From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Lucas Stach <l.stach@pengutronix.de>,
Philipp Zabel <p.zabel@pengutronix.de>,
Wolfram Sang <wsa@the-dreams.de>,
Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Subject: [PATCH 4.14 09/17] i2c: imx: use clk notifier for rate changes
Date: Fri, 20 Nov 2020 12:03:20 +0100 [thread overview]
Message-ID: <20201120104540.879118968@linuxfoundation.org> (raw)
In-Reply-To: <20201120104540.414709708@linuxfoundation.org>
From: Lucas Stach <l.stach@pengutronix.de>
commit 90ad2cbe88c22d0215225ab9594eeead0eb24fde upstream
Instead of repeatedly calling clk_get_rate for each transfer, register
a clock notifier to update the cached divider value each time the clock
rate actually changes.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/i2c/busses/i2c-imx.c | 32 +++++++++++++++++++++++++-------
1 file changed, 25 insertions(+), 7 deletions(-)
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -194,6 +194,7 @@ struct imx_i2c_dma {
struct imx_i2c_struct {
struct i2c_adapter adapter;
struct clk *clk;
+ struct notifier_block clk_change_nb;
void __iomem *base;
wait_queue_head_t queue;
unsigned long i2csr;
@@ -468,15 +469,14 @@ static int i2c_imx_acked(struct imx_i2c_
return 0;
}
-static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx)
+static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
+ unsigned int i2c_clk_rate)
{
struct imx_i2c_clk_pair *i2c_clk_div = i2c_imx->hwdata->clk_div;
- unsigned int i2c_clk_rate;
unsigned int div;
int i;
/* Divider value calculation */
- i2c_clk_rate = clk_get_rate(i2c_imx->clk);
if (i2c_imx->cur_clk == i2c_clk_rate)
return;
@@ -511,6 +511,20 @@ static void i2c_imx_set_clk(struct imx_i
#endif
}
+static int i2c_imx_clk_notifier_call(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct clk_notifier_data *ndata = data;
+ struct imx_i2c_struct *i2c_imx = container_of(&ndata->clk,
+ struct imx_i2c_struct,
+ clk);
+
+ if (action & POST_RATE_CHANGE)
+ i2c_imx_set_clk(i2c_imx, ndata->new_rate);
+
+ return NOTIFY_OK;
+}
+
static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
{
unsigned int temp = 0;
@@ -518,8 +532,6 @@ static int i2c_imx_start(struct imx_i2c_
dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
- i2c_imx_set_clk(i2c_imx);
-
imx_i2c_write_reg(i2c_imx->ifdr, i2c_imx, IMX_I2C_IFDR);
/* Enable I2C controller */
imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR);
@@ -1131,6 +1143,9 @@ static int i2c_imx_probe(struct platform
"clock-frequency", &i2c_imx->bitrate);
if (ret < 0 && pdata && pdata->bitrate)
i2c_imx->bitrate = pdata->bitrate;
+ i2c_imx->clk_change_nb.notifier_call = i2c_imx_clk_notifier_call;
+ clk_notifier_register(i2c_imx->clk, &i2c_imx->clk_change_nb);
+ i2c_imx_set_clk(i2c_imx, clk_get_rate(i2c_imx->clk));
/* Set up chip registers to defaults */
imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN,
@@ -1141,12 +1156,12 @@ static int i2c_imx_probe(struct platform
ret = i2c_imx_init_recovery_info(i2c_imx, pdev);
/* Give it another chance if pinctrl used is not ready yet */
if (ret == -EPROBE_DEFER)
- goto rpm_disable;
+ goto clk_notifier_unregister;
/* Add I2C adapter */
ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
if (ret < 0)
- goto rpm_disable;
+ goto clk_notifier_unregister;
pm_runtime_mark_last_busy(&pdev->dev);
pm_runtime_put_autosuspend(&pdev->dev);
@@ -1162,6 +1177,8 @@ static int i2c_imx_probe(struct platform
return 0; /* Return OK */
+clk_notifier_unregister:
+ clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb);
rpm_disable:
pm_runtime_put_noidle(&pdev->dev);
pm_runtime_disable(&pdev->dev);
@@ -1195,6 +1212,7 @@ static int i2c_imx_remove(struct platfor
imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2CR);
imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2SR);
+ clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb);
clk_disable_unprepare(i2c_imx->clk);
pm_runtime_put_noidle(&pdev->dev);
next prev parent reply other threads:[~2020-11-20 11:11 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-20 11:03 [PATCH 4.14 00/17] 4.14.208-rc1 review Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 01/17] powerpc/64s: Define MASKABLE_RELON_EXCEPTION_PSERIES_OOL Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 02/17] powerpc/64s: move some exception handlers out of line Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 03/17] powerpc/64s: flush L1D on kernel entry Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 04/17] powerpc: Add a framework for user access tracking Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 05/17] powerpc: Implement user_access_begin and friends Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 06/17] powerpc: Fix __clear_user() with KUAP enabled Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 07/17] powerpc/uaccess: Evaluate macro arguments once, before user access is allowed Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 08/17] powerpc/64s: flush L1D after user accesses Greg Kroah-Hartman
2020-11-20 11:03 ` Greg Kroah-Hartman [this message]
2020-11-20 11:03 ` [PATCH 4.14 10/17] i2c: imx: Fix external abort on interrupt in exit paths Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 11/17] gpio: mockup: fix resource leak in error path Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 12/17] powerpc/8xx: Always fault when _PAGE_ACCESSED is not set Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 13/17] Input: sunkbd - avoid use-after-free in teardown paths Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 14/17] mac80211: always wind down STA state Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 15/17] can: proc: can_remove_proc(): silence remove_proc_entry warning Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 16/17] KVM: x86: clflushopt should be treated as a no-op by emulation Greg Kroah-Hartman
2020-11-20 11:03 ` [PATCH 4.14 17/17] ACPI: GED: fix -Wformat Greg Kroah-Hartman
2020-11-21 11:46 ` [PATCH 4.14 00/17] 4.14.208-rc1 review Naresh Kamboju
2020-11-21 18:36 ` Guenter Roeck
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