[PATCH] mtd: rawnand: meson: fix the clock after discarding sd_emmc_c_clkc
Jerome Brunet
jbrunet at baylibre.com
Thu Jan 6 23:54:45 PST 2022
On Fri 07 Jan 2022 at 10:40, Liang Yang <liang.yang at amlogic.com> wrote:
> Hi Miquel,
>
> Meson NFC clock depends on the implementation of sd_emmc_c_clkc, but i
> don't find the commit in
> linux mainline. then the information i got from [jianxin.pan at amlogic.com]
> is the rejection of
> serial patches. I just look into the corresponding emails in link:
>
> https://lore.kernel.org/all/86789d73-5a6c-7729-ecd1-dcd342b2fcde@amlogic.com/
> it seems the patch never go on since V6, so [jianxin.pan at amlogic.com],
> could you help to clear it?
> let us address the discussion in another email from
> [jbrunet at baylibre.com].
That V6 was "rejected" because some comments from thre V5 were still not
addressed.
>
> On 2022/1/6 16:08, Miquel Raynal wrote:
>> [ EXTERNAL EMAIL ]
>> Hi Liang,
>> liang.yang at amlogic.com wrote on Thu, 6 Jan 2022 11:25:04 +0800:
>>
>>> 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 at 7000 {
>>> compatible = "amlogic,meson-axg-mmc-clkc", "syscon";
>>> reg = <0x0 0x7000 0x0 0x800>;
>>> };
>>>
>>> nand-controller at 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.
>> What is rejected?
>> Why is it rejected?
>> What is nand_divider?
> i simplify our clock framework below, so nand divider is SD_EMMC_CLOCK[5:0]
> here.
> ----- ----- -----
> the other------| \ | | | |
> | mux | ----- | N | ----------| NFC/|
> FCLK_DIV2------| | | | | EMMC|
> -----/ ----- -----
> SD_EMMC_CLOCK[7:6] SD_EMMC_CLOCK[5:0]
>>
>>>
>>> Change-Id: Ibeb4c7ff886f5886aac4d6c664d7bbd1b1bcb997
>> Change Ids are not expected in the upstream kernel.
>> But if you fix something you should have a Fixes:.
>>
>>> Signed-off-by: Liang Yang <liang.yang at amlogic.com>
>>> ---
>>> 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 at amlogic.com>
>>> */
>>> @@ -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;
>>> + 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);
>>> 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);
>>> 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 */
>>> 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);
>>> + 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));
>>> if (IS_ERR(nfc->reg_clk)) {
>>> dev_err(dev, "Failed to lookup clock base\n");
>>> return PTR_ERR(nfc->reg_clk);
>>
>> Thanks,
>> Miquèl
>> .
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