Re: [PATCH v3 05/11] clk: davinci - add dm644x clock initialization

From: Murali Karicheri
Date: Mon Nov 05 2012 - 10:43:04 EST


On 11/03/2012 09:30 AM, Sekhar Nori wrote:
On 10/25/2012 9:41 PM, Murali Karicheri wrote:
This patch adds dm644x clock initialization code that consists of
clocks data for various clocks and clock register callouts to
various clock drivers. It uses following clk drivers for this

1. clk-fixed-rate - for ref clock
2. clk-mux - for mux at the input and output of main pll
3. davinci specific clk-pll for main pll clock
4. davinci specific clk-div for pll divider clock
5. clk-fixed-factor for fixed factor clock such as auxclk
6. davinci specific clk-psc for psc clocks

This patch also moves all of the PLL and PSC register definitions
from clock.h and psc.h under davinci to the clk/davinci folder so
that various soc specific clock initialization code can share these
definitions.
Except this patch does not move the defines, it creates a copy of them
(which is bad since you quickly lose track of which is the correct
copy). Is this done to avoid including mach/ header files here?
Yes.
It will
actually be better to include the mach/ files here as a temporary
solution and then remove the include mach/ files once all the SoCs have
been converted over.

I was thinking we are not allowed to include mach/* header files in driver files. But most of the clk drivers
such clk-imx28, spear6xx_clock.c. versatile/clk-integrator.c etc are including mach/ headers. One issue is that the definitions in pll.h are re-usable across other machines falling under c6x and Keystone (new device we are working on) as well. Where do we keep includes that can be re-used across different architectures? include/linux/platform_data/ ? I see clk-integrator.h, clk-nomadik.h and clk-u300 sitting there. So I suggest moving any header files that defines utility functions, register definitions across different architectures to include/linux/platform_data. Candidate files would be clock.h, pll.h, clk-psc.h, clk-pll.h and clk-div.h. This way these can be used across the above machines that use the above architectures. Can we do this in my next version? This way we don't have to make another move later. All these CLK IPs are re-used across multiple architectures and make perfect sense to me to move to the above folder.

Signed-off-by: Murali Karicheri <m-karicheri2@xxxxxx>
---
drivers/clk/davinci/dm644x-clock.c | 304 ++++++++++++++++++++++++++++++++++++
drivers/clk/davinci/pll.h | 83 ++++++++++
drivers/clk/davinci/psc.h | 215 +++++++++++++++++++++++++
3 files changed, 602 insertions(+)
create mode 100644 drivers/clk/davinci/dm644x-clock.c
create mode 100644 drivers/clk/davinci/pll.h
create mode 100644 drivers/clk/davinci/psc.h

+/* all clocks available in DM644x SoCs */
+enum dm644x_clk {
+ clkin, oscin, ref_clk_mux, pll1, pll1_plldiv_clk_mux, auxclk,
+ clk_pll1_sysclk1, clk_pll1_sysclk2, clk_pll1_sysclk3, clk_pll1_sysclk4,
+ clk_pll1_sysclk5, clk_pll1_sysclkbp, pll2, pll2_plldiv_clk_mux,
+ clk_pll2_sysclk1, clk_pll2_sysclk2, clk_pll2_sysclkbp, dsp, arm, vicp,
+ vpss_master, vpss_slave, uart0, uart1, uart2, emac, i2c, ide, asp,
+ mmcsd, spi, gpio, usb, vlynq, aemif, pwm0, pwm1, pwm2, timer0, timer1,
+ timer2, clk_max
+};
+
+static struct davinci_clk *psc_clocks[] = {
+ &clk_dsp, &clk_arm, &clk_vicp, &clk_vpss_master, &clk_vpss_slave,
+ &clk_uart0, &clk_uart1, &clk_uart2, &clk_emac, &clk_i2c, &clk_ide,
+ &clk_asp0, &clk_mmcsd, &clk_spi, &clk_gpio, &clk_usb, &clk_vlynq,
+ &clk_aemif, &clk_pwm0, &clk_pwm1, &clk_pwm2, &clk_timer0, &clk_timer1,
+ &clk_timer2
+};
You rely on perfect order between this array and dm644x_clk enum above.
Can you initialize this array using the enum as the index so that it is
clear. Current method is too error prone.

Ok. Will do.

Thanks,
Sekhar


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