Re: [PATCH] mtd: rawnand: meson: fix the clock after discarding sd_emmc_c_clkc
From: Liang Yang
Date: Thu Jan 06 2022 - 23:04:52 EST
Hi Jerome,
On 2022/1/6 16:16, Jerome Brunet wrote:
[ EXTERNAL EMAIL ]
On Thu 06 Jan 2022 at 11:25, Liang Yang <liang.yang@xxxxxxxxxxx> wrote:
Because EMMC and NAND have the same control clock register, so we
implement a 'sd_emmc_c_clkc'. Previously DTS is defined as below:
sd_emmc_c_clkc: mmc@7000 {
compatible = "amlogic,meson-axg-mmc-clkc", "syscon";
reg = <0x0 0x7000 0x0 0x800>;
};
nand-controller@7800 {
......
clocks = <&clkc CLKID_SD_EMMC_C>,
<&sd_emmc_c_clkc CLKID_MMC_DIV>,
<&sd_emmc_c_clkc CLKID_MMC_PHASE_RX>,
<&sd_emmc_c_clkc CLKID_MMC_PHASE_TX>;
clock-names = "core", "device", "rx", "tx";
amlogic,mmc-syscon = <&sd_emmc_c_clkc>;
......
}
but in fact, above implementation is rejected. so now registering
a nand_divider.
Can you give a bit of context ? a link to the discussion rejecting this
Maybe I mistake the meaning of [jianxin.pan@xxxxxxxxxxx], so i need him
to clarify it.
As far as remember, things were getting done for A1 and stopped before
clock part was finished. I'm saying the change is wrong, just that a
discussion is needed before a decision is made.
ok.
previous discussion in this link:
https://lore.kernel.org/all/86789d73-5a6c-7729-ecd1-dcd342b2fcde@xxxxxxxxxxx/
it never go on since v6.
Change-Id: Ibeb4c7ff886f5886aac4d6c664d7bbd1b1bcb997
Signed-off-by: Liang Yang <liang.yang@xxxxxxxxxxx>
---
drivers/mtd/nand/raw/meson_nand.c | 88 +++++++++++++++++--------------
1 file changed, 49 insertions(+), 39 deletions(-)
diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
index ac3be92872d0..4472363059c2 100644
--- a/drivers/mtd/nand/raw/meson_nand.c
+++ b/drivers/mtd/nand/raw/meson_nand.c
@@ -2,7 +2,7 @@
/*
* Amlogic Meson Nand Flash Controller Driver
*
- * Copyright (c) 2018 Amlogic, inc.
+ * Copyright (c) 2018-2021 Amlogic, inc.
* Author: Liang Yang <liang.yang@xxxxxxxxxxx>
*/
@@ -10,6 +10,7 @@
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
+#include <linux/clk-provider.h>
#include <linux/mtd/rawnand.h>
#include <linux/mtd/mtd.h>
#include <linux/mfd/syscon.h>
@@ -55,6 +56,7 @@
#define NFC_REG_VER 0x38
#define NFC_RB_IRQ_EN BIT(21)
+#define NFC_CMD_FIFO_RESET BIT(31)
#define CMDRWGEN(cmd_dir, ran, bch, short_mode, page_size, pages) \
( \
@@ -104,6 +106,9 @@
#define PER_INFO_BYTE 8
+#define CLK_DIV_SHIFT 0
+#define CLK_DIV_WIDTH 6
+
struct meson_nfc_nand_chip {
struct list_head node;
struct nand_chip nand;
@@ -151,15 +156,15 @@ struct meson_nfc {
struct nand_controller controller;
struct clk *core_clk;
struct clk *device_clk;
- struct clk *phase_tx;
- struct clk *phase_rx;
I would have been nice to explain why these clock are no longer
required, in the change description maybe ?
i got the reply from our vlsi members that rx and tx doesn't make sense
to meson NFC timing. so previous commit about this should be wrong.
+ struct clk *nand_clk;
+ struct clk_divider nand_divider;
unsigned long clk_rate;
u32 bus_timing;
struct device *dev;
void __iomem *reg_base;
- struct regmap *reg_clk;
+ void __iomem *reg_clk;
struct completion completion;
struct list_head chips;
const struct meson_nfc_data *data;
@@ -406,12 +411,14 @@ static int meson_nfc_queue_rb(struct meson_nfc *nfc, int timeout_ms)
cmd = NFC_CMD_RB | NFC_CMD_RB_INT
| nfc->param.chip_select | nfc->timing.tbers_max;
writel(cmd, nfc->reg_base + NFC_REG_CMD);
-
+ meson_nfc_drain_cmd(nfc);
is this clock related ?
ok, i will split it in another patch.
ret = wait_for_completion_timeout(&nfc->completion,
msecs_to_jiffies(timeout_ms));
if (ret == 0)
ret = -1;
+ /* reset command fifo to avoid lock */
+ writel(NFC_CMD_FIFO_RESET, nfc->reg_base + NFC_REG_CMD);
Again, not seem to be clock related - does not belong in this patch
ok, i will split it in another patch.
return ret;
}
@@ -988,8 +995,9 @@ static const struct mtd_ooblayout_ops meson_ooblayout_ops = {
static int meson_nfc_clk_init(struct meson_nfc *nfc)
{
int ret;
+ struct clk_init_data init = {0};
+ const char *fix_div2_pll_name[1];
- /* request core clock */
Why is the comment bothering you ?
nfc->core_clk = devm_clk_get(nfc->dev, "core");
if (IS_ERR(nfc->core_clk)) {
dev_err(nfc->dev, "failed to get core clock\n");
@@ -1002,21 +1010,25 @@ static int meson_nfc_clk_init(struct meson_nfc *nfc)
return PTR_ERR(nfc->device_clk);
}
- nfc->phase_tx = devm_clk_get(nfc->dev, "tx");
- if (IS_ERR(nfc->phase_tx)) {
- dev_err(nfc->dev, "failed to get TX clk\n");
- return PTR_ERR(nfc->phase_tx);
- }
-
- nfc->phase_rx = devm_clk_get(nfc->dev, "rx");
- if (IS_ERR(nfc->phase_rx)) {
- dev_err(nfc->dev, "failed to get RX clk\n");
- return PTR_ERR(nfc->phase_rx);
- }
+ init.name = devm_kstrdup(nfc->dev, "nfc#div", GFP_KERNEL);
+ init.ops = &clk_divider_ops;
+ fix_div2_pll_name[0] = __clk_get_name(nfc->device_clk);
You should be using "fw_name" so CCF looks a DT directly, instead of this
ok
+ init.parent_names = fix_div2_pll_name;
+ init.num_parents = 1;
+ nfc->nand_divider.reg = nfc->reg_clk;
+ nfc->nand_divider.shift = CLK_DIV_SHIFT;
+ nfc->nand_divider.width = CLK_DIV_WIDTH;
+ nfc->nand_divider.hw.init = &init;
+ nfc->nand_divider.flags = CLK_DIVIDER_ONE_BASED |
+ CLK_DIVIDER_ROUND_CLOSEST |
+ CLK_DIVIDER_ALLOW_ZERO;
+
+ nfc->nand_clk = devm_clk_register(nfc->dev, &nfc->nand_divider.hw);
+ if (IS_ERR(nfc->nand_clk))
+ return PTR_ERR(nfc->nand_clk);
/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
- regmap_update_bits(nfc->reg_clk,
- 0, CLK_SELECT_NAND, CLK_SELECT_NAND);
+ writel(CLK_SELECT_NAND | readl(nfc->reg_clk), nfc->reg_clk);
ret = clk_prepare_enable(nfc->core_clk);
if (ret) {
@@ -1030,29 +1042,21 @@ static int meson_nfc_clk_init(struct meson_nfc *nfc)
goto err_device_clk;
}
- ret = clk_prepare_enable(nfc->phase_tx);
+ ret = clk_prepare_enable(nfc->nand_clk);
if (ret) {
- dev_err(nfc->dev, "failed to enable TX clock\n");
- goto err_phase_tx;
- }
-
- ret = clk_prepare_enable(nfc->phase_rx);
- if (ret) {
- dev_err(nfc->dev, "failed to enable RX clock\n");
- goto err_phase_rx;
+ dev_err(nfc->dev, "pre enable NFC divider fail\n");
+ goto err_nand_clk;
}
ret = clk_set_rate(nfc->device_clk, 24000000);
if (ret)
- goto err_disable_rx;
+ goto err_disable_clk;
return 0;
-err_disable_rx:
- clk_disable_unprepare(nfc->phase_rx);
-err_phase_rx:
- clk_disable_unprepare(nfc->phase_tx);
-err_phase_tx:
+err_disable_clk:
+ clk_disable_unprepare(nfc->nand_clk);
+err_nand_clk:
clk_disable_unprepare(nfc->device_clk);
err_device_clk:
clk_disable_unprepare(nfc->core_clk);
@@ -1061,8 +1065,7 @@ static int meson_nfc_clk_init(struct meson_nfc *nfc)
static void meson_nfc_disable_clk(struct meson_nfc *nfc)
{
- clk_disable_unprepare(nfc->phase_rx);
- clk_disable_unprepare(nfc->phase_tx);
+ clk_disable_unprepare(nfc->nand_clk);
clk_disable_unprepare(nfc->device_clk);
clk_disable_unprepare(nfc->core_clk);
}
@@ -1375,6 +1378,7 @@ static int meson_nfc_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct meson_nfc *nfc;
struct resource *res;
+ u32 ext_clk_reg;
int ret, irq;
nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
@@ -1396,9 +1400,15 @@ static int meson_nfc_probe(struct platform_device *pdev)
if (IS_ERR(nfc->reg_base))
return PTR_ERR(nfc->reg_base);
- nfc->reg_clk =
- syscon_regmap_lookup_by_phandle(dev->of_node,
- "amlogic,mmc-syscon");
+ ret = of_property_read_u32(pdev->dev.of_node,
+ "sd_emmc_c_clkc",
+ &ext_clk_reg);
+ if (ret) {
+ dev_err(dev, "failed to get NAND external clock register\n");
+ return ret;
+ }
+
+ nfc->reg_clk = devm_ioremap(&pdev->dev, ext_clk_reg, sizeof(int));
That's how you should get a register region.
If you want an example of a device claiming several region on amlogic,
have a look at the pinctrl driver.
ok
if (IS_ERR(nfc->reg_clk)) {
dev_err(dev, "Failed to lookup clock base\n");
return PTR_ERR(nfc->reg_clk);
.