return err; + } + + string_get_size(info->mtd.size, STRING_UNITS_2, sz_str, + sizeof(sz_str)); + dev_info(&pdev->dev, "using %s SRAM on LP-8X4X as %s\n", sz_str, + dev_name(&info->mtd.dev)); + return 0; +} + +static int +lp8x4x_sram_remove(struct platform_device *dev) +{ + struct lp8x4x_sram_info *info = platform_get_drvdata(dev); + return mtd_device_unregister(&info->mtd); +} + +static struct platform_driver lp8x4x_sram_driver = { + .driver = { + .name = "sram-lp8x4x", + .owner = THIS_MODULE, + .of_match_table = of_flash_match, + }, + .probe = lp8x4x_sram_probe, + .remove = lp8x4x_sram_remove, +}; + +module_platform_driver(lp8x4x_sram_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Sergei Ianovich <ynvich@gmail.com>"); +MODULE_DESCRIPTION("MTD driver for SRAM on ICPDAS LP-8x4x");