[PATCH v4 3/3] nvmem: rockchip-efuse: add rk3399-efuse support

Finley Xiao
2016-08-29T09:50:10Z

1) the efuse timing of rk3399 is different from earlier SoCs.
2) rk3399-efuse is organized as 32bits by 32 one-time programmable
electrical fuses, the efuse of earlier SoCs is organized as 32bits
by 8 one-time programmable electrical fuses with random access interface.

This patch adds a new read function for rk3399-efuse.

Signed-off-by: Finley Xiao <finley.xiao@rock-chips.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
---
drivers/nvmem/rockchip-efuse.c | 131 +++++++++++++++++++++++++++++++++++------
1 file changed, 112 insertions(+), 19 deletions(-)

diff --git a/drivers/nvmem/rockchip-efuse.c b/drivers/nvmem/rockchip-efuse.c
index 4d3f391..1825fd3 100644
--- a/drivers/nvmem/rockchip-efuse.c
+++ b/drivers/nvmem/rockchip-efuse.c
@@ -22,17 +22,29 @@
#include <linux/nvmem-provider.h>
#include <linux/slab.h>
#include <linux/of.h>
+#include <linux/of_platform.h>
#include <linux/platform_device.h>

-#define EFUSE_A_SHIFT 6
-#define EFUSE_A_MASK 0x3ff
-#define EFUSE_PGENB BIT(3)
-#define EFUSE_LOAD BIT(2)
-#define EFUSE_STROBE BIT(1)
-#define EFUSE_CSB BIT(0)
-
-#define REG_EFUSE_CTRL 0x0000
-#define REG_EFUSE_DOUT 0x0004
+#define RK3288_A_SHIFT 6
+#define RK3288_A_MASK 0x3ff
+#define RK3288_PGENB BIT(3)
+#define RK3288_LOAD BIT(2)
+#define RK3288_STROBE BIT(1)
+#define RK3288_CSB BIT(0)
+
+#define RK3399_A_SHIFT 16
+#define RK3399_A_MASK 0x3ff
+#define RK3399_NBYTES 4
+#define RK3399_STROBSFTSEL BIT(9)
+#define RK3399_RSB BIT(7)
+#define RK3399_PD BIT(5)
+#define RK3399_PGENB BIT(3)
+#define RK3399_LOAD BIT(2)
+#define RK3399_STROBE BIT(1)
+#define RK3399_CSB BIT(0)
+
+#define REG_EFUSE_CTRL 0x0000
+#define REG_EFUSE_DOUT 0x0004

struct rockchip_efuse_chip {
struct device *dev;
@@ -40,8 +52,8 @@ struct rockchip_efuse_chip {
struct clk *clk;
};

-static int rockchip_efuse_read(void *context, unsigned int offset,
- void *val, size_t bytes)
+static int rockchip_rk3288_efuse_read(void *context, unsigned int offset,
+ void *val, size_t bytes)
{
struct rockchip_efuse_chip *efuse = context;
u8 *buf = val;
@@ -53,27 +65,80 @@ static int rockchip_efuse_read(void *context, unsigned int offset,
return ret;
}

- writel(EFUSE_LOAD | EFUSE_PGENB, efuse->base + REG_EFUSE_CTRL);
+ writel(RK3288_LOAD | RK3288_PGENB, efuse->base + REG_EFUSE_CTRL);
udelay(1);
while (bytes--) {
writel(readl(efuse->base + REG_EFUSE_CTRL) &
- (~(EFUSE_A_MASK << EFUSE_A_SHIFT)),
+ (~(RK3288_A_MASK << RK3288_A_SHIFT)),
efuse->base + REG_EFUSE_CTRL);
writel(readl(efuse->base + REG_EFUSE_CTRL) |
- ((offset++ & EFUSE_A_MASK) << EFUSE_A_SHIFT),
+ ((offset++ & RK3288_A_MASK) << RK3288_A_SHIFT),
efuse->base + REG_EFUSE_CTRL);
udelay(1);
writel(readl(efuse->base + REG_EFUSE_CTRL) |
- EFUSE_STROBE, efuse->base + REG_EFUSE_CTRL);
+ RK3288_STROBE, efuse->base + REG_EFUSE_CTRL);
udelay(1);
*buf++ = readb(efuse->base + REG_EFUSE_DOUT);
writel(readl(efuse->base + REG_EFUSE_CTRL) &
- (~EFUSE_STROBE), efuse->base + REG_EFUSE_CTRL);
+ (~RK3288_STROBE), efuse->base + REG_EFUSE_CTRL);
udelay(1);
}

/* Switch to standby mode */
- writel(EFUSE_PGENB | EFUSE_CSB, efuse->base + REG_EFUSE_CTRL);
+ writel(RK3288_PGENB | RK3288_CSB, efuse->base + REG_EFUSE_CTRL);
+
+ clk_disable_unprepare(efuse->clk);
+
+ return 0;
+}
+
+static int rockchip_rk3399_efuse_read(void *context, unsigned int offset,
+ void *val, size_t bytes)
+{
+ struct rockchip_efuse_chip *efuse = context;
+ unsigned int addr_start, addr_end, addr_offset, addr_len;
+ u32 out_value;
+ u8 *buf;
+ int ret, i = 0;
+
+ ret = clk_prepare_enable(efuse->clk);
+ if (ret < 0) {
+ dev_err(efuse->dev, "failed to prepare/enable efuse clk\n");
+ return ret;
+ }
+
+ addr_start = rounddown(offset, RK3399_NBYTES) / RK3399_NBYTES;
+ addr_end = roundup(offset + bytes, RK3399_NBYTES) / RK3399_NBYTES;
+ addr_offset = offset % RK3399_NBYTES;
+ addr_len = addr_end - addr_start;
+
+ buf = kzalloc(sizeof(*buf) * addr_len * RK3399_NBYTES, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ writel(RK3399_LOAD | RK3399_PGENB | RK3399_STROBSFTSEL | RK3399_RSB,
+ efuse->base + REG_EFUSE_CTRL);
+ udelay(1);
+ while (addr_len--) {
+ writel(readl(efuse->base + REG_EFUSE_CTRL) | RK3399_STROBE |
+ ((addr_start++ & RK3399_A_MASK) << RK3399_A_SHIFT),
+ efuse->base + REG_EFUSE_CTRL);
+ udelay(1);
+ out_value = readl(efuse->base + REG_EFUSE_DOUT);
+ writel(readl(efuse->base + REG_EFUSE_CTRL) & (~RK3399_STROBE),
+ efuse->base + REG_EFUSE_CTRL);
+ udelay(1);
+
+ memcpy(&buf[i], &out_value, RK3399_NBYTES);
+ i += RK3399_NBYTES;
+ }
+
+ /* Switch to standby mode */
+ writel(RK3399_PD | RK3399_CSB, efuse->base + REG_EFUSE_CTRL);
+
+ memcpy(val, buf + addr_offset, bytes);
+
+ kfree(buf);

clk_disable_unprepare(efuse->clk);

@@ -89,7 +154,27 @@ static struct nvmem_config econfig = {
};

static const struct of_device_id rockchip_efuse_match[] = {
- { .compatible = "rockchip,rockchip-efuse", },
+ /* deprecated but kept around for dts binding compatibility */
+ {
+ .compatible = "rockchip,rockchip-efuse",
+ .data = (void *)&rockchip_rk3288_efuse_read,
+ },
+ {
+ .compatible = "rockchip,rk3066a-efuse",
+ .data = (void *)&rockchip_rk3288_efuse_read,
+ },
+ {
+ .compatible = "rockchip,rk3188-efuse",
+ .data = (void *)&rockchip_rk3288_efuse_read,
+ },
+ {
+ .compatible = "rockchip,rk3288-efuse",
+ .data = (void *)&rockchip_rk3288_efuse_read,
+ },
+ {
+ .compatible = "rockchip,rk3399-efuse",
+ .data = (void *)&rockchip_rk3399_efuse_read,
+ },
{ /* sentinel */},
};
MODULE_DEVICE_TABLE(of, rockchip_efuse_match);
@@ -99,6 +184,14 @@ static int rockchip_efuse_probe(struct platform_device *pdev)
struct resource *res;
struct nvmem_device *nvmem;
struct rockchip_efuse_chip *efuse;
+ const struct of_device_id *match;
+ struct device *dev = &pdev->dev;
+
+ match = of_match_device(dev->driver->of_match_table, dev);
+ if (!match || !match->data) {
+ dev_err(dev, "failed to get match data\n");
+ return -EINVAL;
+ }

efuse = devm_kzalloc(&pdev->dev, sizeof(struct rockchip_efuse_chip),
GFP_KERNEL);
@@ -116,7 +209,7 @@ static int rockchip_efuse_probe(struct platform_device *pdev)

efuse->dev = &pdev->dev;
econfig.size = resource_size(res);
- econfig.reg_read = rockchip_efuse_read;
+ econfig.reg_read = match->data;
econfig.priv = efuse;
econfig.dev = efuse->dev;
nvmem = nvmem_register(&econfig);
--
1.9.1