* [RFC PATCH v2 0/2] mmc: renesas_sdhi: reset via reset controller @ 2021-02-22 11:39 Wolfram Sang 2021-02-22 11:39 ` [RFC PATCH v2 1/2] mmc: tmio: abort DMA before reset Wolfram Sang 2021-02-22 11:39 ` [RFC PATCH v2 2/2] mmc: renesas_sdhi: do hard reset if possible Wolfram Sang 0 siblings, 2 replies; 6+ messages in thread From: Wolfram Sang @ 2021-02-22 11:39 UTC (permalink / raw) To: linux-mmc; +Cc: linux-renesas-soc, Yoshihiro Shimoda, Wolfram Sang This series enables SDHI to be reset via a reset controller. Please let me know about your (and BSP team's) thoughts. Changes since (internal) RFC v1: * moved from probe() to the reset() callback so we use it for every reset, not only when initializing * patch 1 is new to make sure aborting DMA will work * added a comment about (unexpected) polling for the reset status * don't use atomic version for polling; reset is not a hot path Wolfram Sang (2): mmc: tmio: abort DMA before reset mmc: renesas_sdhi: do hard reset if possible drivers/mmc/host/renesas_sdhi.h | 2 ++ drivers/mmc/host/renesas_sdhi_core.c | 13 ++++++++++++- drivers/mmc/host/tmio_mmc_core.c | 4 ++-- 3 files changed, 16 insertions(+), 3 deletions(-) -- 2.30.0 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [RFC PATCH v2 1/2] mmc: tmio: abort DMA before reset 2021-02-22 11:39 [RFC PATCH v2 0/2] mmc: renesas_sdhi: reset via reset controller Wolfram Sang @ 2021-02-22 11:39 ` Wolfram Sang 2021-02-22 11:39 ` [RFC PATCH v2 2/2] mmc: renesas_sdhi: do hard reset if possible Wolfram Sang 1 sibling, 0 replies; 6+ messages in thread From: Wolfram Sang @ 2021-02-22 11:39 UTC (permalink / raw) To: linux-mmc; +Cc: linux-renesas-soc, Yoshihiro Shimoda, Wolfram Sang We will soon allow resetting the whole IP core via a reset controller. For this case, DMA must be terminated before the actual reset. For the other cases, it is probably better, too. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> --- drivers/mmc/host/tmio_mmc_core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/tmio_mmc_core.c b/drivers/mmc/host/tmio_mmc_core.c index 2478a91e84b2..0e7a2faa5238 100644 --- a/drivers/mmc/host/tmio_mmc_core.c +++ b/drivers/mmc/host/tmio_mmc_core.c @@ -172,11 +172,11 @@ static void tmio_mmc_reset(struct tmio_mmc_host *host) sd_ctrl_write16(host, CTL_RESET_SD, 0x0001); usleep_range(10000, 11000); + tmio_mmc_abort_dma(host); + if (host->reset) host->reset(host); - tmio_mmc_abort_dma(host); - if (host->pdata->flags & TMIO_MMC_SDIO_IRQ) { sd_ctrl_write16(host, CTL_SDIO_IRQ_MASK, host->sdio_irq_mask); sd_ctrl_write16(host, CTL_TRANSACTION_CTL, 0x0001); -- 2.30.0 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [RFC PATCH v2 2/2] mmc: renesas_sdhi: do hard reset if possible 2021-02-22 11:39 [RFC PATCH v2 0/2] mmc: renesas_sdhi: reset via reset controller Wolfram Sang 2021-02-22 11:39 ` [RFC PATCH v2 1/2] mmc: tmio: abort DMA before reset Wolfram Sang @ 2021-02-22 11:39 ` Wolfram Sang 2021-02-23 10:06 ` Geert Uytterhoeven 1 sibling, 1 reply; 6+ messages in thread From: Wolfram Sang @ 2021-02-22 11:39 UTC (permalink / raw) To: linux-mmc; +Cc: linux-renesas-soc, Yoshihiro Shimoda, Wolfram Sang Some SDHI instances can be reset via the reset controller. If one is found, use it instead of the custom reset. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> --- drivers/mmc/host/renesas_sdhi.h | 2 ++ drivers/mmc/host/renesas_sdhi_core.c | 13 ++++++++++++- 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/renesas_sdhi.h b/drivers/mmc/host/renesas_sdhi.h index cb962c7883dc..53eded81a53e 100644 --- a/drivers/mmc/host/renesas_sdhi.h +++ b/drivers/mmc/host/renesas_sdhi.h @@ -70,6 +70,8 @@ struct renesas_sdhi { DECLARE_BITMAP(smpcmp, BITS_PER_LONG); unsigned int tap_num; unsigned int tap_set; + + struct reset_control *rstc; }; #define host_to_priv(host) \ diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c index 158c21e5a942..a1de5c431f07 100644 --- a/drivers/mmc/host/renesas_sdhi_core.c +++ b/drivers/mmc/host/renesas_sdhi_core.c @@ -20,6 +20,7 @@ #include <linux/clk.h> #include <linux/delay.h> +#include <linux/iopoll.h> #include <linux/kernel.h> #include <linux/mfd/tmio.h> #include <linux/mmc/host.h> @@ -32,6 +33,7 @@ #include <linux/platform_device.h> #include <linux/pm_domain.h> #include <linux/regulator/consumer.h> +#include <linux/reset.h> #include <linux/sh_dma.h> #include <linux/slab.h> #include <linux/sys_soc.h> @@ -561,9 +563,16 @@ static int renesas_sdhi_prepare_hs400_tuning(struct mmc_host *mmc, struct mmc_io static void renesas_sdhi_reset(struct tmio_mmc_host *host) { struct renesas_sdhi *priv = host_to_priv(host); + int ret; u16 val; - if (priv->scc_ctl) { + if (!IS_ERR(priv->rstc)) { + reset_control_reset(priv->rstc); + /* Unknown why but without polling reset status, it will hang */ + read_poll_timeout(reset_control_status, ret, ret == 0, 1, 100, + false, priv->rstc); + priv->needs_adjust_hs400 = false; + } else if (priv->scc_ctl) { renesas_sdhi_disable_scc(host->mmc); renesas_sdhi_reset_hs400_mode(host, priv); priv->needs_adjust_hs400 = false; @@ -1076,6 +1085,8 @@ int renesas_sdhi_probe(struct platform_device *pdev, if (ret) goto efree; + priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL); + ver = sd_ctrl_read16(host, CTL_VERSION); /* GEN2_SDR104 is first known SDHI to use 32bit block count */ if (ver < SDHI_VER_GEN2_SDR104 && mmc_data->max_blk_count > U16_MAX) -- 2.30.0 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [RFC PATCH v2 2/2] mmc: renesas_sdhi: do hard reset if possible 2021-02-22 11:39 ` [RFC PATCH v2 2/2] mmc: renesas_sdhi: do hard reset if possible Wolfram Sang @ 2021-02-23 10:06 ` Geert Uytterhoeven 2021-02-23 10:17 ` Wolfram Sang 0 siblings, 1 reply; 6+ messages in thread From: Geert Uytterhoeven @ 2021-02-23 10:06 UTC (permalink / raw) To: Wolfram Sang; +Cc: Linux MMC List, Linux-Renesas, Yoshihiro Shimoda Hi Wolfram, On Mon, Feb 22, 2021 at 12:41 PM Wolfram Sang <wsa+renesas@sang-engineering.com> wrote: > Some SDHI instances can be reset via the reset controller. If one is > found, use it instead of the custom reset. > > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Thanks for your patch! > --- a/drivers/mmc/host/renesas_sdhi_core.c > +++ b/drivers/mmc/host/renesas_sdhi_core.c > @@ -561,9 +563,16 @@ static int renesas_sdhi_prepare_hs400_tuning(struct mmc_host *mmc, struct mmc_io > static void renesas_sdhi_reset(struct tmio_mmc_host *host) > { > struct renesas_sdhi *priv = host_to_priv(host); > + int ret; > u16 val; > > - if (priv->scc_ctl) { > + if (!IS_ERR(priv->rstc)) { "if (priv->rstc)" if the reset is made optional. > + reset_control_reset(priv->rstc); > + /* Unknown why but without polling reset status, it will hang */ > + read_poll_timeout(reset_control_status, ret, ret == 0, 1, 100, > + false, priv->rstc); > + priv->needs_adjust_hs400 = false; > + } else if (priv->scc_ctl) { > renesas_sdhi_disable_scc(host->mmc); > renesas_sdhi_reset_hs400_mode(host, priv); > priv->needs_adjust_hs400 = false; > @@ -1076,6 +1085,8 @@ int renesas_sdhi_probe(struct platform_device *pdev, > if (ret) > goto efree; > > + priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL); devm_reset_control_get_optional_exclusive()? + missing error handling (real errors and -EPROBE_DEFER). Perhaps you want to add a "select RESET_CONTROLLER" to "config MMC_SDHI"? > + > ver = sd_ctrl_read16(host, CTL_VERSION); > /* GEN2_SDR104 is first known SDHI to use 32bit block count */ > if (ver < SDHI_VER_GEN2_SDR104 && mmc_data->max_blk_count > U16_MAX) Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [RFC PATCH v2 2/2] mmc: renesas_sdhi: do hard reset if possible 2021-02-23 10:06 ` Geert Uytterhoeven @ 2021-02-23 10:17 ` Wolfram Sang 2021-02-23 10:20 ` Geert Uytterhoeven 0 siblings, 1 reply; 6+ messages in thread From: Wolfram Sang @ 2021-02-23 10:17 UTC (permalink / raw) To: Geert Uytterhoeven; +Cc: Linux MMC List, Linux-Renesas, Yoshihiro Shimoda [-- Attachment #1: Type: text/plain, Size: 470 bytes --] Hi Geert, > "if (priv->rstc)" if the reset is made optional. Yes, that would be better. > > + priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL); > > devm_reset_control_get_optional_exclusive()? > + missing error handling (real errors and -EPROBE_DEFER). OK. > Perhaps you want to add a "select RESET_CONTROLLER" to "config > MMC_SDHI"? Isn't "select" too strong for an optional feature? I'd think so. Thanks, Wolfram [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 833 bytes --] ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [RFC PATCH v2 2/2] mmc: renesas_sdhi: do hard reset if possible 2021-02-23 10:17 ` Wolfram Sang @ 2021-02-23 10:20 ` Geert Uytterhoeven 0 siblings, 0 replies; 6+ messages in thread From: Geert Uytterhoeven @ 2021-02-23 10:20 UTC (permalink / raw) To: Wolfram Sang; +Cc: Linux MMC List, Linux-Renesas, Yoshihiro Shimoda Hi Wolfram, On Tue, Feb 23, 2021 at 11:17 AM Wolfram Sang <wsa+renesas@sang-engineering.com> wrote: > > Perhaps you want to add a "select RESET_CONTROLLER" to "config > > MMC_SDHI"? > > Isn't "select" too strong for an optional feature? I'd think so. It depends. Why would you want to use the reset controller instead of the custom reset in the first place? Hmm, reminds me your patch doesn't explain the "why" part ;-) Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-02-23 10:21 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2021-02-22 11:39 [RFC PATCH v2 0/2] mmc: renesas_sdhi: reset via reset controller Wolfram Sang 2021-02-22 11:39 ` [RFC PATCH v2 1/2] mmc: tmio: abort DMA before reset Wolfram Sang 2021-02-22 11:39 ` [RFC PATCH v2 2/2] mmc: renesas_sdhi: do hard reset if possible Wolfram Sang 2021-02-23 10:06 ` Geert Uytterhoeven 2021-02-23 10:17 ` Wolfram Sang 2021-02-23 10:20 ` Geert Uytterhoeven
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