Hi Jianqun, Am Dienstag, 2. Dezember 2014, 23:04:57 schrieb Jianqun: > 在 12/01/2014 10:10 PM, Heiko Stübner 写道: > > Am Montag, 1. Dezember 2014, 15:34:41 schrieb Jianqun Xu: > >> Add driver for efuse found on rk3288 board based on rk3288 SoC. > >> Driver will read fuse information of chip at the boot stage of > >> kernel, this information new is for further usage. > >> > >> Signed-off-by: Jianqun Xu <jay.xu@xxxxxxxxxxxxxx> > > > > General question would be, what is the purpose of this driver? > > This driver will get efuse information, and other module will use it for > some useage, such as dvfs will ajust OPP according to the differences > between chips, that can make chips run on a powersave status > > Also can get the chip version... but this patch only show a part feathur just because I noticed this today, there seems to be an eeprom [0] and efuse [1] framework in the works. And as the mail from Maxime [2] suggests, both should probably merge. So the rockchip efuse driver should probably the framework that will become of those two. Heiko [0] https://lkml.org/lkml/2015/2/19/307 [1] https://lkml.org/lkml/2015/2/25/173 [2] https://lkml.org/lkml/2015/2/25/191 > > I don't see any publically usable functions and the only thing happening > > is > > the > > > > dev_info(efuse->dev, "leakage (%d %d %d)\n",... > > > > output that emits some information from the efuse to the kernel log? > > can I make it a node under some debug directory ? For now only show it in > boot message. > > In the dt-binding doc you write: > >> The 32x32 eFuse can only be accessed by APB bus when IO_SECURITYsel is > >> high.> > > While the TRM also says this, IO_SECURITY is not mentioned anywhere else > > in > > the document. Is this a pin or a bit somewhere in the GRF - i.e. something > > whichs state is readable? > > > > > > Some more comments inline. > > > >> --- > >> > >> arch/arm/mach-rockchip/efuse.c | 165 > >> > >> +++++++++++++++++++++++++++++++++++++++++ arch/arm/mach-rockchip/efuse.h > >> | > >> 15 ++++ > >> > >> 2 files changed, 180 insertions(+) > >> create mode 100644 arch/arm/mach-rockchip/efuse.c > >> create mode 100644 arch/arm/mach-rockchip/efuse.h > >> > >> diff --git a/arch/arm/mach-rockchip/efuse.c > >> b/arch/arm/mach-rockchip/efuse.c new file mode 100644 > >> index 0000000..326d81e > >> --- /dev/null > >> +++ b/arch/arm/mach-rockchip/efuse.c > > > > a driver like this should probably live in something like > > drivers/soc/rockchip. > > > >> @@ -0,0 +1,165 @@ > >> +/* mach-rockchip/efuse.c > >> + * > >> + * Copyright (c) 2014 Rockchip Electronics Co. Ltd. > >> + * Author: Jianqun Xu <jay.xu@xxxxxxxxxxxxxx> > >> + * > >> + * Tmis program is free software; you can redistribute it and/or modify > >> it > >> + * under the terms of version 2 of the GNU General Public License as > >> + * published by the Free Software Foundation. > >> + * > >> + * Tmis program is distributed in the hope that it will be useful, but > > > > type Tmis -> This > > > >> WITHOUT + * ANY WARRANTY; without even the implied warranty of > >> MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU > >> General Public License for + * more details. > >> + * > >> + * You should have received a copy of the GNU General Public License > >> along > >> with + * tmis program; if not, write to the Free Software Foundation, > >> Inc., > >> + * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA > >> + * > >> + * Tme full GNU General Public License is included in this distribution > >> in > >> the + * file called LICENSE. > >> + */ > >> + > >> +#include <linux/kernel.h> > >> +#include <linux/module.h> > >> +#include <linux/device.h> > >> +#include <linux/delay.h> > >> +#include <linux/platform_device.h> > >> +#include <linux/of_address.h> > >> +#include <linux/io.h> > >> + > >> +#include "efuse.h" > >> + > >> +#define EFUSE_BUF_SIZE (32) > >> +#define EFUSE_BUF_LKG_CPU (23) > >> +#define EFUSE_BUF_LKG_GPU (24) > >> +#define EFUSE_BUF_LKG_LOG (25) > > > > no braces needed for those numbers > > > >> + > >> +struct rk_efuse_info { > >> + /* Platform device */ > >> + struct device *dev; > >> + > >> + /* Hardware resources */ > >> + void __iomem *regs; > >> + > >> + /* buffer to store registers' values */ > >> + unsigned int buf[EFUSE_BUF_SIZE]; > >> +}; > >> + > >> +static void efuse_writel(struct rk_efuse_info *efuse, > >> + unsigned int value, > >> + unsigned int offset) > >> +{ > >> + writel_relaxed(value, efuse->regs + offset); > >> +} > >> + > >> +static unsigned int efuse_readl(struct rk_efuse_info *efuse, > >> + unsigned int offset) > >> +{ > >> + return readl_relaxed(efuse->regs + offset); > >> +} > > > > why these indirections for readl and writel? They don't seem to provide > > any > > additional benefit over calling writel_relaxed/readl_relaxed directly > > below.> > >> + > >> +static unsigned int rockchip_efuse_leakage(struct rk_efuse_info *efuse, > >> + int channel) > >> +{ > >> + switch (channel) { > >> + case EFUSE_BUF_LKG_CPU: > >> + case EFUSE_BUF_LKG_GPU: > >> + case EFUSE_BUF_LKG_LOG: > >> + return efuse->buf[channel]; > >> + default: > >> + dev_err(efuse->dev, "unknown channel\n"); > >> + return -EINVAL; > >> + } > >> + > >> + return 0; > >> +} > >> + > >> +static void rockchip_efuse_info(struct rk_efuse_info *efuse) > >> +{ > >> + dev_info(efuse->dev, "leakage (%d %d %d)\n", > >> + rockchip_efuse_leakage(efuse, EFUSE_BUF_LKG_CPU), > >> + rockchip_efuse_leakage(efuse, EFUSE_BUF_LKG_GPU), > >> + rockchip_efuse_leakage(efuse, EFUSE_BUF_LKG_LOG)); > >> +} > >> + > >> +static int rockchip_efuse_init(struct rk_efuse_info *efuse) > >> +{ > >> + int start = 0; > >> + int ret = 0; > >> + > >> + efuse_writel(efuse, EFUSE_CSB, REG_EFUSE_CTRL); > >> + efuse_writel(efuse, EFUSE_LOAD | EFUSE_PGENB, REG_EFUSE_CTRL); > >> + udelay(2); > >> + > >> + for (start = 0; start <= EFUSE_BUF_SIZE; start++) { > >> + efuse_writel(efuse, efuse_readl(efuse, REG_EFUSE_CTRL) & > >> + (~(EFUSE_A_MASK << EFUSE_A_SHIFT)), > >> + REG_EFUSE_CTRL); > >> + efuse_writel(efuse, efuse_readl(efuse, REG_EFUSE_CTRL) | > >> + ((start & EFUSE_A_MASK) << EFUSE_A_SHIFT), > >> + REG_EFUSE_CTRL); > >> + udelay(2); > >> + efuse_writel(efuse, efuse_readl(efuse, REG_EFUSE_CTRL) | > >> + EFUSE_STROBE, REG_EFUSE_CTRL); > >> + udelay(2); > >> + > >> + efuse->buf[start] = efuse_readl(efuse, REG_EFUSE_DOUT); > >> + > >> + efuse_writel(efuse, efuse_readl(efuse, REG_EFUSE_CTRL) & > >> + (~EFUSE_STROBE), REG_EFUSE_CTRL); > >> + udelay(2); > >> + } > >> + > >> + udelay(2); > >> + efuse_writel(efuse, efuse_readl(efuse, REG_EFUSE_CTRL) | > >> + EFUSE_CSB, REG_EFUSE_CTRL); > >> + udelay(2); > >> + > >> + return ret; > >> +} > >> + > >> +static int rockchip_efuse_probe(struct platform_device *pdev) > >> +{ > >> + struct rk_efuse_info *efuse; > >> + struct resource *mem; > >> + int ret = 0; > >> + > >> + efuse = devm_kzalloc(&pdev->dev, sizeof(*efuse), GFP_KERNEL); > >> + if (!efuse) > >> + return -ENOMEM; > >> + > >> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); > >> + efuse->regs = devm_ioremap_resource(&pdev->dev, mem); > >> + if (IS_ERR(efuse->regs)) > >> + return PTR_ERR(efuse->regs); > >> + > >> + platform_set_drvdata(pdev, efuse); > >> + efuse->dev = &pdev->dev; > >> + > >> + ret = rockchip_efuse_init(efuse); > >> + if (!ret) > >> + rockchip_efuse_info(efuse); > >> + > >> + return ret; > >> +} > >> + > >> +static const struct of_device_id rockchip_efuse_match[] = { > >> + { .compatible = "rockchip,rk3288-efuse", }, > > > > what about other Rockchip SoCs? At least the rk3188 seems to contain an > > efuse [though the TRM I have only directs to a RK3188 eFuse.pdf without > > describing the component. So I don't know if it's the same type. > > > >> + {}, > >> +}; > >> + > >> +static struct platform_driver rockchip_efuse_driver = { > >> + .probe = rockchip_efuse_probe, > >> + .driver = { > >> + .name = "rk3288-efuse", > >> + .owner = THIS_MODULE, > > > > .owner gets already set through module_platform_driver > > > >> + .of_match_table = of_match_ptr(rockchip_efuse_match), > >> + }, > >> +}; > >> + > >> +module_platform_driver(rockchip_efuse_driver); > >> + > >> +MODULE_DESCRIPTION("Rockchip eFuse Driver"); > >> +MODULE_AUTHOR("Jianqun Xu <jay.xu@xxxxxxxxxxxxxx>"); > >> +MODULE_LICENSE("GPL v2"); > >> diff --git a/arch/arm/mach-rockchip/efuse.h > >> b/arch/arm/mach-rockchip/efuse.h new file mode 100644 > >> index 0000000..3fdcf6d > >> --- /dev/null > >> +++ b/arch/arm/mach-rockchip/efuse.h > > > > why does this need to be a separate header? The stuff below could very > > well > > simply live inside the fuse.c > > > >> @@ -0,0 +1,15 @@ > >> +#ifndef _ARCH_ROCKCHIP_EFUSE_H_ > >> +#define _ARCH_ROCKCHIP_EFUSE_H_ > >> + > >> +/* Rockchip eFuse controller register */ > >> +#define EFUSE_A_SHIFT (6) > >> +#define EFUSE_A_MASK (0x3FF) > >> +#define EFUSE_PGENB (1 << 3) > > > > please use BIT(3) instead of (1 << 3) > > Same for the bits below. > > > >> +#define EFUSE_LOAD (1 << 2) > >> +#define EFUSE_STROBE (1 << 1) > >> +#define EFUSE_CSB (1 << 0) > >> + > >> +#define REG_EFUSE_CTRL (0x0000) > >> +#define REG_EFUSE_DOUT (0x0004) > > > > no braces necessary for basic numerals > > > >> + > >> +#endif /* _ARCH_ROCKCHIP_EFUSE_H_ */ -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
