[RFC v3 2/9] rework to use regmap

From: H. Nikolaus Schaller
Date: Sun Feb 16 2020 - 14:21:23 EST


From: Paul Cercueil <paul@xxxxxxxxxxxxxxx>

should/will be squashed into the previous commit ("nvmem: add driver for JZ4780 efuse")
but is kept separately for this RFC to make the modifications more transparent.
---
drivers/nvmem/jz4780-efuse.c | 179 ++++++++++++++++-------------------
1 file changed, 84 insertions(+), 95 deletions(-)

diff --git a/drivers/nvmem/jz4780-efuse.c b/drivers/nvmem/jz4780-efuse.c
index ac03e1900ef9..79dc42431bfe 100644
--- a/drivers/nvmem/jz4780-efuse.c
+++ b/drivers/nvmem/jz4780-efuse.c
@@ -30,38 +30,35 @@
#include <linux/regmap.h>
#include <linux/timer.h>

-#define JZ_EFUCTRL (0x0) /* Control Register */
-#define JZ_EFUCFG (0x4) /* Configure Register*/
-#define JZ_EFUSTATE (0x8) /* Status Register */
-#define JZ_EFUDATA(n) (0xC + (n)*4)
-
-#define JZ_EFUSE_START_ADDR 0x200
-
-#define JZ_EFUSE_EFUCTRL_CS BIT(30)
-#define JZ_EFUSE_EFUCTRL_ADDR_MASK 0x1FF
-#define JZ_EFUSE_EFUCTRL_ADDR_SHIFT 21
-#define JZ_EFUSE_EFUCTRL_LEN_MASK 0x1F
-#define JZ_EFUSE_EFUCTRL_LEN_SHIFT 16
-#define JZ_EFUSE_EFUCTRL_PG_EN BIT(15)
-#define JZ_EFUSE_EFUCTRL_WR_EN BIT(1)
-#define JZ_EFUSE_EFUCTRL_RD_EN BIT(0)
-
-#define JZ_EFUSE_EFUCFG_INT_EN BIT(31)
-#define JZ_EFUSE_EFUCFG_RD_ADJ_MASK 0xF
-#define JZ_EFUSE_EFUCFG_RD_ADJ_SHIFT 20
-#define JZ_EFUSE_EFUCFG_RD_STR_MASK 0xF
-#define JZ_EFUSE_EFUCFG_RD_STR_SHIFT 16
-#define JZ_EFUSE_EFUCFG_WR_ADJ_MASK 0xF
-#define JZ_EFUSE_EFUCFG_WR_ADJ_SHIFT 12
-#define JZ_EFUSE_EFUCFG_WR_STR_MASK 0xFFF
-#define JZ_EFUSE_EFUCFG_WR_STR_SHIFT 0
-
-#define JZ_EFUSE_EFUSTATE_WR_DONE BIT(1)
-#define JZ_EFUSE_EFUSTATE_RD_DONE BIT(0)
+#define JZ_EFUCTRL (0x0) /* Control Register */
+#define JZ_EFUCFG (0x4) /* Configure Register*/
+#define JZ_EFUSTATE (0x8) /* Status Register */
+#define JZ_EFUDATA(n) (0xC + (n)*4)
+
+#define EFUCTRL_ADDR_MASK 0x3FF
+#define EFUCTRL_ADDR_SHIFT 21
+#define EFUCTRL_LEN_MASK 0x1F
+#define EFUCTRL_LEN_SHIFT 16
+#define EFUCTRL_PG_EN BIT(15)
+#define EFUCTRL_WR_EN BIT(1)
+#define EFUCTRL_RD_EN BIT(0)
+
+#define EFUCFG_INT_EN BIT(31)
+#define EFUCFG_RD_ADJ_MASK 0xF
+#define EFUCFG_RD_ADJ_SHIFT 20
+#define EFUCFG_RD_STR_MASK 0xF
+#define EFUCFG_RD_STR_SHIFT 16
+#define EFUCFG_WR_ADJ_MASK 0xF
+#define EFUCFG_WR_ADJ_SHIFT 12
+#define EFUCFG_WR_STR_MASK 0xFFF
+#define EFUCFG_WR_STR_SHIFT 0
+
+#define EFUSTATE_WR_DONE BIT(1)
+#define EFUSTATE_RD_DONE BIT(0)

struct jz4780_efuse {
struct device *dev;
- void __iomem *iomem;
+ struct regmap *map;
struct clk *clk;
unsigned int rd_adj;
unsigned int rd_strobe;
@@ -71,59 +68,29 @@ struct jz4780_efuse {
static int jz4780_efuse_read_32bytes(struct jz4780_efuse *efuse, char *buf,
unsigned int addr)
{
- unsigned int tmp = 0;
- int i = 0;
- int timeout = 1000;
- int size = 32;
-
- /* 1. Set config register */
- tmp = readl(efuse->iomem + JZ_EFUCFG);
- tmp &= ~((JZ_EFUSE_EFUCFG_RD_ADJ_MASK << JZ_EFUSE_EFUCFG_RD_ADJ_SHIFT)
- | (JZ_EFUSE_EFUCFG_RD_STR_MASK << JZ_EFUSE_EFUCFG_RD_STR_SHIFT));
- tmp |= (efuse->rd_adj << JZ_EFUSE_EFUCFG_RD_ADJ_SHIFT)
- | (efuse->rd_strobe << JZ_EFUSE_EFUCFG_RD_STR_SHIFT);
- writel(tmp, efuse->iomem + JZ_EFUCFG);
-
- /*
- * 2. Set control register to indicate what to read data address,
- * read data numbers and read enable.
- */
- tmp = readl(efuse->iomem + JZ_EFUCTRL);
- tmp &= ~(JZ_EFUSE_EFUCFG_RD_STR_SHIFT
- | (JZ_EFUSE_EFUCTRL_ADDR_MASK << JZ_EFUSE_EFUCTRL_ADDR_SHIFT)
- | JZ_EFUSE_EFUCTRL_PG_EN | JZ_EFUSE_EFUCTRL_WR_EN
- | JZ_EFUSE_EFUCTRL_WR_EN);
-
- /* Need to select CS bit if address accesses upper 4Kbits memory */
- if (addr >= (JZ_EFUSE_START_ADDR + 512))
- tmp |= JZ_EFUSE_EFUCTRL_CS;
-
- tmp |= (addr << JZ_EFUSE_EFUCTRL_ADDR_SHIFT)
- | ((size - 1) << JZ_EFUSE_EFUCTRL_LEN_SHIFT)
- | JZ_EFUSE_EFUCTRL_RD_EN;
- writel(tmp, efuse->iomem + JZ_EFUCTRL);
-
- /*
- * 3. Wait status register RD_DONE set to 1 or EFUSE interrupted,
- * software can read EFUSE data buffer 0 - 8 registers.
- */
- do {
- tmp = readl(efuse->iomem + JZ_EFUSTATE);
- usleep_range(1000, 2000);
- if (timeout--)
- break;
- } while (!(tmp & JZ_EFUSE_EFUSTATE_RD_DONE));
-
- if (timeout <= 0) {
- dev_err(efuse->dev, "Timed out while reading\n");
- return -EAGAIN;
+ unsigned int tmp;
+ u32 ctrl;
+ int ret;
+ const int size = 32;
+
+ ctrl = (addr << EFUCTRL_ADDR_SHIFT)
+ | ((size - 1) << EFUCTRL_LEN_SHIFT)
+ | EFUCTRL_RD_EN;
+
+ regmap_update_bits(efuse->map, JZ_EFUCTRL,
+ (EFUCTRL_ADDR_MASK << EFUCTRL_ADDR_SHIFT) |
+ (EFUCTRL_LEN_MASK << EFUCTRL_LEN_SHIFT) |
+ EFUCTRL_PG_EN | EFUCTRL_WR_EN | EFUCTRL_RD_EN, ctrl);
+
+ ret = regmap_read_poll_timeout(efuse->map, JZ_EFUSTATE,
+ tmp, tmp & EFUSTATE_RD_DONE,
+ 1 * MSEC_PER_SEC, 50 * MSEC_PER_SEC);
+ if (ret < 0) {
+ dev_err(efuse->dev, "Time out while reading efuse data");
+ return ret;
}

- for (i = 0; i < (size / 4); i++)
- *((unsigned int *)(buf + i * 4))
- = readl(efuse->iomem + JZ_EFUDATA(i));
-
- return 0;
+ return regmap_bulk_read(efuse->map, JZ_EFUDATA(0), buf, size / sizeof(u32));
}

/* main entry point */
@@ -132,12 +99,13 @@ static int jz4780_efuse_read(void *context, unsigned int offset,
{
struct jz4780_efuse *efuse = context;
int ret;
+ const int size = 32;

while (bytes > 0) {
- unsigned int start = offset & ~(32 - 1);
- unsigned chunk = min(bytes, (start + 32 - offset));
+ unsigned int start = offset & ~(size - 1);
+ unsigned chunk = min(bytes, (start + size) - offset);

- if (start == offset && chunk == 32) {
+ if (start == offset && chunk == size) {
ret = jz4780_efuse_read_32bytes(efuse, val, start);
if (ret < 0)
return ret;
@@ -159,7 +127,7 @@ static int jz4780_efuse_read(void *context, unsigned int offset,
return 0;
}

-static struct nvmem_config jz4780_efuse_nvmem_config = {
+static __initdata struct nvmem_config jz4780_efuse_nvmem_config = {
.name = "jz4780-efuse",
.read_only = true,
.size = 1024,
@@ -169,28 +137,42 @@ static struct nvmem_config jz4780_efuse_nvmem_config = {
.reg_read = jz4780_efuse_read,
};

+static const struct regmap_config jz4780_efuse_regmap_config = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+ .max_register = JZ_EFUDATA(7),
+};
+
static int jz4780_efuse_probe(struct platform_device *pdev)
{
struct nvmem_device *nvmem;
struct jz4780_efuse *efuse;
- struct resource *res;
+ struct nvmem_config cfg;
unsigned long clk_rate;
struct device *dev = &pdev->dev;
+ void __iomem *regs;

- efuse = devm_kzalloc(&pdev->dev, sizeof(*efuse), GFP_KERNEL);
+ efuse = devm_kzalloc(dev, sizeof(*efuse), GFP_KERNEL);
if (!efuse)
return -ENOMEM;

- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- efuse->iomem = devm_ioremap(&pdev->dev, res->start, resource_size(res));
- if (IS_ERR(efuse->iomem))
- return PTR_ERR(efuse->iomem);
+ regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(regs))
+ return PTR_ERR(regs);
+
+ efuse->map = devm_regmap_init_mmio(dev, regs,
+ &jz4780_efuse_regmap_config);
+ if (IS_ERR(efuse->map))
+ return PTR_ERR(efuse->map);

- efuse->clk = devm_clk_get(&pdev->dev, "bus_clk");
+ efuse->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(efuse->clk))
return PTR_ERR(efuse->clk);

clk_rate = clk_get_rate(efuse->clk);
+
+ efuse->dev = dev;
/*
* rd_adj and rd_strobe are 4 bit values
* bus clk period * (rd_adj + 1) > 6.5ns
@@ -204,12 +186,18 @@ static int jz4780_efuse_probe(struct platform_device *pdev)
dev_err(&pdev->dev, "Cannot set clock configuration\n");
return -EINVAL;
}
- efuse->dev = dev;

- jz4780_efuse_nvmem_config.dev = &pdev->dev;
- jz4780_efuse_nvmem_config.priv = efuse;
+ regmap_update_bits(efuse->map, JZ_EFUCFG,
+ (EFUCFG_RD_ADJ_MASK << EFUCFG_RD_ADJ_SHIFT) |
+ (EFUCFG_RD_STR_MASK << EFUCFG_RD_STR_SHIFT),
+ (efuse->rd_adj << EFUCFG_RD_ADJ_SHIFT) |
+ (efuse->rd_strobe << EFUCFG_RD_STR_SHIFT));
+
+ cfg = jz4780_efuse_nvmem_config;
+ cfg.dev = &pdev->dev;
+ cfg.priv = efuse;

- nvmem = nvmem_register(&jz4780_efuse_nvmem_config);
+ nvmem = nvmem_register(&cfg);
if (IS_ERR(nvmem))
return PTR_ERR(nvmem);

@@ -245,5 +233,6 @@ module_platform_driver(jz4780_efuse_driver);

MODULE_AUTHOR("PrasannaKumar Muralidharan <prasannatsmkumar@xxxxxxxxx>");
MODULE_AUTHOR("H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>");
+MODULE_AUTHOR("Paul Cercueil <paul@xxxxxxxxxxxxxxx>");
MODULE_DESCRIPTION("Ingenic JZ4780 efuse driver");
MODULE_LICENSE("GPL v2");
--
2.23.0